Abstract:
An illumination lamp comprising: a cover including an engagement portion; a functional member including a light emitting element and a mounting portion, the light emitting element covered by the cover while the engagement portion is engaged with the mounting portion; and a designed member including a cover holder and a lock, the lock locking the functional member, and the cover holder holding the cover.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from Japanese patent Application No. 2009-021309 filed on Feb. 2, 2009 and No. 2009-026550 filed on Feb. 6, 2009, the entire subject matter of which is incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to an assembling structure for a vehicle room illumination lamp. Especially, the assemble structure includes a protection cover for preventing damage to a light source. The protection cover is attached to the illumination lamp not only during transportation of the illumination lamp but also after attachment of the illumination lamp to a room of a vehicle. 
       BRIEF DESCRIPTION OF THE RELATED ART 
     Related Art 1 
       [0003]    There are related vehicles provided with a room illumination lamp which is provided on a ceiling so as to be at a position close to a windshield. This room illumination lamp is provided separately from a dome lamp which is provided substantially at a center of the ceiling. In many cases, the illumination lamp adopts a bulb (an electrical bulb) which has a filament as a light source. 
         [0004]    There are also related vehicles provided with a vanity mirror and a sun visor. The sun visor protects occupant&#39;s eyes from bright sunlight. The vanity mirror is a small mirror used for applying make-up and is provided on the sun visor. In recent years, a prevalent related sun visor is provided with an additional illumination lamp in a vicinity of the vanity mirror and a cover for covering the mirrors in an openable fashion prevails. There is an increasing tendency that many room illumination lamps of these types are used on luxury models with additional values or convertibles which cannot have room illumination lamps provided thereon from the structural point of view. 
         [0005]    A related room illumination lamp described in JP-A-2005-238966, for example, is a room illumination lamp of the above described type. 
         [0006]    As is shown in  FIG. 22 , the related room illumination lamp is provided with a designed member  202  and a functional member  204 . The designed member  202  is configured by fixing a lens  210  to a housing  200 A. The housing  200 A is attachable to an opening  101  of an interior member  100 . An example of the interior member  100  is a ceiling to which the illumination lamp is attached. The functional member  204  is provided with a light source  203 . The light source  203  is a filament which emits light having a predetermined chromaticity. The functional member  204  is supported by the designed member  202  and disposed at a back side of the interior member  100 . The functional member  204  can be assembled together with the designed member  202  integrally. 
         [0007]    In the above reviewed related room illumination lamp, however, the light source  203  is particularly fragile because of its material characteristics. Therefore, it is worried that the light source  203  is broken by a force applied during transportation from a manufacturing stage to an assembling stage. To deal with this problem, there is a related countermeasure. In the related countermeasure, a designed member  202  and a functional member  204  are not assembled together but are left as separate component parts before transportation. As shown in  FIG. 23 , for example, a protection cover  300  specialized for protecting the light source  203  covers the light source provided on the functional member  204 . 
         [0008]    This light source protection cover  300  is removed after the transportation since the protection cover  300  is so large that the protection cover  300  hinders the assembling the functional member  204  with the designed member  202  integrally. Because of the above, as shown in  FIG. 22 , the functional member  204  is attached to the opening  101  of the interior member  100  of a vehicle while the fragile light source  203  is exposed to the outside in a bare condition. Therefore, there is a risk that the light source  203  is contacted with something and is broken. In addition, in a case where the light source  203  is broken due to a contact with the opening  101  of the interior member  100  or the like, there is a risk that the interior member  100  about the opening  101  of the vehicle is also damaged. 
       Related Art 2 
       [0009]    On a wall surface such as a ceiling in the inside of a vehicle, an indoor illumination lamp which illuminates the inside of the vehicle is mounted. Such an indoor illumination lamp includes a lamp unit constituted of a light source drive part, and a light source such as a bulb connected to the light source drive part so as to illuminate the inside of the vehicle. Such a lamp unit is mounted on a wall surface or an designed member arranged on the wall surface (hereinafter referred to as “wall surface or the like”). 
         [0010]    The above-mentioned lamp unit is assembled in a factory, is transported as a single unit to a vehicle on which the lamp unit is mounted and, thereafter, is mounted on a wall or the like of the vehicle. Accordingly, there is a possibility that the light source is damaged due to an impact from the outside or the like during the transportation of the lamp unit. The constitution which prevents the occurrence of such damages on the light source during the transportation is proposed in JP-A-2007-230254. 
         [0011]    A lamp protective cover  910  described in JP-A-2007-230254 which covers a lamp unit  930  having a light source includes, as shown in  FIG. 36 , a pair of body covering portions  911 ,  912  which is connected to each other by way of a hinge  913 , a pair of light source covering portions  914 ,  915  which is connected to the body covering portions  911 ,  912  respectively. The lamp protective cover  910  is formed by molding using a relatively thin resin. One body covering portion  911  is formed such that a ceiling plate  916  which is arranged on an upper side, a side plate  917  which is arranged on a right side, and a front plate  918  which is arranged on a front side surround the lamp unit  930  from three sides. The other body covering portion  912  is arranged in symmetry with one body covering portion  911  with respect to the hinge  913 , and is formed such that a ceiling plate  920  which is arranged on an upper side, a side plate  921  which is arranged on a left side, and a front plate  922  which is arranged on a front side surround the lamp unit  930  from three sides. 
         [0012]    In one light source covering portion  914 , a proximal end portion which is joined to the front plate  918  is formed in a semi-quadrangular cylindrical shape, a distal end portion is formed in a semi-spherical shape, and the inside of one light source covering portion  914  is communicated with the inside of one body covering portion  911 . The other light source covering part  915  is arranged in symmetry with one light source covering portion  914 . In the other light source covering part  915 , a proximal end portion which is joined to the front plate  922  is formed in a semi-quadrangular cylindrical shape, a distal end portion is formed in a semi-spherical shape, and the inside of the other light source covering part  915  is communicated with the inside of the other body covering portion  912 . 
         [0013]    The above-mentioned lamp protective cover  910  is mounted on the lamp unit  930  in such a manner that a light source (not shown in the drawing) is accommodated in the inside of the pair of light source covering portions  914 ,  915 , and a functional member body  931  is accommodated in the inside of the pair of body covering portions  911 ,  912 . In such a state, the lamp unit  930  is transported. Accordingly, the light source of the lamp unit  930  is covered with the pair of light source covering portions  914 ,  915  and hence, it is possible to prevent the light source from being damaged during transportation. 
         [0014]    However, the above-mentioned lamp protective cover  910  is removed from the lamp unit  930  at the time of mounting the lamp unit  930  on the designed member  940 . Accordingly, once the lamp unit  930  is mounted on a wall surface or the like of a vehicle together with the designed member  940 , the light source is no more protected so that there exists a possibility that the light source is damaged by water droplets from an area above a ceiling or the accumulation of dusts, for example. To prevent the light source from being damaged, it is thought that a protective member for protecting the light source is mounted on the lamp unit  930  after mounting the lamp unit  930  on the wall surface or the like of the vehicle. However, there exists a possibility that the mounting of the protective member increases the number of parts and the number of mounting man-hours thus pushing up a cost. 
       SUMMARY 
       [0015]    Exemplary embodiments of the present invention address the above disadvantage and other disadvantages not described above. 
         [0016]    Accordingly, it is an aspect of the present invention to provide an assembling structure for a vehicle room illumination lamp which can prevent a light source or an interior member of a vehicle from being damaged when the vehicle room illumination lamp is attached to the interior member of a vehicle. 
         [0017]    With a view to attaining the object, the invention provides an assembling structure for a vehicle room illumination lamp which will be described below. 
         [0018]    According to a first aspect of the invention, there is provided an assembling structure for a vehicle room illumination lamp comprising: a cover including an engagement portion; a functional member including a light emitting element and a mounting portion, the light emitting element covered by the cover while the engagement portion is engaged with the mounting portion; and a designed member including a cover holder and a lock, the lock locking the functional member, and the cover holder holding the cover. 
         [0019]    In exemplary embodiments, the cover includes a cutout portion. 
         [0020]    In exemplary embodiments, the cover includes a plurality of vent holes on a surface thereof. 
         [0021]    In exemplary embodiments, the cover includes a main body; a removable portion; and a connector connecting the main body and the removable portion, wherein the connector has an elongated shape which is defined by the cutout portion. 
         [0022]    In exemplary embodiments, the engagement portion is a projection, and the mounting portion is a groove. 
         [0023]    In exemplary embodiments, the designed member includes a bezel and a lens attached to the bezel, and the cover holder is provided between the bezel and the lens. 
         [0024]    In exemplary embodiments, the cover holder is a groove holding an end portion of at least one side surface of the cover. 
         [0025]    In exemplary embodiments, the cover includes a main body; and a pair of wall portions, each wall portion attached to the main body rotatable from an open condition where the light emitting element exposed between the wall portions to a closed condition where the wall portions cover the periphery of the light emitting element, the one of the wall portions having a first pawl, the other of the wall portions having a second pawl, wherein the first pawl and the second pawl are engaged each other in the closed condition. 
         [0026]    According to a second aspect of the invention, there is provided an assembling structure for a vehicle room illumination lamp with an opening provided on an interior member of a vehicle room including: a cover including a engagement portion; a functional member including a light emitting element and a mounting portion, the light emitting element covered by the cover mounted on the mounting portion; and a designed member including a cover holder, a bezel, and a claw, the cover holder holding the cover, the bezel attached to a periphery of the opening from one side of the opening, and the claw locked on the periphery from the other side of the opening. 
