Patent Document

CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is based on and incorporates by references Japanese Patent Application No. 2005-094178, which was filed on Mar. 29, 2005, and No. 2005-345480, which was filed on Nov. 30, 2005.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to an indicator lamp for a vehicle interior, and specifically relates to the indicator lamp that enables to be attached to a door trim where rainwater can be fallen.  
         [0003]     An indicator lamp is installed in a device of the vehicle interior. The indicator lamp indicates status information of the device, such as setting information, an on/off information or an abnormal information. The device is mainly located in an instrument panel. Recently, the large numbers of vehicles have been stolen, and an antitheft device has been developed. An indicator lamp, which indicates the working status of the antitheft device, is located in the instrument panel, above the instrument panel, or on a sun visor. The indicator lamp is also used as a warning lamp to a person who approaches the vehicle. In this case, the indicator lamp should be highly visible. Thus, the indicator lamp is preferably located in the door, especially in upper part of a door trim. The indicator lamp requires high reliability and low power consumption during times when the engine of the vehicle is stopped. Therefore, a light emitting diode (LED) is desirable to be used for the indicator lamp because the LED works with low power consumption.  
         [0004]     The door of the vehicle includes a lot of devices, for example, a glass, a glass elevation device, a door lock device, and an audio device. The door trim includes an inside door handle and a storage space for maps and magazines. The door trim also includes thick buffering parts for protecting a passenger and for insulating noise. Therefore, space for installing the indicator lamp in the door or the door trim is restricted by many devices and parts. Because the door trim is elaborately designed parts, the indicator lamp is limited by the door trim design in its size and its attachment structure. In case the indicator lamp is located on the upper part of the door trim, the indicator lamp is required to be waterproofed because rainwater falls on the upper part of the door trim when the door or window is open.  
         [0005]     As shown in  FIG. 1 , a light source of a lamp unit  1  is an LED lamp  2 . The LED lamp  2  includes an LED chip (not shown) that is bonded on a metal lead frame  3  and is enclosed by epoxy resin. The lamp unit  1  includes a bezel  7  on a top of a casing  8 . The lead frame  3  extends to a connector  5  through a circuit part  4 .  
         [0006]     The lamp unit  1  needs space or an insulating material therein to avoid electrical short. Thus, the lamp unit  1  needs to have a wide housing. In case that the lamp unit  1  is longer than the lead frame  3 , the lead frame  3  has to be extended by a connection  6 . When the lamp unit  1  includes a printed substrate, the lamp unit  1  needs to have a wide housing. The epoxy resin of the LED lamp  2  is visible as a light emitting part, the appearance of the light emitting part is less attractive. Because the LED lamp  2  is located near the bezel  7  of the lamp unit  1 , water can directly come in the LED lamp  2  when it rains. Thus, the lamp unit  1  is not water proof.  
       SUMMARY OF THE INVENTION  
       [0007]     An object of the invention is to overcome the above-mentioned limitations. An indicator lamp according to the present invention allows an attachment to a door trim. The indicator lamp can protect its light source from rainwater.  
         [0008]     Exemplarily, the invention is enabled as an indicator lamp for providing a warning signal to a person who approaches the vehicle to steal a vehicle. The indicator lamp includes a lamp unit including a light emitting diode (LED) . The indicator lamp includes a light guide conveying light from the LED. The light guide is shaped in a portion to cover at least a part of the lamp unit in a manner that prevents contaminations from entering the lamp unit.  
         [0009]     In another aspect of the invention, the invention is exemplarily a light guide for a vehicle indicator lamp assembly having a lamp unit with at least one light emitting diode (LED). The light guide includes a first portion that is shaped to cover at least a portion of the lamp unit in a manner that prevents contaminations from entering the lamp unit. The light guide also includes a second portion that is shaped to convey light emitted from the at least one light emitting diode (LED) in the lamp unit to be light emitted from the vehicle lamp assembly.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The accompanying figures, in which like reference numerals refer to identical or functionally similar elements throughout the separate views and which, together with the detailed description below, are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.  
