Patent Publication Number: US-2007121312-A1

Title: Lighting device for display device used in vehicles

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      The application claims the benefit of Korea Patent Application No. 2005-113245 filed with the Korea Intellectual Property Office on Nov. 25, 2005, the disclosure of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a lighting device for display device used in vehicles. The lighting device can be applied to parts (for example, a dash board, an audio, a display device and the like), which are mounted on various vehicles such as cars, trains, ships, airplanes, helicopters and motorcycles and have a lighting function.  
      2. Description of the Related Art  
      Among display devices used in various vehicles, a dashboard used in cars is representative. In the dashboard, a simple color or a unified color is applied in accordance with a type of car. Recently, as an applied field of a light emitting diode (LED) for lighting is widened, the adoption of the LED as a lamp of cars gradually increases. Accordingly, the car lamp market puts down roots as one of important LED markets. Further, an existing display unit installed inside cars, which has had only a simple information display function, is developing into a multi-function display unit.  
       FIG. 1  is a plan view illustrating a car dashboard which emits light using a general lighting device.  
      In the car dashboard which informs a driver of a traveling state of a car through the operation of an indicator  10  on a graphic plate  30 , a direct lighting method is employed. In the direct lighting method, an incandescent lamp, a cold cathode tube, an electro luminescence plate, or an LED is used as a lighting source. Here, reference numeral  70  of  FIG. 1  represents an external case.  
      However, since the scattering of emitted light is severe, the incandescent lamp has non-uniform lighting performance, and the lifespan thereof is short. In a case where the cold cathode tube or electro luminescence plate is used instead of the incandescent lamp, more bright and uniform lighting can be obtained than when the incandescent lamp is used. However, the structure thereof is more complicated, the cost thereof is more expensive than the incandescent lamp or LED, and the lifespan thereof is short like the incandescent lamp.  
      Conventionally, as an LED is used as a lighting source of a car dashboard or the like, a semi-permanent lifespan and a lighting source with high luminance are obtained.  
       FIG. 2  is a sectional view illustrating a conventional lighting device for display device used in vehicles, the light device using the LED.  
      As shown in  FIG. 2 , the conventional lighting device for display device includes an indicator  10  provided with a rotating shaft  20 ; a graphic plate  30  disposed under the indicator  10  and having a through hole formed in the center thereof, into which the rotating shaft  20  is inserted; an LED  40  disposed under the graphic plate  30 ; a reflecting section  50  which reflects light generated by the LED  40  onto the graphic plate  30 ; and a motor  60  which is disposed on the rear surface of the graphic plate  30  and is connected to the rotating shaft  20  of the indicator  10  in order to support and drive the indicator  10 .  
      The conventional lighting device according to the related art is constructed so that light generated from the LED  40  fixed to the inside of the case  70  is directly illuminated onto the graphic plate  30 . In this case, the LED  40  is composed of one-color LED, and the reflecting section  50  reflects light generated from the LED  40  onto the graphic plate  30 , thereby enhancing a lighting effect of the LED  40 .  
      In the above-described lighting device for display device, however, the LED  40  as a lighting source is composed of one-color LED. Therefore, the LED can implement only a simple color, but cannot implement various colors in accordance with a user&#39;s taste.  
     SUMMARY OF THE INVENTION  
      An advantage of the present invention is that it provides a lighting device for display device used in vehicles, which is capable of implementing various colors in accordance with a user&#39;s taste by combining multiple colors of light.  
      Additional aspects and advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.  
      According to an aspect of the invention, a lighting device for display device used in vehicles includes an indicator provided with a rotating shaft; a graphic plate disposed under the indicator and having a through hole formed in the center thereof, into which the rotating shaft is inserted; and an LED section that is disposed under the graphic plate, generates light onto the graphic plate, and is provided with LED chips having different colors.  
      According to another aspect of the invention, the LED section is composed of more than two combinations of a group consisting of a red LED chip, a green LED chip, and a blue LED chip.  
      According to a further aspect of the invention, the LED section is provided with at least one LED unit which is composed of a combination of more than two chips selected from a group consisting of a red LED chip, a green LED chip, and a blue LED chip.  
      According to a still further aspect of the invention, the lighting device for display device further includes a reflecting section that reflects the light, generated by the LED section, onto the graphic plate. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:  
       FIG. 1  is a plan view illustrating a dash board which emits light using a general lighting device;  
       FIG. 2  is a sectional view of a conventional lighting device for display device used in vehicles;  
       FIG. 3  is a sectional view of a lighting device for display device used in vehicles according to the present invention; and  
       FIGS. 4 and 5  are plan views illustrating LED arrangements of the lighting device for display device according to an embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.  
      Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.  
       FIG. 3  is a sectional view of a lighting device for display device used in vehicles according to an embodiment of the invention.  
      As shown in  FIG. 3 , the lighting device for display device according to the embodiment of the invention includes an indicator  10  provided with a rotating shaft  20 ; a graphic plate  30  disposed under the indicator  10  and having a through hole formed in the center thereof, into which the rotating shaft  20  is inserted; and an LED section  40  which is disposed under the graphic plate  30 , generates light onto the graphic plate  30 , and is provided with LED chips having a different color. Further, on the rear surface of the graphic plate  30 , a motor  60  connected to the rotating shaft  20  of the indicator  10  is disposed so as to support and drive the indicator  10 .  
      The LED section  40  according to the embodiment of the invention is composed of a combination of red, green, and blue LED chips, different from the one-color LED according to the related art.  
       FIGS. 4 and 5  are plan views illustrating LED arrangements of the lighting device for display device according to the embodiment of the invention.  
      The LED section  40  is a lighting source used for the lighting device for display device according to the embodiment of the invention. As shown in  FIG. 4A , the LED section  40  may be composed of at least one LED unit U which is composed of a combination of a red LED chip  40 R, a green LED chip  40 G, and a blue LED chip  40 B.  
      Further, as shown in  FIG. 4B , the LED section  40  may be composed of at least one LED unit U which is composed of a combination of two chips selected from a group consisting of the red LED chip  40 R, the green LED chip  40 G, and the blue LED chip  40 B.  
      In other words, the LED section  40  may be provided with only one LED unit U or a plurality of LED units U, the LED unit U being composed of a combination of more than two chips selected from a group consisting of the red LED chip  40 R, the green LED chip  40 G, and the blue LED chip  40 B.  
      In addition, the LED section  40  may be composed of LED chips having a different color instead of the above-described LED unit U. That is, the LED section  40  may be composed of more than two combinations of a group consisting of the red LED chip  40 R, the green LED chip  40 G, and the blue LED chip  40 B. For example, more than one red LED chip  40 R, more than one green LED chip  40 G, and more than one blue LED chip  40 B, respectively, are combined to compose the LED section  40 , as shown in  FIG. 5A .  
      As shown in  FIG. 5B , the LED section  40  may be constructed by combining only two kinds of chips selected from a group consisting of the red LED chip  40 R, the green LED chip  40 G, and the blue LED chip  40 B.  
      As described above, the LED section  40  according to the embodiment of the invention may be provided with one LED unit U or a plurality of LED units U, the LED unit U being composed of a combination of more than two chips selected from a group consisting of the red LED chip  40 R, the green LED chip  40 G, and the blue LED chip  40 B. Alternately, the LED section  40  may be composed of more than two combinations of a group consisting of the red LED chip  40 R, the green LED chip  40 G, and the blue LED chip  40 B. In such a manner, the LED section  40  is provided with multiple-color LEDs.  
      The LED section  40  composed of the LED units U or the respective LED chips can emit monochromatic light using one color among three colors of the red LED chip  40 R, the green LED chip  40 G, and the blue LED chip  40 B. Further, the LED section  40  can emit various colors of light, including white color of light, by combining two kinds or three kinds of light.  
      According to the invention, a color of light emitted by the LED section  40  can be changed in accordance with the necessity, so that the lighting device for display device can illuminate various colors of light in accordance with a user&#39;s taste.  
      The lighting device according to the embodiment of the invention is constructed so that light generated from the LED section  40  fixed to the inside of the case  70  is directly illuminated onto the graphic plate  30 . Here, a reflecting section  50  may be additionally included in order to improve a lighting effect. The reflecting section  50  reflects the light generated by the LED section  40  onto the graphic plate  30 , thereby improving a lighting effect of the LED section  40 .  
      The above-described lighting device for display device used in vehicles can be applied to a direct lighting method, in which the LED section  40  is installed so as to face the rear surface of the graphic plate  30  as shown in  FIG. 3 , thereby directly generating light onto the graphic plate  30 . However, the lighting device can be also applied to an indirect lighting method, depending on a mounted position of the LED section  40 .  
      In the lighting device for display device used in vehicles according to the invention, the LED section implementing more than two kinds of different colors is used as a lighting source. Therefore, one-color light can be emitted, or various colors of light including a white color can be emitted by combining red, green, and blue in accordance with a user&#39;s taste.  
      Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.