Abstract:
The present disclosure discloses a lighting apparatus using a PN junction light-emitting element, the apparatus comprising: a power transmitting substrate; PN junction light-emitting elements mounted on the power transmitting substrate; circuit elements mounted on the power transmitting substrate and controlling power provided to the PN junction light-emitting elements; and a top cover covering the circuit elements and forward reflecting light emitted by the PN junction light-emitting elements.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit and priority of Korean patent Application No. KR-10-2011-0016995, filed Feb. 25, 2011. The entire disclosure of the above application is incorporated herein by reference. 
     FIELD 
     The present disclosure, in general, relates to a lighting apparatus using a PN junction light-emitting element, and more particularly, to a lighting apparatus using a PN junction light-emitting element that is slim and lightweight and easy to install on another object. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     In a lighting apparatus using a PN junction light-emitting element, a light-emitting diode (LED) module having a plurality of LEDs mounted on a power transmitting substrate is typically used as a light source. The LEDs have the advantages of small size, low power consumption and excellent control characteristics, and therefore the LED lighting apparatus can be made slim and lightweight. However, a typical LED lighting apparatus includes a heat sink for heat dissipation or a separate drive circuit for driving an LED module. Elements such as the heat sink or the drive circuit make it difficult to realize a slim and lightweight design of the LED lighting apparatus. 
     For example, the drive circuit may include an A/D converter to supply DC power, and the A/D converter includes a trans-coil for lowering the voltage of AC. The trans-coil has a drawback in that, since the trans-coil is arranged occupying a large space in the drive circuit, the dimension of the product having the same becomes large. 
     Meanwhile, since the LED module includes a plurality of LEDs, the overall current capacity becomes large. Thus, the conventional LED drive circuit employs an electrolytic capacitor as a part. Such an electrolytic capacitor is suitable for a circuit with high capacitance, but its poor frequency characteristics and relatively high aging degradation reduce the reliability of the circuit. Particularly, in the case of an electrolytic capacitor being mounted, together with an LED, on a power transmitting substrate, the lifespan of the electrolytic capacitor is much shortened due to heat generated by light emission of the LED. Additionally, as the volume of an inductor and a capacitor increases in a circuit having a plurality of LEDs arranged thereon, this may even cause limitations to the exterior design of an LED lighting apparatus. 
     Moreover, the outer appearance of a lighting apparatus generally varies according to general classification of lamps, such as an incandescent lamp type and a fluorescent lamp type, and has various shapes according to use and place. Accordingly, the shapes of an LED module, a heat sink and a drive substrate also vary with such various shapes. In addition, lighting apparatuses of various shapes are each provided depending on a specific installation environment. Due to this, the lighting apparatus becomes less compatible according to use and place and its installation becomes difficult. 
     SUMMARY 
     This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features. 
     According to one aspect of the present disclosure, there is provided a lighting apparatus using a PN junction light-emitting element, the apparatus including: a power transmitting substrate; PN junction light-emitting elements mounted on the power transmitting substrate; a bottom cover positioned under the power transmitting substrate; a top cover positioned over the power transmitting substrate and having openings exposing the PN junction light-emitting elements; and a transparent window positioned over the top cover. 
     According to another aspect of the present disclosure, there is provided a lighting apparatus using a PN junction light-emitting element, the apparatus including: a power transmitting substrate; PN junction light-emitting elements mounted on the power transmitting substrate; a casing housing the power transmitting substrate in a manner that the PN junction light-emitting elements can be seen; a transparent window that is coupled to the casing over the power transmitting substrate; and a bracket that is coupled to the casing and securing the casing to another object. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a view showing an example of a lighting apparatus using a PN junction light-emitting element according to the present disclosure. 
         FIG. 2  is a view showing an example of electrical connection between a power transmitting substrate and PN junction light-emitting elements. 
         FIG. 3  is a view showing an example of the configuration of a switch of  FIG. 2 . 
         FIG. 4  is a view showing the front surface of the lighting apparatus using the PN junction light-emitting element of  FIG. 1 . 
         FIG. 5  is a sectional view taken along line I-I′ of  FIG. 4 . 
         FIG. 6  is a view showing the front and rear surfaces of the lighting apparatus using the PN junction light-emitting element. 