         [0027]    According to the assembling structure for a vehicle room illumination lamp of the first aspect of the invention, the functional member can be assembled to the designed member with the cover kept mounted thereon and has the shape which enables itself to pass through the opening, whereby the light source is protected by the cover when the room illumination lamp is assembled to a mounting portion of the vehicle. Consequently, a risk can be avoided of the light source or the periphery of a mounting portion on a vehicle side being damaged. In addition, even in the event that a different configuration is adopted to introduce a different variation to the functional member, since the cover can be used commonly, the molding costs for the cover can be suppressed. 
         [0028]    Also, according to the assembling structure for a vehicle room illumination lamp of the first aspect, the cover can be assembled to the functional member with the simple structure. 
         [0029]    Also, according to the assembling structure for a vehicle room illumination lamp of the first aspect, since the cover has the cutout, even in the event that a light source with high heat generating properties is illuminated for a long period of time, heat generated can be dissipated to the outside from the cutout, whereby the vehicle illumination lamp can be made highly safe even when the light source with high heat generating properties is used. 
         [0030]    Also, according to the assembling structure for a vehicle room illumination lamp of the first aspect, the cover has the plurality of vent holes which are formed therein, and even in the event that a light source with high heat generating properties is illuminated for a long period of time, heat generated can be dissipated to the outside from the portions where the vent holes are formed at the same time as light from the light source can be reflected substantially uniformly, whereby the vehicle illumination lamp can be made highly safe even when the light source with high heat generating properties is used. 
         [0031]    Also, according to the assembling structure for a vehicle room illumination lamp of the first aspect, even with a product produced to a single standard, the product can easily be modified to a construction having a high heat dissipating function according to an application to which the product is applied. Consequently, the assembling structure can finely deal with modifications according to types of illumination lamps and places and objects of installation thereof. 
         [0032]    Since the assembling structure for a vehicle room illumination lamp of the invention enables the functional member to be mounted in the opening in the interior member of the vehicle with the cover kept mounted thereon after transportation, an advantage can be provided that when the functional member is mounted in the opening, a risk can be avoided of the light source or the periphery of the opening on the vehicle side being damaged. 
         [0033]    Thus, the invention has been described briefly. Further, the details of the invention will be clarified further when the following exemplary embodiments of the invention are read by reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]      FIG. 1  is a perspective view showing a vehicle room illumination lamp according to a first exemplary embodiment of an assembling structure. 
           [0035]      FIG. 2  is an exploded perspective view showing a condition in which the vehicle room illumination lamp is attached to an interior member. 
           [0036]      FIG. 3  is a perspective view showing a condition in which the vehicle room illumination lamp has been attached to the interior member. 
           [0037]      FIG. 4  is a perspective view showing a condition in which a functional member is assembled with a designed member of the vehicle room illumination lamp. 
           [0038]      FIGS. 5A and 5B  are perspective views showing conditions before and after the cover is assembled with the designed members of the vehicle room illumination lamp, respectively. 
           [0039]      FIGS. 6A and 6B  are a perspective view and a side view, respectively, which illustrate a condition in which the cover is assembled with the designed member of the vehicle room illumination lamp. 
           [0040]      FIGS. 7A and 7B  are a perspective view and a side view, respectively, which illustrate a vehicle room illumination lamp according to a second exemplary embodiment of an assembling structure. 
           [0041]      FIG. 8  is an exploded perspective view showing a condition in which the vehicle room illumination lamp is mounted in an interior member. 
           [0042]      FIGS. 9A and 9B  are a perspective view and a side view, respectively, which illustrate a condition in which a cover is assembled with a designed member of the vehicle room illumination lamp. 
           [0043]      FIGS. 10A and 10B  are explanatory drawings showing a method adopted when a cutout is formed by removing part of the cover. 
           [0044]      FIG. 11  is a perspective view showing a condition in which the vehicle room illumination lamp is attached to the interior member. 
           [0045]      FIGS. 12A and 12B  are a perspective view and a side view, respectively, which illustrate a vehicle room illumination lamp according to a third exemplary embodiment of an assembling structure. 
           [0046]      FIG. 13  is an exploded perspective view showing a condition in which the vehicle room illumination lamp is attached to an interior member. 
           [0047]      FIGS. 14A and 14B  are perspective views showing front and rear postures of the vehicle room illumination lamp when the same lamp is attached to the interior member. 
           [0048]      FIG. 15  is an explanatory drawing showing a condition in which illumination light is reflected by a cover of the vehicle room illumination lamp. 
           [0049]      FIG. 16  is a perspective view showing a condition in which the vehicle room illumination lamp has been mounted in the interior member. 
           [0050]      FIG. 17  is a perspective view showing a vehicle room illumination lamp according to a fourth exemplary embodiment of an assembling structure. 
           [0051]      FIG. 18A  is a plan view showing the vehicle room illumination lamp, and  FIG. 18B  is an enlarged view of a main part thereof. 
           [0052]      FIG. 19  is an exploded perspective view showing a condition in which the vehicle room illumination lamp is attached to an interior member. 
           [0053]      FIG. 20A  is a perspective view showing a condition in which the vehicle room illumination lamp has been attached to in the interior member, and  FIG. 20B  is a sectional view taken along the line B-B in  FIG. 20A . 
           [0054]      FIG. 21  is a perspective view showing a condition in which the vehicle room illumination lamp attached to the interior member is viewed from therebelow. 
           [0055]      FIG. 22  is a sectional view showing a conventional room illumination lamp. 
           [0056]      FIGS. 23A and 23B  are explanatory drawings showing a condition before a light source protection cover is assembled with a functional member when the room illumination lamp is transported (A) and after the light source protection cover has been assembled with the functional member (B). 
           [0057]      FIG. 24  is an exploded perspective view of a lamp unit according to the fifth exemplary embodiment a vehicle room illumination lamp which includes such a lamp unit. 
           [0058]      FIG. 25  is a perspective view as viewed from a rear side of the lamp unit shown in  FIG. 24  before assembling. 
           [0059]      FIG. 26  is a side view of the lamp unit shown in  FIG. 24  before assembling. 
           [0060]      FIG. 27  is a perspective view as viewed from a front side of the lamp unit shown in  FIG. 24  after assembling. 
           [0061]      FIG. 28  is a front view of the lamp unit shown in  FIG. 27 . 
           [0062]      FIG. 29  is a perspective view showing a state in which a wall portion of the lamp unit shown in  FIG. 27  is closed. 
           [0063]      FIG. 30  is a bottom view of the lamp unit shown in  FIG. 29 . 
           [0064]      FIG. 31  is a perspective view showing a state before the lamp unit shown in  FIG. 27  is assembled to an designed member. 
           [0065]      FIG. 32  is a side view of the lamp unit and the designed member shown in  FIG. 31 . 
           [0066]      FIG. 33  is a cross-sectional view taken along a line X-X in  FIG. 31 . 
           [0067]      FIG. 34  is a perspective view showing a state after the lamp unit shown in  FIG. 27  is assembled to the designed member. 
           [0068]      FIG. 35  is a cross-sectional view taken along a line Y-Y in  FIG. 34 . 
           [0069]      FIG. 36  is a perspective view showing a related lamp unit. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0070]    Hereinafter, exemplary embodiments of the invention will be described in detail with reference to the accompanying drawings. 
       First Exemplary Embodiment 
       [0071]      FIGS. 1 and 2  show a vehicle room illumination lamp  1 A which is formed according to a first embodiment of an assembling structure for a vehicle room illumination lamp of the present invention. The vehicle room illumination lamp  1 A includes a designed member  10  and a functional member  20  which are integrally assembled together and a cover  30 . The vehicle room illumination lamp  1 A is fixed and attached to an opening R 1  of an interior member R such as a ceiling portion of a vehicle which constitutes a mounting portion. In the figures, reference character WH denotes a wire harness. 
         [0072]    The designed member  10  includes a housing  11  (described later). On the housing  11 , a lens  12 , a lock  13  and a ceiling pawl  14  are provided. The designed member  10  is to be integrally assembled with the functional member  20 . 
         [0073]    The housing  11  is to be attached to the opening R 1  which is provided in a surface of the interior member R within an interior of a vehicle. In this embodiment, the housing  11  is attached to a frame-like roof trim T which is fixedly provided along a circumferential edge of the opening R 1  in the interior member R. The roof trim T has a projecting shape which projects towards a deeper portion (an upper side in  FIG. 2 ) of the interior member R. The housing  11  is attached to the roof trim T so as to hold the roof trim T from the upside and the downside of the roof trim T. Specifically, in  FIG. 3 , the vehicle room illumination lamp  1 A is detachably attached to an interior member  2  while the roof trim T is held by a bezel  15  from the downside as indicated by broken line in  FIG. 3 , and by the ceiling pawl  14  of the housing  11  and the functional member  20  assembled with the housing  11  from the upside. The bezel  15  constitutes the outer circumferential edge of the housing  11 . 
         [0074]    In the housing  11 , as is shown in  FIG. 4 , the lens  12  is provided at a central portion, and this lens  12  is transparent or translucent so as to transmit light from a light source  21 . The lock  13  and the ceiling pawl  14  are provided in a vicinity of longitudinal ends of the housing  11 . 
         [0075]    Of these two members, the lock  13  includes a pair of flexible brackets  131  which erects from the housing  11  while facing each other. Each of the flexible brackets  131  can bend to some extent to expand a space defined therebetween. Each of the flexible brackets  131  is provided with a locking projection  131 A on an inner surface thereof respectively. 
