Abstract:
A light-guide device is provided for detecting and amplify the light emitted by indicator lamps of functional modules mounted in a chassis. The light-guide device includes a plurality of light-guide columns, a circuit board, and a plurality of light-guide blocks. The circuit board includes a plurality of amplifying circuits, each including a photosensitive diode and a plurality of light-emitting diodes (LEDs). One of the LEDs is lit when the photosensitive diode detecting the light emitted by the indicator lamp of one corresponding functional modules. The light-guide blocks guide lights emitted by the corresponding LEDs to an outside of the chassis.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to a light-guide device and a mounting assembly using the light-guide device. 
         [0003]    2. Description of the Related Art 
         [0004]    Electronic apparatus often include a chassis and a plurality of functional modules mounted in the chassis. These functional modules are usually equipped with indicator lamps to show current working status of the corresponding functional modules. If the indicator lamps are disposed inside the chassis, light-guide columns are used to guide the light emitted by the indicator lamps to outside the chassis. However, after being guided over such distances, the intensity of the light is significantly reduced and the light becomes hard to see. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is an exploded, isometric view of an embodiment of an mounting assembly and a plurality of functional modules, the mounting assembly comprising a chassis, a plurality of mounting brackets, a front bezel, and a light-guide device including a circuit board. 
           [0006]      FIG. 2  is similar to  FIG. 1 , but showing a different perspective. 
           [0007]      FIG. 3  is an assembled, isometric view of  FIG. 1 . 
           [0008]      FIG. 4  is an exploded, isometric view of one of the mounting brackets and one of the functional module of  FIG. 1 . 
           [0009]      FIG. 5  is a circuit diagram of the circuit board of  FIG. 1 . 
           [0010]      FIG. 6  is an enlarged view of the circuit board of  FIG. 1 . 
           [0011]      FIG. 7  is an enlarged view of the circuit board of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Referring to  FIGS. 1 to 4 , an embodiment of a mounting assembly  50  is provided to mount a plurality of functional modules  60  therein. The mounting assembly  50  includes a chassis  800 , a plurality of mounting brackets  100 , a light-guide device  200 , and a front bezel  300  attached to the chassis  800 . Each of the functional modules  60  is equipped with an indicator lamp  62  embedded in a rear end thereof. Two threaded holes  64  are defined in each of opposite sidewalls of each of the functional modules  60 . 
         [0013]    Referring to  FIG. 4 , the mounting bracket  100  includes an end retainer  110 , a first side plate  120 , and a second side plate  130 . The end retainer  110  defines two threaded holes  111 , and a through hole  112 . A connecting tab  140  perpendicularly extends from each of the first side plate  120  and the second side plate  130 . The connecting tab  140  defines a mounting hole  142 . The first side plate  120  and the second side plate  130  each define two mounting holes  150  corresponding to the threaded holes  64  of the functional module  60 . A groove  122  is longitudinally defined through an inner side of the first side plate  120 , corresponding to the through hole  112  of the end retainer  110 . 
         [0014]    The front bezel  300  defines a plurality of mounting holes  310 . Two inner threaded post  320  extend from an inner side of the front bezel  300 . The front bezel  300  forms a plurality of locking portion (not shown) to retain the front bezel  300  to the chassis  800 . 
         [0015]    The light-guide device  200  includes a light-guide column  210  to be engaged in the groove  122  of the first side plate  120  of each mounting bracket  100 , a circuit board  220 , and a light-guide block  230  to be engaged in each mounting hole  310  of the front bezel  300 . 
         [0016]    Referring to  FIGS. 5 and 6 , the circuit board  220  defines two mounting holes  222  correspondingly adjacent to two opposite ends of the circuit board  220 , and includes a plurality of amplifying circuits  10  each corresponding to one functional module  60 . A connector  224  is positioned on a first side  223  of the circuit board  220 . In one embodiment, the connector  224  is a universal serial bus connector, which includes a power terminal VCC, a ground terminal GND, and two signal terminals USB-P, USB-N. The signal terminals USB-P and USB-N are two idle pins, and the ground terminal GND is grounded. The connector  224  is electrically coupled to a motherboard (not shown) in the chassis  800  to transfer power for the amplifying circuit  10 . 