         FIG. 7  is a view showing another example of the lighting apparatus using the PN junction light-emitting element according to the present disclosure. 
         FIG. 8  is a view showing the outer appearance of the lighting apparatus using the PN junction light-emitting element of  FIG. 7 . 
         FIG. 9  is a view showing a bracket, PN junction light-emitting elements and a top cover of  FIG. 7 . 
         FIG. 10  is a sectional view taken along line II-II′ of  FIG. 8 . 
         FIG. 11  is a view showing a lamp having a plurality of lighting apparatuses using a PN junction light-emitting element being installed in a lighting fixture. 
         FIG. 12  is a view showing the front surface of the lamp of  FIG. 11 . 
         FIG. 13  is a view showing still another example of the lighting apparatus using the PN junction light-emitting element according to the present disclosure. 
         FIG. 14  a view showing a lamp having a lighting apparatus using a PN junction light-emitting element of  FIG. 13  being installed on a rail. 
         FIG. 15  is a view showing the lamp of  FIG. 14  from a different angle. 
         FIG. 16  is a view showing a further example of the lighting apparatus using the PN junction light-emitting element according to the present disclosure. 
         FIG. 17  is a sectional view taken along line III-III′ of  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure will now be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a view showing an example of a lighting apparatus using a PN junction light-emitting element according to the present disclosure. 
     The lighting apparatus  5  using the PN junction light-emitting element includes a power transmitting substrate  21 , PN junction light-emitting elements  15 , a bottom cover  30 , a top cover  50 , and a transparent window  70 . 
     The PN junction light-emitting elements  15  are mounted over the power transmitting substrate  21 , and the power transmitting substrate  21  is housed between the bottom cover  30  and the top cover  50 . Openings  55  for exposing the PN junction light-emitting elements  15  are formed in the top cover  50 . The transparent window  70  is coupled to the top cover  50  and transmits light coming from the PN junction light-emitting elements  15 . The lighting apparatus  5  using the PN junction light-emitting element has the advantage of being slim and lightweight because there is no need to use a heat sink and a drive substrate for driving the PN junction light-emitting elements  15 . 
     Hereinafter, the lighting apparatus  5  using the PN junction light-emitting element will be described in detail, and the lighting apparatus  5  using the PN junction light-emitting element will be referred to as the lighting apparatus  5  for convenience of description. 
     The power transmitting substrate  21  receives power from an external source and supplies it to the PN junction light-emitting elements  15 . The power transmitting substrate  21  may be a printed circuit board. The power transmitting substrate  21  may include a metal layer for heat dissipation, a wiring layer, a connector  23 , and circuit elements  25 . The wiring layer is formed on the metal layer and may include wiring and an insulating layer for insulating the wiring. The power transmitting substrate  21  may have various shapes, including a disc, a rectangular plate, a linear rod, etc. according to applications of the lighting apparatus  5 . 
     As shown in  FIG. 1 , the connector  23  may be provided on each of the opposite short-side peripheries of the power transmitting substrate  21  of an approximately rectangular shape and receives power from an external source. A connection cable  40  is coupled to the connector  23  to apply transmitted power thereto. A plurality of lighting apparatuses  10  using a PN junction light-emitting element may be electrically connected to each other via the connection cable  40 . 
     The circuit elements  25  are provided on the power transmitting substrate  21 . The circuit elements  25  may be elements associated with power control. The shape and arrangement of the circuit elements  25  shown in  FIG. 1  are illustrated for convenience of description, so that the circuit elements  25  can be provided over the power transmitting substrate  21  in various configurations.  FIG. 1  shows a plurality of circuit elements as a typical example of the circuit elements  25 . As shown in  FIG. 1 , the circuit elements  25  may be positioned on peripheries of the power transmitting substrate  21 , i.e., in the vicinity of the PN junction light-emitting elements  15 . The circuit elements  25  are of a simple configuration and are suitable to be incorporated with the PN junction light-emitting elements  15  on the power transmitting substrate  21 . Preferably, the circuit elements  25  do not include an electrolytic capacitor having low heat resistance. 
     Unexplained reference numerals of  FIG. 1  will be described later in this disclosure. 