         [0011]      FIG. 1  is a prior art of an indicator lamp;  
         [0012]      FIG. 2  is a sectional view at A-A line of  FIG. 9 ;  
         [0013]      FIG. 3  is an exploded view of a lamp unit;  
         [0014]      FIG. 4  is a perspective view of the indicator lamp  
         [0015]      FIG. 5  is a side view of the indicator lamp in  FIG. 4 ;  
         [0016]      FIG. 6  is a cross sectional view of the indicator lamp  1  at B-B line of  FIG. 5 ;  
         [0017]      FIG. 7  is an enlarged view of a light emitting part of the indicator lamp;  
         [0018]      FIG. 8  is a partial view of the indicator lamp at C-C line of  FIG. 7 ;  
         [0019]      FIG. 9  is a perspective view of a door trim which the indicator lamp is exemplarily applied to;  
         [0020]      FIG. 10  is a perspective view of the indicator lamp;  
         [0021]      FIG. 11  is a perspective view of a lamp unit with a light guide; and  
         [0022]      FIG. 12  is a cross sectional view of the indicator lamp in  FIG. 11 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     First Exemplary Embodiment  
       [0023]     Referring to  FIGS. 3 and 4 , an indicator lamp  10  includes a lamp unit  20 , a light guide  30  and a design bezel  50 . The lamp unit  20  includes a casing  22  and a cover  23 . The casing  22  includes a circuit  24  that mounts a circuit part  25  and an LED lamp  21 . The casing  22  includes engaging claws  26  that engage with the light guide  30 . The cover  23  covers the casing  21 . The LED lamp  21  includes an enclosed type LED that encloses an LED chip (not shown) by epoxy resin. The LED lamp  21  can also includes a surface mounted diode (SMD) type LED instead of the enclosed type LED. The LED lamp  21  can mount a single LED chip or multiple LED chips. The LED lamp  21  can also mount a single color LED chip or multiple colors LED chips. The SMD type LED can mount not only a 0.3-mm-square chip (small chip) but also a 1.0-mm-square chip (large chip) . A large chip LED can apply a larger amount of current and emits a brighter light than that of small chip.  
         [0024]     As shown in  FIGS. 4-6 , the light guide  30  includes an elongated portion  31  and a cover portion  32 . The elongated portion  31  and the cover portion  32  of the light guide  30  are integrally formed, exemplarily from polycarbonate resin. The elongated portion  31  receives a light from the LED lamp  21  at a bottom end  33  that connects with the cover portion  32 . Then, the elongated portion  31  conveys the light from the LED lamp  21  to a light emitting end  34 . Thus, the light from the LED lamp  21  is emitted at the light emitting end  34 . As shown in  FIGS. 7 and 8 , the light emitting end  34  includes protrusions. These protrusions function as a diffuser that diffuses the light from the LED lamp  21 . Hooks  35  of the light guide  30  engages with the design bezel  50 . The engaging claws  26  of the lamp unit  20  engage with engaging holes  36  of the cover portion  32  of the light guide  30 . When the light guide  30  connects with the lamp unit  20 , the LED lamp  21  is located between the engaging hole  36  and the bottom end  33  of the elongated portion  31 . Thus, the cover portion  32  of light guide  30  covers the LED lamp  21  of the lamp unit  20 . Therefore, the light guide  30  prevents contaminations from entering the lamp unit  20 .  
         [0025]     Still referring to  FIGS. 4-6 , the design bezel  50  is formed in a tubular shape and formed exemplarily from ABS resin. The design bezel  50  includes a rim  51  at a top portion of the design bezel  50 . As shown in  FIG. 2 , the design bezel  50  is inserted into an attachment hole  61  that is located at a top part of a door trim  60 . The rim  51  is designed in accordance with a design of the door trim  60 .  
         [0026]     As shown in  FIGS. 2, 4  and  6 , an integral combination of the lamp unit  20  and the light guide  30  is set in a door trim  60 . The design bezel  50  is downwardly inserted into the attachment hole  61  of the door trim  60 . Then, the rim  51  of the design bezel  50  engages the attachment hole  61  of the door trim  60 . Thus, the design bezel  50  is vertically fixed on the door trim  60  because a central axis  62  of the attachment hole  61  is vertical on the top part of the door trim  60 . Then, the design bezel  50  is inserted by the elongated portion  31  of the light guide  30  and fixed to the light guide  30  by hooks  35  of the light guide  30 . Thus, the integral combination and the design bezel  50  are engaged and attached to each other by the hooks  35  of the light guide  30 . Thus, the indicator lamp  10  is vertically fixed in the door trim  60 . Because the cover portion  32  covers the LED lamp  21 , the light guide  30  deflects water when water comes down from the design bezel  50  or the light emitting end  34  of the light guide  30 . Therefore, the indicator lamp  10  is waterproof.  