         [0076]    The ceiling pawl  14  includes a thin plate-like body  141 , a thin plate-like neck  142 , and a head  143 . The body  141  erects from a front side (on a right-hand side in  FIGS. 1 to 4 ) of the bezel  15 . The neck  142  has a substantially U-shape which stretches continuously from the body  141 . The head  143  slopes from the neck  142  down to the front side of the bezel  15 . In particular, the body  141  and the neck  142  are configured to have spring characteristics which enable them to swing back and forth. The spring characteristics are originated from the thin plate shapes of the body  141  and the neck  142 . Whereby, the head  143  which constitutes a distal end of the ceiling pawl  14 , which slopes down from the end of the neck  142 , is allowed to be displaced in front and rear directions. 
         [0077]    A sloping surface of the head  143  has an unique shape and an unique inclination angle which are determined from the dynamics point of view. These unique shape and angle enable the following movement of the ceiling pawl  14 . When the designed member  10  is pushed to be inserted into the roof trim T from the downside (from below in  FIG. 3 ), the head  143  is firstly displaced to the rear (to the left in  FIG. 3 ) direction and passes through the opening R 1 . Once the head  143  passes through the opening R 1 , the head  143  returns to its regular position by the spring characteristics of the body  141  and the neck  142 . Thus, the designed member  10  is easily attached to the roof trim T. 
         [0078]    Further, as is shown in  FIGS. 1 ,  3  and  4 , a cover holder  16  is provided on the housing  11 . In the first embodiment, the cover holder  16  includes a substantially U-shaped groove. The cover holder  16  assists an engagement portion  31  to assemble a cover  30  with the functional member  20 . In other words, the cover holder  16  is provided so as to hold the cover  30  stably by detachably inserting an end portion of at least one side surface of the cover  30  into the U-shape grove while the cover  30  is assembled to the functional member  20  (the functional member will be described later). The groove which is included in the cover holder  16  of the embodiment is provided in a single location (on a near side in  FIG. 4 ) on one longitudinal side between the bezel  15  and the lens  12  and is surrounded by three erected walls (of which two facing walls are configured to have a triangular shape). To match this structure, as is shown in  FIGS. 2 and 3 , the roof trim T includes a cutout T 1  which the cover holder  16  enters. The roof trim T is fixedly provided on the circumferential edge portion of the opening R 1  in the interior member R. 
         [0079]    The functional member  20  includes, as is shown in  FIG. 5 , the light source  21 , lock pawls  22 , and wire holders  23 . The light source  21  is made up of a lamp or LED which illuminate an interior of the vehicle where it is installed. The lock pawls  22  can be locked in the lock  13  provided on the designed member  10  (refer to  FIG. 4 ). In addition, the functional member  20  includes a mounting portion where the cover  30  is detachably attached for protecting the light source  21  from impact particularly generated during transportation (while being carried). 
         [0080]    The lock pawls  22  detachably attach the functional member  20  to the designed member  10  by being locked with the lock  13  of the designed member  10 . Each of the lock pawls  22  has a bar shape (stick shape), projects perpendicular to a surface of the functional member  20 , and extends in the surface of the functional member  20  horizontally. The lock pawls  22  enter the lock  13  from thereabove so as to push the brackets  131  of the lock  13  to thereby expand the space defined therebetween, ride over the locking projections  131 A provided on the inner surfaces of the brackets  131  to penetrate further downwards than the projections and are then brought into engagement with the locking projections  131 A to be locked thereon. 
         [0081]    The cover  30  is detachably attached to the functional member  20  on the mounting portion  24 . The mounting portion  24  is a substantially circular fine groove lying between two walls rising on both sides thereof. 
         [0082]    The cover  30  provides a reflector function to reflect light emitted from the light source  21  in a direction in which the lens  12  is provided without any light leakage to the outside and a function to protect the light source  21  from dust and droplets of water. In addition to these functions, the cover  30  is designed to protect the light source  21  of the functional member  20  from impact applied from the outside particularly during transportation of the vehicle room illumination lamp  1 A and is mounted detachably on the functional member  20 . 
         [0083]    As is shown in  FIG. 6 , the cover  30  includes the engagement portion  31  which can be engaged with the fine groove which constitutes the mounting portion of the functional member  20 . This engagement portion  31  is made up of a pair of leg portions which project downwards from an inner surface side thereof or more specifically are made up of flexible locking projections which are formed into substantially arc-like shapes so as to approach each other to narrow a space therebetween at distal end sides thereof. By the locking means  31  so constructed being securely contained in the fine groove which constitutes the mounting portion  24 , the cover  30  is fixed to the functional member  20 . 
         [0084]    The cover  30  is designed to be held on the designed member  10  by at least one of end portions of both left and right side surfaces being inserted into the cover holder  16  which is made up of the substantially U-shaped receiving groove provided in the housing  11  of the functional member  20  so as to complement the stability when the cover  30  is mounted on the functional member  20  by the engagement portion  31 , whereby the cover  30  is held more stably. 
         [0085]    Next, there will be described a preliminary assembling method of the vehicle room illumination lamp  1 A according to the embodiment prior to transportation and an assembling method of assembling the same illumination lamp in the opening R 1  in the interior member R of the vehicle after arrival at an assembly site. 
         [0086]    (I) Preliminary Assembly for Transportation: 
         [0087]    Although a case will be described herein in which the cover  30  is assembled to the functional member  20  in advance based on  FIG. 4 , a configuration may be adopted in which the cover  30  is assembled to the functional member  20  after the functional member  20  is assembled to the designed member  10 . 
         [0088]    As is shown in  FIGS. 5A ,  5 B, when the cover  30  is assembled to the functional member  20 , the engagement portion  31  of the cover is fixedly fastened to the mounting portion  24  of the functional member  20 . 
         [0089]    Next, when the functional member  20  is assembled to the designed member  10 , the lock pawls  22  of the functional member  20  are brought into engagement with the locking projections  131 A of the lock  13  of the designed member  10  so that the lock pawls  22  are locked on the locking projections  131 A (refer to  FIG. 4 ). By this action, the vehicle room illumination lamp  1 A is built up in such a condition shown in  FIG. 1 . When the component parts are assembled together into the condition shown in  FIG. 1 , the light source  21  is protected from exterior impact by the cover  30  around the full circumference thereof, and the vehicle room illumination lamp  1 A is in a preferable condition for transport to the mounting site. 
         [0090]    (II) Assembly to Vehicle after Arrival at Vehicle Assembly Site: 
         [0091]    As is shown in  FIG. 1 , in the event that with the vehicle room illumination lamp built up, an upper portion of the vehicle room illumination lamp  1 A, that is, an upper portion side portion thereof which includes the functional member  20  and the ceiling pawl  14  of the designed member  10  is allowed to be inserted through the opening R 1  in the interior member R as it is, the upper portion side of the vehicle room illumination lamp  1 A is passed through the opening R 1  from the functional member  20  followed by the ceiling pawl  14 . 
         [0092]    Namely, in a last stage in which an upper side of the designed member  10  passes through the opening R 1 , the ceiling pawl  14  is elastically deformed by the neck portion  142  being bent largely, whereby the head portion  143  is pushed to be bent towards the erected portion  141 , so that the ceiling pawl  14  is allowed to pass through the opening R 1 . When the ceiling pawl  14  has passed through the opening R 1 , the ceiling pawl  14  is restored to its original condition by virtue of a restoration force of the head portion  143 , whereby the ceiling pawl  14  is locked on an upper surface of the roof trim T. On the other hand, a lower side portion of the designed member  10  which includes the bezel  15  and the like is not passed through the opening R 1 . As a result of this, the functional member  20  and the ceiling pawl  14  come to hold the roof trim T from an upper side and the bezel  15  of the designed member  10  comes to hold the roof trim T from a lower side thereof based on the opening R 1  in the roof trim T. By this configuration, the vehicle room illumination lamp  1 A can be mounted easily in the opening R 1  in the interior member R of the vehicle. 
         [0093]    In contrast, in the event that the upper portion side which includes the functional member  20  and the ceiling pawl  14  of the designed member  10  is not allowed to be inserted through the opening R 1  in the interior member R of the vehicle, the designed member  10  side and the functional member  20  side are temporarily disassembled as is shown in  FIG. 4 . As this occurs, however, the cover  30  may be kept assembled integrally to the functional member  20  as during transportation. Thereafter, only the functional member  20  side with the cover  30  kept mounted thereon is passed through the opening R 1 . As to the designed member  10  side, only the upper portion side, that is, only the ceiling pawl  14  is passed through the opening R 1 . (The size of integrally assemble of the cover  30  and the functional member  20  is smaller than the opening R 1 ) Then, the functional member  20  and the designed member  10  are assembled together, so that the roof trim T is held by the functional member  20  and the bezel  15  of the designed member  10  therebetween. 
         [0094]    By adopting this configuration, the vehicle room illumination lamp  1 A can be mounted in the opening R 1  in the interior member R on a ceiling portion of the vehicle which constitutes the mounting portion without removing the cover  30  from the functional member  20  laboriously. 
         [0095]    Consequently, according to the embodiment, with the cover  30  kept mounted on the functional member  20 , the light source  21  is protected from exterior impact by the cover  30 , which is preferable for safe transportation of the vehicle room illumination lamp  1 A to the mounting site. In addition, in mounting the vehicle room illumination lamp  1 A on the vehicle at the mounting site, the functional member  20  can be assembled to the designed member  10  with the cover  30  kept mounted on the functional member  20 , the workability at the time of assembly of the component parts being thereby enhanced. 
       Second Exemplary Embodiment 
       [0096]    Next, a second embodiment of the invention will be described. In this embodiment, like reference numerals will be given to like portions to those of the first embodiment, so as to avoid the repetition of like descriptions. 