       FIG. 2  is a view showing an example of electrical connection between the power transmitting substrate and the PN junction light-emitting elements.  FIG. 3  is a view showing an example of the configuration of a switch of  FIG. 2 . 
     In an example of the circuit element  25 , as shown in  FIG. 2 , a bridge rectifying circuit  61  is used to drive the PN junction light-emitting elements  15  by AC, i.e., by sine wave power  2 . Accordingly, a heavy, large-volume element, such as an A/D converter, is not required to cause the PN junction light-emitting elements  15  to emit light. 
     Further, in an example of the circuit element  25 , as shown in  FIG. 2 , in a circuit having a plurality of PN junction light-emitting elements  15  connected in series, switches  63  can be used to drive the PN junction light-emitting elements  15 , while offering as wide a range of variation in input voltage as possible, by allowing electric current to flow even at a low input voltage, where the switches  63  cause as many PN junction light-emitting elements  15  as possible to emit light and short the remaining PN junction light-emitting elements  15 . The switches  63  shown in  FIGS. 2 and 3  can be easily implemented by using an OP amp comparator OP 1  for sensing whether the magnitude of an AC voltage of a switching transistor T reaches a set value. 
     A typical example of the PN junction light-emitting element  15  is a light-emitting diode (LED), and another example thereof may include a laser diode (LD). The LED may include, for example, a light-emitting chip, a fixed frame for holding the light-emitting chip, and an input lead line and an output lead line electrically connected to wiring of the power transmitting substrate  21 . As shown in  FIG. 1 , the PN junction light-emitting elements  15  are mounted in an array on the power transmitting substrate  21 , thus configuring a PN junction light-emitting element module  10 . 
     The PN junction light-emitting element module  10  is disposed on the bottom cover  30 . The bottom cover  30  may be made of plastic, and, as shown in  FIG. 1 . the bottom cover  30  may have a receiving recess  31  into which the power transmitting substrate  21  is to be inserted. A screw fastening portion, for example, screw fastening holes  33  are formed at the corners of the bottom cover  30 . The metal layer of the power transmitting substrate  21  is in contact with the bottom cover  30 , and heat generated during the light emission of the PN junction light-emitting elements  15  is dissipated via the metal layer of the power transmitting substrate  21  and the bottom cover  30 . As set forth herein, the lighting apparatus  5  has significantly reduced volume and weight because it has no heat sink having a heat dissipation fin or heat radiation blade. To improve the heat dissipation characteristics, the bottom cover  30  may be made of heat dissipation plastic having excellent heat dissipation characteristics. Moreover, an excessive temperature rise can be suppressed by decreasing the number of PN junction light-emitting elements  15  mounted on the power transmitting substrate  21 . 
     Moreover, since the receiving recess  33  is formed in the bottom cover  30  as described above, the heat dissipation efficiency can be improved by a reduction in the thickness of the bottom cover  30 . 
       FIGS. 4   a  and  4   b  are views showing the front surface of the lighting apparatus using the PN junction light-emitting element of  FIG. 1 .  FIG. 5  is a sectional view taken along line I-I′ of  FIG. 4 . 
     The top cover  50  is positioned on the power transmitting substrate  21  and coupled to the bottom cover  30 . The top cover  50  may include a base portion  51 , a sloping portion  53 , and a side portion  56 . Openings  55  corresponding to the PN junction light-emitting elements  15  are formed in the base portion  51 . The PN junction light-emitting elements  15  may be exposed through the openings  55  as shown in  FIG. 4   a  and inserted into the openings  55  as shown in  FIG. 5 . The sloping portion  53  extends from an edge of the base portion  51 , and, as shown in  FIG. 5 , extends upward so as to form an angle of inclination with respect to the base portion  51 . The sloping portion  53  corresponds to a periphery of the power transmitting substrate  21 , and a space is defined between the power transmitting substrate  21  and the sloping portion  53  where the above-described circuit elements  25  are to be seated. The side portion  56  extends downward from the upper end of the sloping portion  53  and is coupled to the bottom cover  30 . For example, as shown in  FIG. 1 , a fastening protrusion  54  is provided on the side portion  56 , and the bottom cover  30  may have a fastening hole into which the fastening protrusion  54  is inserted in a hook coupling manner. The top cover  50  may have a screw fastening hole  57  corresponding to the bottom cover  30 . 