       Second Exemplary Embodiment  
       [0027]     As shown in  FIGS. 10-12 , an indicator lamp  11  includes a design bezel  50 , a light guide  30  and a lamp unit  20  from the top. The indicator lamp  11  is fixed to a door trim  60 . The lamp unit  20  includes an LED lamp  21 , a circuit  24 , which includes a zener diode and a resistance, and a connector casing  27 , which includes lead frames  28  and connects with other connectors. The connector casing  27  includes engaging claws  26  to connect with the light guide  30 .  
         [0028]     The light guide  30  includes an elongated portion  31  and a cover portion  32 . The elongated portion  31  and the cover portion  32  are integrally formed from acrylic resin. The elongated portion  31  is formed in a cylindrical shape and includes a cavity  37  at a bottom end and a light emitting end  34  at a top end. The light emitting end  34  is formed in a plane face in this embodiment. The cavity  37 , which is shaped in a conic notch, receives a light from the LED lamp  21 . The bottom end of the elongated portion  31  can also be a plane face to receive the light from the LED lamp  21 . The elongated portion  31  of the light guide  30  introduces the light from the LED lamp  21  to the light emitting end  34 . Then, the light emitting end  34  emits the light from the LED lamp  21 . The light emitting end  34  can be finished with a light diffusing treatment. In this case, the light from the light emitting end  34  is well diffused and observed in an equal illumination. The elongated portion  31  can be finished with a light reflecting treatment on a side wall of the elongated portion  31 . In this case, a light from the LED lamp  21  is well reflected in the elongated portion  31  and introduced to the light emitting end  34 .  
         [0029]     The cover portion  32  partially covers the lamp unit  20 . The cover portion  32  of the light guide  30  includes a hollow portion  39  and a protruding part  40 . The hollow portion  39  accommodates the LED lamp  21  and the circuit  24 . The protruding part  40 , which protrudes from the light guide  30 , fixes the indicator lamp  11  to the door trim  60  by a screw (not shown). The cover portion  32  also includes engaging holes  36  to connect with the engaging claws  26  of the lamp unit  20 . The engaging holes  36  locate in a lower part of the cover portion  32 , which is below the LED lamp  21 . Thus, the light guide  30  covers the LED lamp  21  at the hollow portion  39  and connects with the lamp unit  20  at the engaging holes  36 . Therefore, because water from the top of the light guide  30  does not reach the LED lamp  21 , the indicator lamp  11  is waterproof.  
         [0030]     Referring to  FIGS. 2 and 10 , the design bezel  50  is formed in a tubular shape. The design bezel  50  is inserted into an attachment hole  61 , which is formed in a top part of the door trim  60 , from the above of the door trim  60 . The design bezel  50  includes a rim  51  at a top end of the design bezel  50 . The rim  51  is designed in accordance with a design of the door trim  60 . The rim  51  engages the attachment hole  61  of the door trim  60 . The design bezel  50  is vertically fixed to the door trim  60  because the central axis  62  of the attachment hole  61  is vertical. The design bezel  50  is also fixed to an inner wall of the door trim  60  by a supporter  52 . Thus, the design bezel  50  is vertically and stably fixed to the door trim  60  by the rim  51  and the supporter  52 .  
         [0031]     The lamp unit  20  is connected with the light guide  30  by the engaging claws  26 . Then, the elongated portion  31  of the light guide  30  is inserted into the design bezel  50 . The light emitting face  34  of the elongated portion  31  is exposed at the attachment hole  61  of the door trim  60 . Thus, the light from the LED lamp  21  can be observed at the door trim  60 . The protruding part  40  of the light guide  30  is fixed to the door trim  60  by the screw. Thus, the indicator lamp  11  is completely attached to the door trim  60 . When water comes down from the top of the indicator lamp  11 , the water does not reach the LED lamp  21  because the cover portion  32  of the light guide  30  covers the LED lamp  21  and the light guide  30  connects with the lamp unit  20  below the LED lamp  21 .  
         [0032]     The present invention is not limited to the above-mentioned exemplary embodiments. The engaging claws  26  can be formed on the light guide  30 . The indicator lamp  10 ,  11  can be attached in a passenger seat or an instrument panel of a vehicle.  
         [0033]     This disclosure is intended to explain how to fashion and use various embodiments in accordance with the invention rather than to limit the true, intended, and fair scope and spirit thereof. The foregoing description is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application, and to enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims, as may be amended during the pendency of this application for patent, and all equivalents thereof, when interpreted in accordance with the breadth to which they are fairly,. legally, and equitably entitled.

Technology Category: 7