         [0097]      FIGS. 7 and 8  show a vehicle room illumination lamp  1 B according to the second embodiment which is formed by applying an assembling structure for a vehicle room illumination lamp of the invention thereto. The vehicle room illumination lamp  1 B differs from the vehicle room illumination lamp  1 A of the first embodiment in that a cover having a cantilever construction is used in place of the cover  30 . 
         [0098]    In this vehicle room illumination lamp  1 B, in order to secure an anti-water-droplet function when the vehicle room illumination lamp  1 B is mounted in an opening R 1  in an interior member R, the vehicle room illumination lamp  1 B is fixedly disposed not in a ceiling portion of a vehicle as where the vehicle room illumination lamp  1 A of the first embodiment is disposed but in an interior member R on a vertical wall surface of a vehicle in a vertical direction (a direction in which gravity acts) in which droplets of water fall naturally. Namely, as is shown in  FIGS. 10 ,  11 , the vehicle room illumination lamp  1 B is installed so as to be erected while being oriented horizontally lengthways (in a horizontally collapsed condition) relative to a floor or the like of the vehicle. Specifically, the vehicle room illumination lamp  1 B is disposed so that a cutout portion (a removal portion  42  which will be described later) in a cover  40  lies on a lower side so as to prevent infiltration of droplets of water from the cutout portion. 
         [0099]    Namely, as is shown in  FIG. 9 , the cover  40  is made up of a main body  41  and removable portions  42  which are separated by slits  43  and are connected to the main body  41  only by narrow connectors  44 . 
         [0100]    Of these component parts, the main body  41  includes an engagement means  45  having the same configuration as that of the first embodiment which projects from a lower portion of an end face  411  which is suspended vertically from an inner wall surface. Namely, this engagement means  45  is made up of a pair of leg portions which project downwards from an inner surface side, so as to be inserted into a mounting portion  24  of a functional member  20  from thereabove to thereby be connected thereto. The mounting portion  24  is similar to that of the first embodiment and is made up of a substantially circular fine groove which lies between two walls which rise on both sides thereof. 
         [0101]    The removable portions  42  are connected to the main body  41  on both left- and right-hand sides thereof via the connectors  44  and can be removed from the main body  41  by cutting or bending either (or both) of the connector  44  so as to be cut apart from the main body  41 . By removing the removal portion  42  in the way described above, the cover  40  can exhibit a function to protect a light source  21  from dust and droplets of water and a function to protect the light source  21  during transportation, in addition to a function as a reflector. At the same time, a risk can be eliminated of the cover  40  being fused by heat generated and radiated from the light source  21 . 
         [0102]    In the event that the cover  40  (the main body  41 ) is given the function to protect the light source from dust and droplets of water, the portion resulting when the removal portion  42  is removed from the main body  41  must of course be oriented downwards, that is, the vehicle interior illumination light  1 B must be arranged in the way shown in  FIG. 10 . 
         [0103]    As has been described above, the connector  44  has the narrow shape which is defined between the left and right elongated slits  43 . The connector  44  is not limited to one which is made up of the narrow connector between the slits  43  but may be made up of grooves which are provided intermittently into a series of dots so as to be cut along the grooves. 
         [0104]    Next, there will be described a preliminary assembling method of the vehicle room illumination lamp  1 B according to the embodiment prior to transportation and an assembling method of assembling the same illumination lamp in the opening R 1  in the interior member R of the vehicle after arrival at an assembly site. 
         [0105]    (I) Preliminary Assembly for Transportation: 
         [0106]      FIG. 9  shows assembling work carried out at the time of loading for transportation. Although the functional member  20  will be described as being assembled to the designed member  10  in advance, the cover  40  may be assembled to the functional member  20  in advance. 
         [0107]    When the functional member  20  is assembled to the designed member  10 , similarly to the first embodiment, lock pawls  22  of the functional member  20  are fastened to a lock  13  of the designed member  10  so that the lock pawls  22  are locked on the lock  13  (refer to  FIG. 8 ). Thereafter, although the cover  40  is assembled to the functional member  20 , as is shown in  FIGS. 9A ,  9 B, an assembling method is totally the same as the method used in the first embodiment. By this action, the vehicle room illumination lamp  1 B is built up in such a condition shown in  FIG. 7 . In this embodiment, too, when the component parts are assembled together into the condition so shown, the light source  21  is protected from exterior impact by the cover  40 , and the vehicle room illumination lamp  1 B is in a preferable condition for transport to the mounting site. 
         [0108]    (II) Assembly to Vehicle after Arrival at Vehicle Assembly Site: 
         [0109]    In this case, the vehicle room illumination lamp  1 B can easily be mounted in the opening R 1  in the interior member R of the vehicle following a completely similar working procedure to that used in the first embodiment. Namely, the vehicle room illumination lamp  1 B can be mounted in the opening R 1  in such a condition that the same illumination lamp  1 B is built up as is shown in  FIG. 7 . By this configuration, the vehicle room illumination lamp  1 B can easily be mounted in the opening R 1  in the interior member R of the vehicle. 
         [0110]    In contrast, in the event that an upper portion side which includes the functional member  20  and a ceiling pawl  14  of the designed member  10  is not allowed to be inserted through the opening R 1  in the interior member R of the vehicle, the designed member  10  side and the functional member  20  side are temporarily disassembled, as is shown in  FIG. 8 . As this occurs, similarly to the first embodiment, the cover  40  may be kept assembled integrally to the functional member  20  as during transportation. 
         [0111]    By adopting this configuration, the vehicle room illumination lamp  1 B can be mounted in the opening R 1  in the interior member R on a ceiling portion of the vehicle which constitutes the mounting portion without removing the cover  40  from the functional member  20  laboriously. 
         [0112]    Consequently, according to the embodiment, similarly to the first embodiment, with the cover  40  kept mounted on the functional member  20 , the light source  21  is protected from exterior impact by the cover  40 , which is preferable for safe transportation of the vehicle room illumination lamp  1 B to the mounting site. In addition, in mounting the vehicle room illumination lamp  1 B on the vehicle at the mounting site, similarly to the first embodiment, the functional member  20  can be assembled to the designed member  10  with the cover  40  kept mounted on the functional member  20 , the workability at the time of assembly of the component parts being thereby enhanced. 
         [0113]    According to the embodiment, even in the event that much heat is radiated from the light source  21  by the light source  21  being kept illuminated for a long period of time, since the cover  40  is in the cantilever condition as is shown in  FIG. 11 , a high heat dissipating capability is ensured. In other words, since heat radiated from the light source  21  can be dissipated effectively from the opened portion in the cover  40  which is produced by removing one of the removable portions  42  of the cover  40 , there is caused no such situation that an interior of a space surrounded by the cover  40  is heated, whereby damage resulting from burning can be prevented, so as to realize safety at a high level. 
       Third Exemplary Embodiment 
       [0114]    Next, a third embodiment of the invention will be described. In this embodiment, like reference numerals will be given to like portions to those of the first embodiment and the second embodiment, so as to avoid the repetition of like descriptions. 
         [0115]      FIGS. 12 to 14  show a vehicle room illumination lamp  1 C according to the third embodiment which is formed by applying an assembling structure for a vehicle room illumination lamp of the invention thereto. The vehicle room illumination lamp  1 C differs from the vehicle room illumination lamp  1 B of the second embodiment in that either of left- and right-hand side portions of a main body  51  of a cover  50  is cut out in advance to form a cutout portion  52  where a function as a heat dissipating port (or a ventilation port) is given to the main body  51  in fabricating the cover  50 . 
         [0116]    In this embodiment, too, in order to provide an anti-water-droplet function for preference in addition to a heat dissipating function, the vehicle room illumination lamp  1 C is fixedly disposed not in a ceiling portion of a vehicle as in the first embodiment but in an interior member R on a vertical wall surface of a vehicle (in a vertical direction (a direction in which gravity acts) in which droplets of water fall naturally). Namely, as in the first embodiment, also in the vehicle room illumination lamp  1 C, a housing  11  is disposed so as to be erected relative to a floor or the like of the vehicle. Specifically, the vehicle room illumination lamp  1 C is disposed so that an opening in the cover  50  which is formed by partially cutting out the cover  50  lies on a lower side so as to prevent infiltration of droplets of water from the cut-out opening. 
         [0117]    The main body  51  differs from the main body  41  of the second embodiment which is formed into the polygonal shape by providing corners and has a curved surface which is curved into a smooth curve without any corner. In particular, an inner wall surface of this main body  51  is, as is shown in  FIG. 15 , is formed of a material containing a high reflective material so as to enhance a function as a reflection plate (a reflector) so that in light emitted from a light source  21 , light directed towards the inner wall surface of the main body  51  is reflected with a high reflectance factor and is directed in a direction in which a lens  12  resides. Similarly, the covers of the other embodiments than this embodiment can be formed of the same material so as to be given the same high reflecting function. Further, the covers of the respective embodiments including this embodiment may be formed of a material containing a diffusing material to reduce the reflectance factor, so that the brightness of illumination light from the light source  21  can be adjusted as required. 
         [0118]    Projecting portions  53 , which project in a rib-like fashion, are provided on outer circumferential edge portions of the main body  51  and inner circumferential edge portions which surround a cutout portion  52  so as to prevent condensed moisture or droplets of water from infiltrating an interior space surrounded by the main body  51  from the outer circumferential edge portions of the main body  51  and the inner circumferential edge portions of the cutout portion  52  even in case condensed moisture or droplets of water adhere to an outer surface of the main body  51 . 
         [0119]    Further, as is shown in  FIG. 14B , a water barrier wall  17  having a height h relative to a housing  11  of a designed member  10  is erected from the housing  11  in a position between a bezel  15  and the cover  50 . 