     The transparent window  70  is positioned over the top cover  50  as shown in  FIGS. 4   b  and  5 , and a guide slot in which the transparent window  70  is placed is formed in the upper end of the side portion  56  of the top cover  50 . The transparent window  70  shields and protects the PN junction light-emitting elements  15  from the outside. The transparent window  70  may be made of transparent plastic and may transmit light coming from the PN junction light-emitting elements  15  and adjust the orientation angle of the light. 
     As described above, the lighting apparatus  5  performs heat dissipation from the power transmitting substrate  21  to the bottom cover  30  without using a separate heat sink and realizes a compact coupling structure of the bottom cover  30 , the power transmitting substrate  21 , the top cover  50  and the transparent window  70  without including a separate drive circuit. Accordingly, it is possible to provide the slim and lightweight lighting apparatus  5 . 
       FIG. 6  is a view showing the front and rear surfaces of the lighting apparatus using the PN junction light-emitting element. 
     The lighting apparatus  5  may be installed in plural number in a lighting fixture by means of screws  96  as shown in  FIG. 6   a , or may be individually installed on a wall, a ceiling, etc. Alternatively, as shown in  FIG. 6   b , a magnet  94  may be provided on the rear surface of the bottom cover  30 , so that the lighting apparatus  5  can be attached to another object by the magnet  94 . Attaching the lighting apparatus  5  by the magnet  94  offers the advantage that the position of the lighting apparatus  5  can be easily changed as needed. 
       FIG. 7  is a view showing another example of the lighting apparatus using the PN junction light-emitting element according to the present disclosure.  FIG. 8  is a view showing the outer appearance of the lighting apparatus using the PN junction light-emitting element of  FIG. 7 . 
     The lighting apparatus  505  using a PN junction light-emitting element includes a power transmitting substrate  21 , PN junction light-emitting elements  15 , a bottom cover  30 , a top cover  50 , a transparent window  70 , and a bracket  90 . 
     The lighting apparatus  505  is substantially identical to the lighting apparatus  5  using a PN junction light-emitting element explained with reference to  FIGS. 1 to 6  except that a fastening slot  59  is formed in the top cover  50  and a bracket  90  is further included. Accordingly, like components are given like reference numerals, and duplicate description thereof will be omitted. 
     As shown in  FIGS. 7 and 8 , the bottom cover  30  and the top cover  50  are coupled to form a casing  7 . The power transmitting substrate  21  on which the PN junction light-emitting elements  15  are mounted is housed in the casing  7 . 
     The bracket  90  is coupled to the casing  7  and secures the casing  7  to another object, such as a lighting fixture. The bracket  90  will be described later in detail. 
       FIG. 9  is a view showing the bracket, PN junction light-emitting elements, and top cover of  FIG. 7 .  FIG. 10  is a sectional view taken along line II-II′ of  FIG. 8 . 
     The top cover  50  is positioned over the power transmitting substrate  21  and coupled to the bottom cover  30 . The top cover  50  may include, as shown in  FIG. 10 , a base portion  51 , a sloping portion  53 , and a side portion  56 . 
     Fastening slots  59  for fastening the bracket  90  may be formed in the four corner sides of the side portion  56  as shown in  FIG. 7 . The bracket  90  may be made of metal or plastic. The bracket  90  includes, for example, a main body  91 , a first coupling portion  93 , and a second coupling portion  95 . 
     As shown in  FIGS. 7 ,  8  and  10 , the main body  91  may be positioned on the rear surface of the bottom cover  30 . The first coupling portion  93  is, for example, a hook  93  that extends from the main body  91  and is coupled to a fastening slot  59  formed in the side portion  56  of the top cover  50 . Four first coupling portions  93  extend from near the four corners of the long-side edges of the main body  91 . The height from the rear surface of the bottom cover  30  to the fastening slot  59  is greater than the height of the hook  93 , so that the hook  93  can be press-fitted into the fastening slot  59 . 