         [0017]    Referring to  FIGS. 5-7 , each amplifying circuit  10  includes a plurality of light-emitting diodes (LEDs) D 1  disposed on the first side  223  of the circuit board  220 , a photosensitive diode D 2  disposed on a second side  225  of the circuit board  220  opposite to the first side  223 , an electronic switch, and resistors R 1 -R 3 . In one embodiment, the quantity of the LEDs D 1  of each amplifying circuit  10  is five, and the electronic switch is a transistor Q. In other embodiments, the quantity may vary. The cathode of the photosensitive diode D 2  is connected to the power terminal VCC of the connector  224  via the resistor R 1 . The anode of the photosensitive diode D 2  is grounded via the resistor R 2 . The LEDs D 1  of each amplifying circuit  10  are connected in parallel. The anodes of the LEDs D 1  are connected to the power terminal VCC via the resistor R 3 , and the cathodes of the LEDs D 1  are connected to the collector of the transistor G. The base of the transistor G is connected to the anode of the photosensitive diode D 2 . The emitter of the transistor G is grounded. 
         [0018]    Referring to  FIG. 4 , in assembling one of the functional modules  60  to the corresponding mounting bracket  100 , the first side plate  120  and the second side plate  130  of the mounting bracket  100  are connected to the end retainer  110  of the mounting bracket  100 , correspondingly adjacent to two opposite ends of the end retainer  110 , with two fasteners  144  such as screws, correspondingly passing through the mounting holes  142  of the first and second side plates  120 ,  130 , and engaging into the threaded holes  111  of the end retainer  110 . The groove  122  of the first side plate  120  is aligned with the through hole  112  of the end retainer  110 . The light-guide column  210  is received in the groove  122  of the first side plate  120  of the mounting bracket  100 , and a first end of the light-guide column  210  extends through the through hole  112  of the end retainer  110 . The functional module  60  is received in an accommodating space bounded by the first and second side plates  120 ,  130 , and the end retainer  110 , with the indicator lamp  62  opposite to the end retainer  110 . Four fasteners  146 , such as screws, correspondingly extend through the through holes  122  of the first and second side plates  120 ,  130 , and engage in the threaded holes  64  of the functional module  60 , to mount the functional module  60  in the mounting bracket  100 . At the same time, the light-guide column  210  is retained in the groove  122  of the first side plate  120 , with a second end of the light-guide column  210  adjacent to the indicator lamp  62  of the functional module  60 . Other mounting brackets  100  and functional modules  60  are assembled in the same way as described above. The assemblies of the mounting brackets  100  and the corresponding functional modules  60  are installed in the chassis  800  adjacent to a front end of the chassis  800 . Two screws  226  extend through the mounting holes  222  of the circuit board  220  and engage in the corresponding posts  320  of the front bezel  300  to retain the circuit board  220  to the rear side of the front bezel  300 , with the first side  223  of the circuit board  220  facing the front bezel  300 . The light-guide blocks  230  are engaged in corresponding mounting holes  310  of the front bezel  300 , and abutting corresponding LEDs D 1  of the circuit board  220 . The front bezel  300  is attached to the front end of the chassis  800 , with the second photosensitive diodes D 2  abutting the first ends of the light-guide columns  210 . 
         [0019]    During operation, if the indicator lamp  62  of one of the functional module  60  is not lit, no light is detected by the corresponding photosensitive diode D 2 . Therefore, the photosensitive diode D 2  is not conductive, and the base of the transistors Q is at a low voltage level. The transistor Q is turned off, and the LEDs D 1  are not lit. If the indicator lamp  62  of one of the functional modules  60  is lit, the light of the indicator lamp  62  is guided by the light-guide column and is detected by the photosensitive diode D 2 . The photosensitive diode D 2  is conductive, and the base of the transistor Q is at a high voltage level. The transistor Q is turned on, therefore the LEDs D 1  are lit. The light of the LEDs D 1  are guided by the corresponding light-guide block  230  to the front side of the front bezel  300  to be easily read. 
         [0020]    It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the description or sacrificing all of its material advantages, the examples hereinbefore described merely being exemplary embodiments.