         [0120]    In order to provide the anti-water-droplet function for preference as described previously, when the housing  11  is disposed in the vertical direction which is erected relative to the floor of the vehicle as is shown in  FIG. 14B , the water barrier wall  17  is designed to be disposed on an upper side in the vertical direction. In addition, a groove  17 A is formed in the water barrier wall  17  so as to allow condensed moisture or droplets of water to escape downwards therefrom so as to eliminate a risk of such condensed moisture or droplets of water being accumulated at an upper portion of the water barrier wall  17  even in case condensed moisture or droplets of water are produced. 
         [0121]    Next, there will be described a preliminary assembling method of the vehicle room illumination lamp  1 C according to the embodiment prior to transportation and an assembling method of assembling the same illumination lamp in an opening R 1  in the interior member R of the vehicle after arrival at an assembly site. 
         [0122]    (I) Preliminary Assembly for Transportation: 
         [0123]      FIG. 12  shows assembling work carried out at the time of loading for transportation. In this case, similarly to the first and second embodiments, the functional member  20  may be assembled to the designed member  10  in advance, or the cover  50  may be assembled to the functional member  20  in advance. 
         [0124]    In this embodiment, too, a means for assembling the functional member  20  on to the designed member  10  and a means for assembling the cover  50  on to the functional member  20  are the same as those of the first and second embodiments. In this embodiment, too, since the light source  21  is protected from exterior impact by the cover  50 , the vehicle room illumination lamp  1 C is preferable for transportation to the mounting site. 
         [0125]    (II) Assembly to Vehicle after Arrival at Vehicle Assembly Site: 
         [0126]    In this case, too, the vehicle room illumination lamp  1 C can be mounted in the opening R 1  in the interior member R of the vehicle following a completely similar working procedure to that used in the first and second embodiments. 
         [0127]    In this way, in this embodiment, too, the vehicle room illumination lamp  1 C can be fixedly mounted in the opening R 1  in the interior member R on a ceiling portion of the vehicle which constitutes a mounting portion without removing the cover  50  from the functional member  20  laboriously. 
         [0128]    Consequently, according to the vehicle room illumination lamp  1 C of the embodiment, similarly to the first embodiment, with the cover  50  kept mounted on the functional member  20 , the light source  21  is protected from exterior impact by the cover  50 , which is preferable for safe transportation of the vehicle room illumination lamp  1 C to the mounting site. In addition, in mounting the vehicle room illumination lamp  1 C on the vehicle at the mounting site, similarly to the first embodiment, the functional member  20  can be assembled to the designed member  10  with the cover  50  kept mounted on the functional member  20 , the workability at the time of assembly of the component parts being thereby enhanced. 
         [0129]    According to the embodiment, similarly to the vehicle room illumination lamp  1 B of the second embodiment, even in the event that much heat is radiated from the light source  21  by the light source  21  being kept illuminated for a long period of time, the cutout portion  52  is formed to be opened in one side of the cover  50  as is shown in  FIGS. 12 and 16 . In other words, by providing the cutout portion  52  by partially cutting out one of both side surfaces of the cover, heat radiated from the light source  21  can be dissipated effectively from the cutout portion  52  which is an opening in the cover  50 , and therefore, there is caused no such situation that an interior of a space surrounded by the cover  50  is heated, whereby damage to the cover  50  resulting from burning can be prevented, so as to realize safety at a high level. 
         [0130]    Further, according to the embodiment, even in case condensed moisture or droplets of water are produced in the respective portions, such condensed moisture or droplets of water are prevented from infiltrating the interior of the housing  11  by the water barrier wall  17  which is installed to be disposed on the upper side in the vertical direction of the housing  11  and the projecting portions  53  which are provided along the outer circumferential edge portions of the cover  50  and the inner circumferential edge portions which face the cutout portion  52 . In addition, even in case the condensed moisture or droplets of water are allowed to infiltrate the main body  51  of the cover  50 , since the cutout portion  52  is provided in the main body  51  of the cover  50 , there is caused no such situation that condensed moisture or droplets of water are started to be accumulated on the main body  51  of the cover  50 . Even in case condensed moisture or droplets of water come to flow to an upper portion of the water barrier wall  17 , as is shown in  FIG. 14B , the groove  17 A in the water barrier wall  17  allows the moisture or droplets of water to escape downwards therefrom, thereby making it possible to avoid such a situation that condensed moisture or droplets of water are started to be accumulated on the water barrier wall  17 . 
       Fourth Exemplary Embodiment 
       [0131]    Next, a fourth embodiment of the invention will be described. In this embodiment, like reference numerals will be given to like portions to those of the first to third embodiments, so as to avoid the repetition of like descriptions. 
         [0132]      FIGS. 17 to 19  show a vehicle room illumination lamp  1 D according to the fourth embodiment which is formed by applying an assembling structure for a vehicle room illumination lamp of the invention thereto. The vehicle room illumination lamp  1 D differs from the vehicle room illumination lamp  1 C of the third embodiment in that in place of forming the cutout portion by cutting out either of the left- and right-hand side portions of the main body in advance, a plurality (a large number) of vent holes  61 A are formed in an outer circumferential surface of a main body  61  of a cover  60  as heat dissipating means (or ventilation means) for allowing air in an interior of the cover main body  61  to escape therefrom and that projecting portions  62  which are similar to the projecting portions  53  of the third embodiment are formed on outer circumferential edge portions of the main body  61 . 
         [0133]    In the vehicle room illumination lamp  1 D of this embodiment, too, an anti-water-droplet function is provided together with a function to protect a light source  21  during transportation and a heat dissipating function for dissipating heat generated from the light source  21  when it is illuminated. Because of this, although those functions can be obtained to some extent when the vehicle room illumination lamp  1 D is installed in a ceiling portion of a vehicle as in the first embodiment, in order to obtain those functions at higher levels, as in the second and third embodiments, the vehicle room illumination lamp  1 D is fixedly disposed in an interior member R on a vertical wall surface of the vehicle (in a vertical direction in which droplets of water fall naturally by the action of gravity), as is shown in  FIGS. 20 and 21 . 
         [0134]    Namely, also in the vehicle room illumination lamp  1 D of this embodiment, a housing  11  is disposed so as to be erected relative to a floor or the like of the vehicle as in the second and third embodiment. However, since no opening which is cut out largely is formed particularly in the cover  60 , the installed orientation of the vehicle room illumination lamp  1 D is not limited to the vertical direction in disposing the same illumination lamp. 
         [0135]    The ventilation holes  61 A are provided as a substitute for the openings which are provided in the second and third embodiments and prevent, similarly to the second and third embodiments, a failure or damage to the light source  21  due to condensed moisture or droplets of water produced on the vehicle side or dust. 
         [0136]    As is shown in  FIG. 18 , the vent holes  61 A of the embodiment are made up of a plurality of holes which are provided on a certain regular basis and have a construction which makes it difficult for droplets of water to pass therethrough. Namely, in these vent holes  61 A, for example, an opening edge portion of the vent hole  61 A is shaped to rise slightly from an inner surface to an outer surface of the main body  61  of the cover  60 , whereby even in case droplets of water adhere to the outer surface of the main body  61 , those droplets of water can be prevented from infiltrating an interior of the vent hole  61 A from the rising edge portion of the hole  61 A. In addition, by adopting this configuration, droplets of water can also be prevented from infiltrating the hole  61 A by the action of surface tension of the droplets of water. 
         [0137]    An assembling method of the vehicle room illumination lamp  1 D according to the embodiment for transportation and an assembling method of the same illumination lamp in an opening R 1  in an interior member R of a vehicle after arrival at the assembly site can be carried out in a procedure totally similar to that of the third embodiment. 
         [0138]    Consequently, when assembling the component parts of the vehicle room illumination lamp  1 D for transportation, in this embodiment, too, since the light source  21  is protected from exterior impact by the cover  60 , the assembling structure of the embodiment is preferable for transportation of the vehicle room illumination lamp  1 D to the mounting site. 
         [0139]    Also, when the vehicle interior illumination lamp  1 D is mounted on a vehicle after arrival at the assembly site, the vehicle interior illumination lamp  1 D can be mounted in an opening R 1  in an interior member R of a vehicle following the totally similar working procedure to those used in the first and second embodiments. 
         [0140]    In this way, in this embodiment, too, the vehicle room illumination lamp  1 D can be mounted in the opening R 1  in the interior member R of the vehicle which constitutes a mounting portion without removing the cover  60  from the functional member  20  laboriously. 
         [0141]    Consequently, according to this embodiment, similarly to the first embodiment, with the cover  60  kept mounted on the functional member  20 , since the light source is protected from exterior impact by the cover  60 , this configuration is preferable for safe transportation of the vehicle room illumination lamp  1 D to the mounting site. In addition, also when mounting the vehicle room illumination lamp  1 D on the vehicle at the mounting site, similarly to the first embodiment, the functional member  20  can be assembled on to a designed member  10  with the cover  60  kept mounted on the functional member  20 , the workability at the time of assembly of the component parts being thereby enhanced. 
         [0142]    According to the embodiment, similarly to the vehicle room illumination lamps  1 B,  1 C of the second and third embodiments, even in the event that much heat is radiated from the light source  21  by the light source  21  being kept illuminated for a long period of time, the vent holes  61 A are formed in the cover  60  as is shown in  FIG. 18 . In other words, since heat radiated from the light source  21  can be dissipated effectively from the vent holes  61 A which are open hole portions provided on substantially the full circumference of the cover  60 , there is caused no such situation that an interior of a space surrounded by the cover  60  is heated, whereby damage to the cover  60  resulting from burning can be prevented, so as to realize safety at a high level. 