     The second coupling portions  95  may extend from the long-side edges of the main body  91  so as to be exposed to the sides of the bottom cover  30 . In order to install a plurality of casings  7  in a compact manner, as shown in  FIG. 9 , it is preferable that the second coupling portions  95  should be formed at staggered positions on the opposite long sides of the main body  91 . A bracket fixing hole  97  is elongated in the second coupling portion  95  as shown in  FIGS. 7 and 9 , thus making it possible to relatively freely select a fastening position. With the second coupling portion  95  being formed in a staggered manner on the opposite sides of the main body  91  and the bracket fixing hole  97  being longitudinally formed, the installation of the lighting apparatus is made easy. 
     The shape of the bracket  90  may be different from the aforementioned one. For example, the bracket  90  may be formed in the shape of a chassis in which the main body  91  corresponds not to the entire rear surface of the bottom cover  30  but only to the periphery of the rear surface of the bottom cover  30 , and the shapes of the first coupling portion  93  and the second coupling portion  95  may be changed in various ways. 
     The above-described lighting apparatus  505  may be implemented as a single lighting apparatus or implemented in an array in plural number. 
       FIG. 11  is a view showing a lamp having a plurality of lighting apparatuses using a PN junction light-emitting element being installed in a lighting fixture.  FIG. 12  is a view showing the front surface of the lamp of  FIG. 11 . 
     The lighting fixture  101  is a kind of lighting fixture used for various purposes, such as a streetlight or an interior light. The lighting fixture  101  may include a lighting fixture body  110  and a light transmissive front cover  130 . As shown in  FIGS. 11 and 12 , the plurality of lighting apparatuses  505  are installed in the lighting fixture body  110 . As discussed above, the connectors of the plurality of lighting apparatuses  505  are electrically connected to each other via a connection cable  40 , and an electrical connection method of the plurality of lighting apparatuses  505  can be easily changed depending on how the connection cable  40  is to be connected. 
     The second coupling portions  95  of the neighboring brackets  90  are installed in a staggered manner as shown in  FIG. 12 , thereby enabling it to install the neighboring lighting apparatuses  505  in a compact manner. Since the bracket fixing hole  97  formed in the second coupling portion  95  is elongated, a screw fastening position can be selected as desired in the bracket fixing hole  97 . Moreover, the lighting fixture  101  can be configured to be slim and lightweight because the lighting apparatus  505  is slim and lightweight as described above, and various kinds of lamps can be easily configured by varying the number and array of the lighting apparatuses  505 . 
       FIGS. 13   a  and  13   b  are views showing still another example of the lighting apparatus using the PN junction light-emitting element according to the present disclosure.  FIG. 14  a view showing a lamp having a lighting apparatus using a PN junction light-emitting element of  FIG. 13  being installed on a rail.  FIG. 15  is a view showing the lamp of  FIG. 14  from a different angle. 
     A lighting apparatus  705  is substantially identical to the lighting apparatus  505  explained with reference to  FIGS. 7 to 12  except that it is a fluorescent lamp type elongated in one side and installed on a guide rail  701 , and a bracket  790  has a different shape. Accordingly, like components are given like reference numerals, and duplicate description thereof will be omitted. 
     PN junction light-emitting elements  715  are longitudinally arrayed in a row on a power transmitting substrate (not shown) and configured in a fluorescent lamp type. The power transmitting substrate is housed in a casing  707  which is composed of a bottom cover  730  and a top cover  750 . Openings corresponding to the PN junction light-emitting elements  715  are formed in a top cover  750 . A transparent window  770  is coupled to the top cover  750 . 
     As discussed earlier, it is preferable that heat should be dissipated directly via the bottom cover  730  from the power transmitting substrate without using a separate heat sink and that the power transmitting substrate should not have an electrolytic capacitor. 
     The bracket  790  is coupled to the bottom cover  730  and secures the casing  707  to the guide rail  701 . 
     The guide rail  701  may be installed on a ceiling or wall or outdoors, and one or more lighting apparatuses  705  may be installed on the guide rail  701 . 
     A first coupling portion (not shown) of the bracket  790  may be protruded from a main body  791  and fastened to a slot formed in the rear surface of the bottom cover  730 . 