         [0143]    Further, according to the embodiment, even in case condensed moisture or droplets of water are produced at an exterior portion of the cover  60 , such condensed moisture or droplets of water are interrupted by the water barrier wall  17  which is installed to be disposed on the upper side in the vertical direction of the housing  11  and the projecting portions  62  which are provided along the outer circumferential edge portions of the main body  61 , so that the condensed moisture or droplets of water are prevented from infiltrating the interior of the housing  11 . In addition, even in case such condensed moisture or droplets of water come to flow out to an upper portion of the water barrier wall  17 , the condensed moisture or droplets of water are allowed to escape downwards from a groove  17 A formed in the water barrier wall  17  as is shown in  FIG. 14B , thereby making it possible to avoid a risk of the condensed moisture or droplets of water starting to be accumulated at the upper portion of the water barrier wall  17 . 
         [0144]    According to the embodiment, since the vent holes  61 A of the embodiment are made up of the plurality of holes which are provided on the certain regular basis as is shown in  FIG. 18 , there can be provided another advantage that light from the light source can be reflected substantially uniformly. 
       Fifth Exemplary Embodiment 
     Added 
       [0145]    The fifth exemplary embodiment of the present invention is explained below with reference to  FIG. 24  to  FIG. 35 . 
         [0146]    A lamp unit (indicated by symbol  75  in the drawing), as shown in  FIG. 24 , constitutes an indoor illumination lamp  1  in such a manner that the lamp unit  75  is mounted on an trim  73   a  having an opening  74  which is formed on a ceiling  73  which constitutes an interior wall surface of a vehicle together with an designed member  76 . Further, the lamp unit  75  may be directly mounted on the ceiling  73  without interposing the designed member  76  therebetween. 
         [0147]    The lamp unit  75 , as shown in the respective drawings, includes a functional member  710  and a light source protective member  720 . 
         [0148]    The functional member  710  includes a light source driver  711  and a light source  718 . The light source driver  711  is, for example, made of a synthetic resin or the like and is formed into a box shape having an approximately T shape as viewed in a plan view consisting of a rectangular large-width portion  712  and a rectangular narrow-width portion  713  which are connected with each other. The light source driver  711  incorporates various circuit elements therein, and supplies electricity to the light source  718 . 
         [0149]    A wire harness  719  which is electrically connected with the above-mentioned various circuit elements are pulled out from both side surfaces of the large-width portion  712  which are arranged opposite to each other in the width direction (vertical direction in  FIG. 30 ). The wire harness  719  is arranged in the inside of the vehicle in a mutually bundled state, and end portions of the wire harness  719  are connected to a power source and the like not shown in the drawing. 
         [0150]    A pair of locking pawls  714 ,  715  is integrally formed on both side surfaces  13   a ,  13   b  of the narrow width portion  713  which are arranged opposite to each other in the width direction respectively. These pawls  714 ,  715  are engageable with brackets  744 ,  745  which are mounted on a housing  740  of the designed member  76  described later. The pair of locking pawls  714 ,  715  is formed in a projecting manner with a wedge shape in transverse cross section while having the longitudinal direction thereof directed parallel to the connection direction of the large-width portion  712  and the narrow-width portion  713  (lateral direction in  FIG. 30 ). A pair of flanges  716 ,  717  which projects in the direction orthogonal to the above-mentioned connection direction are formed, parallel to each other with an interval therebetween, on the other end portion of the narrow-width portion  13  opposite to one end portion which is connected to the large-width portion  712 . A spaced apart portion between the pair of flanges  716 ,  717  is formed into an approximately circular shape in cross section. A base portion  730  of the light source protective member  720  (cover) described later is mounted on the spaced-apart portion such that the base portion  730  grasps (sandwiches) the periphery of the spaced-apart portion and hence, the spaced-apart portion functions as a mounting portion  735  which supports the light source protective member  720 . 
         [0151]    The light source  718  is, for example, a well-known electric part such as a bulb or an LED which emits light when electricity is supplied. The light source  718  includes a semi-spherical distal end portion  718   a  and a cylindrical body portion  718   b  which is connected to the distal end portion  718   a . The light source  718  is mounted on the other end portion of the narrow-width portion  713  of the above-mentioned light source driver  711  in a state where the axial direction of the above-mentioned body portion  718   b  is arranged parallel to the above-mentioned connection direction, and the light source  718  projects from the light source driver  711 . The light source  718  is electrically connected with the above-mentioned various circuit elements incorporated into the light source driver  711 , and radiates light when electricity is supplied to the light source  718  from the light source driver  711 . 
         [0152]    The light source protective member  720  includes a cover body  736  and the base portion  730 . The cover body  736  includes wall portions  721 ,  722 ,  723 ,  724 ,  725  and hinges  726 ,  727 ,  728 ,  729 . 
         [0153]    The wall portion  721  includes a planar portion  721   a  having an approximately rectangular plate shape, a front surface portion  721   b  having an approximately triangular plate shape which is connected to one longitudinal end of the planar portion  721   a  orthogonal to the planar portion  721   a , a pawl portion  721   c , and a pair of ribs  721   d ,  721   e . The pawl portion  721   c  is formed on one lateral end of the planar portion  721   a  at a longitudinally center portion of the planar portion  721   a  in such a manner that the pawl portion  721   c  projects toward the other longitudinal end of the planar portion  721   a . The pair of ribs  721   d ,  721   e  is formed on the planar portion  721   a  in such a manner that the ribs  721   d ,  721   e  project in the direction opposite to the front surface portion  721   b . The pair of ribs  721   d ,  721   e  is arranged with an interval therebetween while the pawl portion  721   c  is positioned therebetween and the pair of ribs  721   d ,  721   e  is parallel to each other. Further, the longitudinal direction of the pair of ribs  721   d ,  721   e  is arranged along the lateral direction of the planar portion  721   a . With respect to the pair of ribs  721   d ,  721   e , one end portion of each rib is brought into contact with one lateral end of the planar portion  721   a . The rib  721   d  is arranged closer to the other longitudinal end of the planar portion  721   a  than the rib  721   e  is arranged and is formed shorter than the rib  721   e.    
         [0154]    The wall portion  722  includes a planar portion  722   a  having a rectangular shape, and a front surface portion  722   b  having an approximately triangular plate shape which is connected to one longitudinal end of the planar portion  722   a  orthogonal to the planar portion  722   a . With respect to the wall portion  722 , one lateral end of the planar portion  722   a  is rotatably (that is, in a bendable manner) connected to the other lateral end of the planar portion  721   a  of the wall portion  721  by way of a hinge  726 . 
         [0155]    The wall portion  723  includes a planar portion  723   a  having a rectangular shape, and a front surface portion  723   b  having an approximately triangular plate shape which is connected to one longitudinal end of the planar portion  723   a  orthogonal to the planar portion  723   a . With respect to the wall portion  723 , one lateral end of the planar portion  723   a  is rotatably connected to the other lateral end of the planar portion  722   a  of the wall portion  722  by way of a hinge  727 . Further, a full length of the planar portion  723   a  is set longer than full lengths of planer portions of other wall portions. The other longitudinal end of the planar portion  723   a  is connected to the base portion  730 . 
         [0156]    The wall portion  724  includes, in the same manner as the wall portion  722 , a planar portion  724   a  having a rectangular shape, and a front surface portion  724   b  having an approximately triangular plate shape which is connected to one longitudinal end of the planar portion  724   a  orthogonal to the planar portion  724   a . With respect to the wall portion  724 , one lateral end of the planar portion  724   a  is rotatably connected to the other lateral end of the planar portion  723   a  of the wall portion  723  by way of a hinge  728 . 
         [0157]    The wall portion  725  includes, in the same manner as the wall portion  721 , a planar portion  725   a  having an approximately rectangular plate shape, a front surface portion  725   b  having an approximately triangular plate shape which is connected to one longitudinal end of the planar portion  725   a  orthogonal to the planar portion  725   a , a pawl portion  725   c , and a pair of ribs  725   d ,  725   e . The pawl portion  725   c  is formed on one lateral end of the planar portion  725   a  at a longitudinally center portion of the planar portion  725   a  in such a manner that the pawl portion  725   c  projects toward one longitudinal end of the planar portion  725   a . The pair of ribs  725   d ,  725   e  is formed on the planar portion  725   a  in such a manner that the ribs  725   d ,  725   e  project in the direction opposite to the front surface portion  725   b . The pair of ribs  725   d ,  725   e  is arranged with an interval therebetween while the pawl portion  725   c  sandwiched therebetween and the pair of ribs  725   b ,  725   e  is parallel to each other. Further, the longitudinal direction of the pair of ribs  725   d ,  725   e  is arranged along the lateral direction of the planar portion  725   a . With respect to the pair of ribs  725   d ,  725   e , one end portion of each rib is brought into contact with one lateral end of the planar portion  725   a . The rib  725   d  is arranged closer to one longitudinal end of the planar portion  725   a  than the rib  725   e  is arranged and is formed shorter than the rib  725   e . With respect to the wall portion  725 , the other lateral end of the planar portion  725   a  is rotatably connected to the other lateral end of the planar portion  724   a  of the wall portion  724  by way of a hinge  729 . 
         [0158]    The wall portions  721 ,  722 ,  723 ,  724 ,  725  are formed using a hard synthetic resin or the like, for example. Full lengths (longitudinal lengths) and the widths (lateral lengths) of the planar portions  721   a ,  722   a ,  724   a ,  725   a  of the respective wall portions are set substantially equal to each other. The full length of the planar portion  723   a  is set larger than the full lengths of these planar portions, while the width of the planar portion  723   a  is set smaller than the widths of the respective planar portions. The hinges  726 ,  727 ,  728 ,  729  are formed using a synthetic resin or the like having resiliency, for example. The respective wall portions are connected in a juxtaposed manner with longitudinal directions of the respective planar portions thereof directed parallel to each other by the respective hinges. 