     A second coupling portion  795  is, for example, a slider  795  coupled to the guide rail  701  as shown in  FIG. 15 . The slider  795  is movable along the guide rail  701 . Alternatively, a stopper (not shown) may be installed on the slider  795  or the casing  707  so as to be secured at a desired position of the guide rail  701 . Otherwise, the slider  795  may be coupled and fixed to the guide rail  701 . Since the guide rail  701  is installed in a desired location and one or more lighting apparatuses  705  are easily installed on the guide rail  701  by the bracket  790 , the lamp can be of various configurations and be easily installed. 
       FIG. 16  is a view showing a further example of the lighting apparatus using the PN junction light-emitting element according to the present disclosure. FIG.  17  is a sectional view taken along line III-III′ of  FIG. 16 . 
     The lighting apparatus  205  is substantially identical to the lighting apparatus  5  explained with reference to  FIGS. 1 to 6  except that it has a circular shape. Accordingly, like components are given like reference numerals, and duplicate description thereof will be omitted. 
     The power transmitting substrate  221  has a disc shape, and, as shown in  FIG. 17 , is housed between the bottom cover  230  and the top cover  250 . The PN junction light-emitting elements  215  are arranged in a circular pattern as shown in  FIG. 16(   a ). Circuit elements  226  are disposed on the periphery of the power transmitting substrate  221  as shown in  FIG. 17 , a sloping portion  253  of the top cover  250  corresponds to the periphery of the power transmitting substrate  221 , and the circuit elements  226  are positioned under the sloping portion  253 . 
     The PN junction light-emitting elements  215  may be three-chip PN junction light-emitting elements, each having three chips packaged therein, and can change the light amount by changing the chip size. 
     Hereinafter, various exemplary embodiments of the present disclosure will be described. 
     (1) A lighting apparatus using a PN junction light-emitting element, wherein a top cover includes: a base portion having openings into which the PN junction light-emitting elements are to be inserted; and a sloping portion extending from the base portion and spaced apart from a power transmitting substrate. 
     (2) A lighting apparatus using a PN junction light-emitting element, wherein a power transmitting substrate includes: a connector into which external power is input; and circuit elements positioned under the sloping portion and associated with power control. 
     (3) A lighting apparatus using a PN junction light-emitting element, wherein a power transmitting substrate does not include an electrolytic capacitor as a circuit element. 
     (4) A lighting apparatus using a PN junction light-emitting element, wherein a circuit element includes: a bridge rectifying circuit for rectifying AC to drive the PN junction light-emitting elements; and at least one switch, which is connected to at least one of the plurality of PN junction light-emitting elements connected in series, allows electric current to flow even when an input voltage is lower than the voltage causing the entire PN junction light-emitting elements connected in series to emit light, thereby causing as many PN junction light-emitting elements as possible to emit light, and bypasses the remaining PN junction light-emitting elements. 
     As the methods of driving the PN junction light-emitting elements by AC, various driving methods utilizing pulsating current, as well as the above method using the circuit elements, can be employed. Additionally, the lighting apparatus using the PN junction light-emitting element according to the present disclosure employs both the method of driving the PN junction light-emitting elements by AC without having circuit elements provided on the power transmitting substrate and the method of disposing the PN junction light-emitting elements in both directions and driving them by AC power without using a bridge rectifying circuit. Besides, various methods of driving the PN junction light-emitting elements may be applied to the configuration of the power transmitting substrate. For instance, a drive circuit using switching mode power supply (SMPS) may be provided on the power transmitting substrate. 
     (5) A lighting apparatus using a PN junction light-emitting element, wherein the bottom cover is made of plastic and has a receiving recess into which the power transmitting substrate is to be inserted. 
     While the bottom cover may be made of plastic to reduce the weight, the bottom cover may be made of metal to improve heat dissipation efficiency. 
     (6) A lighting apparatus using a PN junction light-emitting element, wherein a power transmitting substrate includes: a metal layer brought into contact with the bottom cover; a wiring layer formed over the metal layer and electrically connected to the PN junction light-emitting elements; a connector provided on the wiring layer and receiving external power; and circuit elements positioned under a sloping portion and associated with power control. 
     The metal layer is an example of a configuration for improving heat dissipation efficiency, and various configurations may be applied to improve the heat dissipation characteristics of the power transmitting substrate. A heat dissipation tape, a heat dissipation sheet, etc. may be added between the power transmitting substrate and the bottom cover. 