         [0159]    The respective wall portions are connected to each other in a bendable (rotatable) manner due to the respective hinges. The wall portions  721 ,  725  are openable and closeable in a double-hinged-door manner. Accordingly, by bending the respective hinges such that the wall portion  721  and the wall portion  725  are separated from each other, the respective wall portions are arranged in a semi-cylindrical shape such that the light source  718  is exposed toward the designed member (opened condition) (that is, toward the inside of the vehicle) ( FIG. 27 ,  FIG. 28 ). Alternatively, by bending the respective hinges such that the wall portion  721  and the wall portion  725  approach to each other, one lateral end of the planar portion  721   a  of the wall portion  721  and one lateral end of the planar portion  725   a  of the wall portion  725  are made to approach to each other thus arranging the respective wall portions into a cylindrical shape whereby the respective wall portions cover the periphery of the light source  718  (closed condition) ( FIG. 29 ,  FIG. 30 ). 
         [0160]    The front surface portions  721   b ,  722   b ,  723   b ,  724   b ,  725   b  formed on the respective wall portions form, when the respective wall portions are arranged in a cylindrical shape, one wall by abutting the edge portions thereof to each other thus covering the distal-end-portion  718   a  side of the light source  718 . Further, the pawl portion  721   c  and the pawl portion  725   c  described above are formed to engage with each other. Due to the engagement of the pawl portion  721   c  and the pawl portion  725   c , it is possible to maintain a state where one lateral end of the planar portion  721   a  of the wall portion  721  and one lateral end of the planar portion  725   a  of the wall portion  725  are arranged close to each other. That is, it is possible to maintain a state where the respective wall portions are arranged in a cylindrical shape. Further, the pawl portions  721   c ,  725   c  are formed so as to engage with pawl receiving portions  746   c ,  747   c  formed on the designed member  76  described later. 
         [0161]    The base portion  730  includes a base  731  (engagement portion), a pair of arms  732 ,  733 , and a guide projection  734 . The base  731  has an approximately rectangular plate shape, and the pair of arms  732 ,  733  is connected to both longitudinal end portions of the base  731  respectively in the direction orthogonal to the longitudinal direction. That is, the base  731  and the pair of arms  732 ,  733  are connected with each other in an approximately U shape. In the base portion  730 , a longitudinal center portion of the base  731  is connected to the other longitudinal end of the planar portion  723   a  in a state where the base portion  730  orthogonally intersects with the planar portion  723   a  of the above-mentioned wall portion  723 . The base portion  730  is arranged to face the front surface portion  723   b  of the wall portion  723  in an opposed manner with the planar portion  723   a  sandwiched therebetween. 
         [0162]    The pair of arms  732 ,  733  is elastically deformable, and a space which conforms to an outer profile of the above-mentioned mounting portion  735  is defined between the pair of arms  732 ,  733 . A distance between distal ends of the arms is set smaller than a diameter of the mounting portion  735 . Due to such a constitution, the mounting portion  735  can be inserted between the pair of arms  732 ,  733  and can be sandwiched by the pair of arms  732 ,  733 . That is, the mounting portion  735  is sandwiched between the pair of arms  732 ,  733  and hence, the light source protective member  720  is connected to the light source driver  711 . The guide projection  734  is mounted on the arm  733  in a projecting manner such that the longitudinal direction of the projection  734  is arranged parallel to the inserting direction of the mounting portion  735  into the space defined between the pair of arms  732 ,  733 . The guide projection  734  is brought into contact with the narrow-width portion  713  of the functional member  710  so as to guide the functional member  710  in the inserting direction when the mounting portion  735  is inserted into the space defined between the pair of arms  732 ,  733 . The guide projection  734  also suppresses a play between the functional member  710  and the base portion  730  (that is, light source protective member  720 ) after the mounting portion  735  is inserted. 
         [0163]    The designed member  76  includes the housing  740  and a lens portion  60 . 
         [0164]    The housing  740  includes a base portion  741 , an opening portion  742 , brackets  744 ,  745 , cover holders  746 ,  747 , and a ceiling pawl  748 . The base portion  741  is, for example, made of a synthetic resin or the like and is formed into an approximately rectangular plate shape, and the opening portion  742  which penetrates the base portion  741  in a rectangular shape is formed at the center of the base portion  741 . A pair of lens pawls  741   a ,  741   b  is respectively formed on both longitudinal end portions of the base portion  741 . 
         [0165]    The brackets  744 ,  745  are respectively formed of an elastically deformable plate, and are integrally formed on the base portion  741 . The brackets  744 ,  745  are formed on an upper surface of the base portion  741  (surface positioned at an upper side in  FIG. 31 ) in a vertically raised manner at a position closer to one longitudinal end portion of the base portion  741 . The brackets  744 ,  745  are arranged to face each other in an opposed manner in the lateral direction of the base portion  741  with a gap which is equal to a width of the above-mentioned narrow-width portion  713  therebetween. On inner surfaces (that is, opposedly facing surfaces) of the brackets  744 ,  745 , groove portions  744   a ,  745   a  which respectively engage with the pair of lock pawls  714 ,  715  formed on the above-mentioned narrow-width portion  713  are formed. Further, on distal ends of the brackets  744 ,  745 , inclined surfaces  744   b ,  745   b  which are gradually inclined inwardly corresponding to the increase of the distance from the distal ends toward proximal ends of the respective portions  744 ,  745  (toward a side where the respective portions  744 ,  745  are brought into contact with the base portion  41 ) are formed. 
         [0166]    By inserting the narrow-width portion  713  of the functional member  710  between inner sides of the brackets  744 ,  745 , the functional member  710  is sandwiched and fixed. When the narrow-width portion  713  is inserted between the brackets  744 ,  745 , firstly, both side surfaces of the narrow-width portion  713  are brought into contact with the inclined surfaces  744   b ,  745   b  respectively so that the narrow-width portion  713  is guided to the inside between the brackets  744 ,  745 . Further, when the insertion of the narrow-width portion  713  advances, the pair of lock pawls  714 ,  715  of the narrow-width portion  713  are respectively brought into contact with the inclined surfaces  744   b ,  745  so that the brackets  744 ,  745  are elastically deformed and are deflected in the direction that the brackets  744 ,  745  are separated from each other. When the insertion further advances, the pair of lock pawls  714 ,  715  gets over the inclined surfaces  744   b ,  745   b  and is fitted into the groove portions  744   a ,  745   a  so that the deformed brackets  744 ,  745  return to an original shape. Accordingly, the brackets  744 ,  45  fix the narrow-width portion  713  therebetween by clamping and, at the same time, the pair of lick pawls  714 ,  715  engage with the groove portions  744   a ,  745   a  respectively thus preventing the removal of the functional member  710 . 
         [0167]    The cover holders  746 ,  747  are respectively formed into a rectangular cylindrical shape having a rectangular transverse cross section. The cover holders  746 ,  747  are integrally mounted on an upper surface of the base portion  741  in a state that opening end portions of the rectangular cylinders are directed in the same direction as the upper surface of the base portion  741 . The cover holders  746 ,  747  are formed in a raised manner such that the longitudinal directions of the cover holders  746 ,  747  are arranged parallel to each other in the transverse cross section and face each other in the lateral direction of the base portion  741  with the opening  742  sandwiched therebetween. 
         [0168]    A longitudinal length of the cover holder  746  in transverse cross section is set substantially equal to a longitudinal length of the planar portion  721   a  of the wall portion  721 , while a lateral length of the cover holder  746  in transverse cross section is set substantially equal to a thickness of the planar portion  721   a  of the wall portion  721 . That is, cover holder  746  is formed such that one lateral end (indicated by symbol M in  FIG. 31 ) of the planar portion  721   a  can be inserted into the cover holder  746 . In the same manner as the cover holder  746 , a longitudinal length of the cover holder  747  in transverse cross section is substantially equal to a longitudinal length of the planar portion  725   a  of the wall portion  725 , and a lateral length of the cover holder  747  in transverse cross section is substantially equal to a thickness of the planar portion  725   a  of the wall portion  725 . That is, the cover holder  747  is formed such that one lateral end (indicated by symbol N in  FIG. 31 ) of the planar portion  725   a  can be inserted into the cover holder  747 . 
         [0169]    On an inner center portion of the cover holder  746 , a pawl receiving portion  46   c  which projects toward the other longitudinal end of the base portion  741  (that is, on a side opposite to the brackets  744 ,  745 ) is formed. Further, in a wall  461  of the cover holder  746  which is positioned closer to the lateral end portion of the base portion  741 , a pair of slits  746   a ,  746   b  is formed. When one end M of the planar portion  721   a  of the wall portion  721  is inserted into the cover holder  746 , the pawl receiving portion  746   c  and the pawl portion  721   c  of the wall portion  721  engage with each other so that the wall portion  721  is fixed to the cover holder  746 . Further, the ribs  721   d ,  721   e  formed on the wall portion  721  are inserted into the pair of slits  746   a ,  746   b  respectively thus preventing the occurrence of a play after fixing the wall portion  721 . 
         [0170]    In the same manner, on an inner center portion of the cover holder  747 , a pawl receiving portion  747   c  which projects toward one longitudinal end of the base portion  741  (that is, on a side of the brackets  744 ,  745 ) is formed. Further, in a wall  7471  of the cover holder  747  which is positioned closer to the lateral end portion of the base portion  741 , a pair of slits  747   a ,  747   b  is formed. When one end N of the planar portion  725   a  of the wall portion  725  is inserted into the cover holder  747 , the pawl receiving portion  747   c  and the pawl portion  725   c  of the wall portion  725  engage with each other so that the wall portion  725  is fixed to the cover holder  747 . Further, the ribs  725   d ,  725   e  formed on the wall portion  725  are inserted into the pair of slits  747   a ,  747   b  respectively thus preventing the occurrence of play after fixing the wall portion  725 . 
         [0171]    The ceiling pawl  748  is a member which is formed by bending an elongated planar plate into an approximately U shape, and is elastically deformable in the direction that a U-shaped width is narrowed. An erected portion  748   b  of the ceiling pawl  748  is integrally connected to the other longitudinal end portion of the base portion  741  in the vicinity of an edge portion of the opening portion  742 , while the head portion  748   c  of the ceiling pawl  748  forms an open end and is positioned in the vicinity of the other longitudinal end of the base portion  741  (that is, lens-portion mounting pawl  741   a ). An neck portion  748   a  which projects toward the outside from the other longitudinal end of the base portion  741  is formed on the head portion  748   c  of the ceiling pawl  748 . The ceiling pawl  748 , when the housing  740  is inserted into the opening  4  of the indoor illumination lamp mounting portion  3   a  of the ceiling portion  3 , is elastically deformed thus allowing the base portion  741  and the neck portion  748   a  to clamp the vicinity of the edge portion of the opening  74  of the indoor illumination lamp mounting portion  73   a  whereby the housing  740  (that is, indoor illumination lamp  1 ) is fixed to the ceiling  73 . 
         [0172]    The lens portion  760  includes a frame portion  761 , an opening portion  762  and a lens  763 . The frame portion  761  is formed into an approximately rectangular frame using a synthetic resin, and the opening portion  762  is formed inside the frame portion  761 . An outer size of the frame portion  761  is larger than a profile of the base portion  741  by one size. The opening portion  762  is formed in a shape substantially equal to the profile of the base portion  741 . A pair of mounting-pawl receiving portions  762   a ,  762   b  is formed on both longitudinal end portions of the opening portion  762  respectively. The pair of mounting-pawl receiving portions  762   a ,  762   b  engages with a pair of lens pawls  741   a ,  741   b  respectively thus fixing the lens portion  760  and the housing  740  to each other. The lens  763  is made of, for example, a transparent or semitransparent synthetic resin, glass or the like. The lens  763  is fitted into the opening portion  762  and allows a light which is radiated from the light source  718  to pass therethrough. 
         [0173]    Next, the assembling of the lamp unit  75  and the indoor illumination lamp  71  is explained. Firstly, the functional member  710  and the light source protective member  720  of the lamp unit  75  are assembled respectively. Here, with respect to the cover body  736  of the light source protective member  720 , the wall portion  721  and the wall portion  725  are opened in a double-hinged-door manner and are spaced apart from each other so that the respective wall portions are arranged in a semi-cylindrical shape. Next, as shown in  FIG. 25  and  FIG. 26 , the mounting portion  735  of the functional member  710  is inserted between the pair of arms  732 ,  733  of the base portion  730  of the light source protective member  720  so as to connect and fix the functional member  710  and the light source protective member  720  to each other as shown in  FIG. 27  and  FIG. 28 . 
         [0174]    Then, as shown in  FIG. 29  and  FIG. 30 , one lateral end M of the wall portion  721  and one lateral end N of the wall portion  725  are made to approach to each other so as to close a gap between these ends M,N, and the pawl portion  721   c  and the pawl portion  725   c  engage with each other thus arranging the respective wall portions in a cylindrical shape. Accordingly, the whole periphery of the light source  718  is covered with the cover body  736 . The lamp unit  75  is transported in such a state until the lamp unit  75  is mounted on a vehicle (transportation step in Claims). 
         [0175]    Then, the lamp unit  75  is mounted on the designed member  76  to which the housing  740  and the lens portion  760  are preliminarily assembled. Here, as shown in  FIG. 31 , the respective walls of the cover body  736  are arranged in a semi-cylindrical shape in such a manner that the pawl portion  721   c  and the pawl portion  725   c  are disengaged from each other, the wall portion  721  and the wall portion  725  are opened in a double-hinged-door manner so as to be separated from each other, and the light source  718  is exposed toward the inside of the vehicle through the opening portion  742  of the designed member  76 . (mounting step in Claims). Then, in the lamp unit  75 , as shown in  FIG. 32  and  FIG. 33 , the narrow-width portion  713  of the light source driver  711  is inserted between the brackets  744 ,  745  of the housing  740  and, at the same time, the lateral one end M of the wall portion  721  is inserted into the cover holder  746 , and the lateral one end N of the wall portion  725  is inserted into the cover holder  747 . As shown in  FIG. 34  and  FIG. 35 , the pair of locking pawls  714 ,  715  of the narrow-width portion  713  respectively engage with the groove portions  744   a ,  745   a  of the brackets  744 ,  745 , the pawl portion  721   c  of the wall portion  721  engages with the pawl receiving portion  746   c  of the cover holder  746 , and the pawl portion  725   c  of the wall portion  725  engages with the pawl receiving portion  747   c  of the cover holder  747 . Accordingly, the lamp unit  75  is mounted on the designed member  76  thus assembling the indoor illumination lamp  1 . Thereafter, the indoor illumination lamp  1  is mounted on the trim  73   a  mounted on the ceiling  73  in the inside of the vehicle. 
         [0176]    In this embodiment, the wall portions  721 ,  725  correspond to the lid portion and the pair of door portions in Claims. One lateral end M of the wall portion  721  and one lateral end N of the wall portion  725  correspond to the end portions of the pair of door portions in Claims respectively. The pawl portions  721   c ,  725   c  correspond to the engaging portions and the pair of pawl portions in Claims. 
         [0177]    As has been explained above, according to the present invention, the lamp unit includes the light source protective member  720  which includes the cover body  736  which is formed so as to cover the periphery of the light source  718  and is connected to the light source driver  711  by way of the base portion  730 , and the wall portions  721 ,  725  of the cover body  736  which are opened so as to expose the light source  718  toward the inside of the vehicle through the opening portion  742  of the designed member  76  when the light source driver  711  is mounted on the designed member  76 . Accordingly, at the time of transporting the lamp unit  75  or the like, before the light source driver  711  is mounted on the designed member  76 , the periphery of the light source  718  is covered with the cover body  736  and hence, it is possible to protect the light source  718  from an impact from the surrounding. Further, when the light source driver  711  is mounted on the designed member  76  in the vehicle, it is possible to expose the light source  718  toward the inside of the vehicle by opening the wall portions  721 ,  725  thus allowing the light source  718  to illuminate the inside of the vehicle and, at the same time, it is possible to protect the light source  718  from water droplets from an area above the ceiling  73  or dusts by the cover body  736 . Accordingly, the light source  718  can be protected after mounting the lamp unit to the interior wall surface of the vehicle or the like and, at the same time, the light source protection performance during the transportation can be enhanced. 
         [0178]    Further, the light source protective member  720  includes the pawl portions  721   c ,  725   c  which engage with the pawl receiving portions  746   c ,  747   c  of the cover holders  746 ,  747  of the designed member  76  when the light source driver  711  is mounted on the designed member  76 . Accordingly, the lamp unit  75  can be mounted on the designed member  76  at two portions consisting of the light source driver  711  and the light source protective member  720  and hence, the number of mounting portions is increased whereby it is possible to surely mount the lamp unit  75  on the designed member  76 . 
         [0179]    Further, the wall portions  721 ,  725  are configured to be openable and closeable in a double-hinged-door manner. The pawl portions  721   c ,  725   c  are mounted on one lateral end M of the wall portion  21  and one lateral end N of the wall portion  725  which are arranged close to each other when the wall portions  721 ,  725  are in a closed state such that the pawl portions  721   c ,  725   c  face each other in an opposed manner. The pawl portions  721   c ,  725   c  are formed such that the pawl portions  721   c ,  725   c  engage with the designed member  76  when the wall portions  721 ,  725  are in an open state and the pawl portions  721   c ,  725   c  engage with each other when the wall portions  721 ,  725  are in a closed state. Accordingly, the wall portions  721 ,  725  which constitute the light source protective member  720  can be mounted on the designed member  76  due to the engagement of the pawl portions  721   c ,  725   c  with the designed member  76 , and a state where the wall portions  721 ,  725  are closed can be maintained due to the engagement of the pawl portions  721   c ,  725   c  with each other. Accordingly, the pawl portions  721   c ,  725   c  can simultaneously perform the above-mentioned two functions thus providing the simple structure which does not require the provision of a plurality of engaging portions. 
         [0180]    In the above-mentioned embodiment, the light source protective member  720  includes the plurality of wall portions which are connected to each other in bendable manner from each other. However, the present invention is not limited to such an embodiment. For example, the present invention is applicable to any constitution provided that the cover body is formed so as to cover the periphery of the light source  718  and the lid portion (door portions) which is mounted on the cover body is openable so as to expose the light source  718  toward the inside of the vehicle when the light source driver  711  is mounted on the wall surface or the like. That is, the present invention is applicable to the constitution where the light source protective member includes a semi-cylindrical cover body and a pair of door portions which is rotatably connected to both edges of the cover body arranged opposite to each other in the direction orthogonal to the axial direction of the cover body and are openable and closeable in a double-hinged-door manner, the constitution where a single-swinging door portion is used in place of a pair of doors which is openable and closeable in a double-hinged-door manner. 
         [0181]    The above-mentioned embodiment merely exemplifies a typical mode of the present invention and hence, the present invention is not limited to the embodiment. That is, various modifications can be carried out without departing from the gist of the present invention.