     (7) A lighting apparatus using a PN junction light-emitting element, wherein the apparatus further includes a magnet provided on the rear surface of a bottom cover to secure the lighting apparatus using the PN junction light-emitting element to another object. 
     (8) A lighting apparatus using a PN junction light-emitting element, wherein the apparatus further includes a screw fastening portion provided on a bottom cover and a top cover to secure the lighting apparatus using the PN junction light-emitting elements to another object. 
     (9) A lighting apparatus using a PN junction light-emitting element, wherein the apparatus further includes a bracket having: a main body positioned on a bottom cover; a first coupling portion extending from the main body and coupled to a top cover; and a second coupling portion extending from the main body and securing the bottom cover and the top cover to another object. 
     The bracket may have various shapes. A bracket whose contact area with the rear surface of the casing is wide will be more advantageous for heat dissipation. When the bracket and the bottom cover are made of metal, the heat dissipation efficiency can be further improved. 
     (10) A lighting apparatus using a PN junction light-emitting element, wherein a casing includes: a bottom cover positioned under a power transmitting substrate and coupled to another object by a bracket; and a top cover that supports a transparent window, is coupled to the bottom cover, and has openings exposing the PN junction light-emitting elements toward the transparent window. 
     (11) A lighting apparatus using a PN junction light-emitting element, wherein a bracket includes: a main body positioned on a bottom cover; a first coupling portion extending from the main body and coupled to a casing; and a second coupling portion extending from the main body and securing the casing to another object. 
     (12) A lighting apparatus using a PN junction light-emitting element, wherein a first coupling portion includes a hook fastened to a slot formed in a top cover. 
     (13) A lighting apparatus using a PN junction light-emitting element, wherein a second coupling portion extends from the main body and has a bracket fixing hole to be fastened to another object. 
     (14) A lighting apparatus using a PN junction light-emitting element, wherein a bracket fixing hole is elongated so that a fastening position can be selected therein. 
     (15) A lighting apparatus using a PN junction light-emitting element, wherein a plurality of casings, each housing a power transmitting substrate, are installed in a lighting fixture by means of brackets, and second coupling portions of the neighboring brackets are placed in a staggered manner. 
     Lamps of various uses and sizes can be configured depending on the number and installation methods of lighting apparatuses using a PN junction light-emitting element in a lighting fixture. Various methods, such as screw fastening, hook fastening, etc., can be applied to the coupling of the brackets, the casings and the lighting fixture. 
     (16) A lighting apparatus using a PN junction light-emitting element, wherein second coupling portions extend from staggered positions of the opposite sides of a main body, respectively, are exposed to the opposite sides of the casing, respectively, and have a bracket fixing hole to be coupled to a lighting fixture. 
     (17) A lighting apparatus using a PN junction light-emitting element, wherein a power transmitting substrate includes a connector to which power is input, and the power transmitting substrates housed in a plurality of casings are electrically connected by a connection cable that interconnects the connectors. 
     (18) A lighting apparatus using a PN junction light-emitting element, wherein a second coupling portion includes a slider coupled to a guide rail. 
     The lighting apparatus using the PN junction light-emitting element according to the present disclosure allows a reduction in volume and weight because no heat sink is required. 
     In addition, a reduction in volume and weight is achieved because no separate drive substrate is required, other than the power transmitting substrate having the PN junction light-emitting elements mounted thereon. 
     Moreover, the circuit elements provided on the power transmitting substrate do not include an electrolytic capacitor having low resistance to heat, thereby preventing deterioration of reliability such as lifespan. 
     Further, it is possible to provide the slim and lightweight lighting apparatus using the PN junction light-emitting element because the bottom cover, the power transmitting substrate, the top cover and the transparent window have a compact coupling structure. 
     Furthermore, the lighting apparatus using the PN junction light-emitting element according to the present disclosure makes it possible to configure a lamp in various ways and makes installation easy because the lighting apparatus using the PN junction light-emitting element can be easily installed in the lighting fixture or on the rail by means of the bracket. 
     Still furthermore, it is possible to provide the slim and lightweight lighting apparatus using the PN junction light-emitting element because the bottom cover, the power transmitting substrate, the top cover, the transparent window and the bracket have a compact coupling structure. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.