Abstract:
A lighting apparatus comprises: a body comprising a first body and a second body, wherein the first body comprises a first bottom surface and a first side surface, wherein the second body comprises a second bottom surface and a second side surface, and wherein the body has a receiving recess configured by the first bottom surface, the second bottom surface, the first side surface and the second side surface; a reflector disposed in the receiving recess of the body and comprising a plurality of reflective surfaces; and a light source disposed on the first side surface of the first body and the second side surface of the second body, disposed at an area corresponding to the reflective surfaces of the reflector.

Description:
[0001]    This application is a Continuation Application of U.S. application Ser. No. 13/610,481 file Sep. 11, 2012, which a Continuation Application of U.S. application Ser. No. 13/206,224 filed Aug. 9, 2011, which claims priority from Korean Application Nos. 10-2010-0110472, 10-2010-0110478, 10-2010-0110561, 10-2010-0110562, and 10-2010-0110563, filed Nov. 8, 2010, the subject matters of which are incorporated herein by reference 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to a lighting apparatus. 
       BACKGROUND 
       [0003]    A light emitting diode (LED) is an energy device for converting electric energy into light energy. Compared with an electric bulb, the LED has higher conversion efficiency, lower power consumption and a longer life span. As there advantages are widely known, more and more attentions are now paid to a lighting apparatus using the LED. 
         [0004]    The lighting apparatus using the LED are generally classified into a direct lighting apparatus and an indirect lighting apparatus. The direct lighting apparatus emits light emitted from the LED without changing the path of the light. The indirect lighting apparatus emits light emitted from the LED by changing the path of the light through reflecting means and so on. Compared with the direct lighting apparatus, the indirect lighting apparatus mitigates to some degree the intensified light emitted from the LED and protects the eyes of users. 
       SUMMARY 
       [0005]    One embodiment is a lighting apparatus. The lighting apparatus comprises: a body comprising a first body and a second body, wherein the first body comprises a first bottom surface and a first side surface, wherein the second body comprises a second bottom surface and a second side surface, and wherein the body has a receiving recess configured by the first bottom surface, the second bottom surface, the first side surface and the second side surface; a reflector disposed in the receiving recess of the body and comprising a plurality of reflective surfaces; and a light source disposed on the first side surface of the first body and the second side surface of the second body, disposed at an area corresponding to the reflective surfaces of the reflector. 
         [0006]    Another embodiment is a lighting apparatus. The lighting apparatus comprises: a body comprising a bottom surface and a side surface; a reflector disposed on the bottom surface of the body and comprising a first a reflective surface and a second reflective surface; a light source disposed on the side surface of the body, comprising a first light source disposed on the first reflective surface and a second light source disposed on the second reflective surface; and a connection board disposed on the side surface of the body, electrically connecting between the first light source and the second light source. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of a lighting apparatus according to an embodiment of the present disclosure. 
           [0008]      FIG. 2  is an exploded perspective view of the lighting apparatus shown in  FIG. 1 . 
           [0009]      FIG. 3  shows an exploded perspective view and a perspective view of coupling the body of the lighting apparatus shown in  FIG. 2 . 
           [0010]      FIG. 4  is an exploded perspective view of the light source of the lighting apparatus shown in  FIG. 2 . 
           [0011]      FIG. 5  is a perspective view for describing the relation between the reflector and the lens which are shown in  FIG. 2 . 
           [0012]      FIG. 6  is a perspective view showing other embodiments of the reflector shown in  FIG. 2 . 
           [0013]      FIG. 7  shows the top and bottom perspective views of the connection board shown in  FIG. 2 . 
           [0014]      FIG. 8  is an exploded perspective view for describing another embodiment of the connection board of the lighting apparatus shown in  FIG. 2 . 
           [0015]      FIG. 9  is a perspective view of the cover of the lighting apparatus shown in  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0016]    In the drawings, a thickness or size of each layer may be magnified, omitted or schematically shown, simply for purpose of convenience and clarity of description. The size of each component may not necessarily represent its actual size. 
         [0017]    Further, when an element is referred to as being ‘on’ or “under” another element, it may be directly on/under the element, or one or more intervening elements may also be present. When an element is referred to as being ‘on’ or ‘under’, ‘under the element’ as well as ‘on the element’ may be included based on the element. 
         [0018]    Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. 
         [0019]      FIG. 1  is a perspective view of a lighting apparatus according to an embodiment of the present disclosure.  FIG. 2  is an exploded perspective view of the lighting apparatus shown in  FIG. 1 . 
         [0020]    Referring to  FIGS. 1 and 2 , a lighting apparatus according to an embodiment of the present disclosure includes a body  110 , a light source  120 , a reflector  130 , a connection board  140 , a cover  150 , an optic plate  160  and an optic plate holder  170 . Hereafter, the components will be described in detail with reference to the drawings. 
         [0021]      FIG. 3  shows an exploded perspective view and a perspective view of coupling the body of the lighting apparatus shown in  FIG. 2 . 
         [0022]    The body  110  is formed by combining at least two parts. For example, as shown in  FIG. 3 , the body  110  is formed by combining a first body  110 -A with a second body  110 -B. Through the combination of the at least two parts, when a lighting apparatus is assembled according to the embodiment of the present disclosure, the light source  120  and the reflector  130  can be easily installed in a receiving recess  115  of the body  110 . 
         [0023]    The body  110  includes the receiving recess  115  for receiving the light source  120  and the reflector  130 . Here, the receiving recess  115  is configured by a side surface  111  and a bottom surface  113 . Here, the recess of the receiving recess  115  includes a cavity and a groove. 
         [0024]    The side surface  111  of the body  110  is equipped with the light source  120 . In more detail, referring to  FIG. 2 , the side surface  111  of the body  110  comes in surface contact with the one side of a substrate  121  of the light source  120 . Since the side surface  111  of the body  110  is equipped with the light source  120 , the body  110  can easily receive heat from the light source  120 . 
         [0025]    The reflector  130  is mounted on the bottom surface  113  of the body  110 . 
         [0026]    The side surface  111  of the body  110  may be a predeterminedly curved or may not be curved, for example, a polygonal pillar. When the side surface  111  of the body  110  is curved, a portion on which a substrate  121  is placed on the side surface  111  of the body  110  is flat. Otherwise, the side surface  111  of the body  110  includes, as shown in  FIG. 3 , an mounting recess  117  into which the substrate  121  of the light source  120  is inserted, and the bottom surface of the mounting recess  117  is flat. Since the side surface  111  of the body  110  includes the mounting recess  117 , the side surface  111  of the body  110  also comes in surface contact with the lateral surface of the substrate  121  of the light source  120 . Therefore, the body  110  can receive more easily the heat from the light source  120 . Further, the substrate  121  of the light source  120  can be easily mounted on the inner surface of the body  110 . Here, the recess of the mounting recess  117  includes a cavity and a groove. 
         [0027]    The body  110  receives the heat from the light source  120  and retains or radiates the heat to the outside. Therefore, it is recommended that the material of the body  110  be a metallic material having thermal conductivity. For example, the body  110  may be made of A 1  or an alloy including A 1 . 
         [0028]    It is desirable for the body  110  to have a cylindrical shape. However, the body can have various shapes without being limited to this. For example, the body  110  may have a polygonal box shape. 
         [0029]    The body  110  may have a heat radiating fin (not shown). The heat radiating fin (not shown) extends outward from the outer surface of the body  110 . The body  110  may have a plurality of the heat radiating fins. Otherwise, the heat radiating fin (not shown) may be independent of the body  110  and combined with the body  110 . The heat radiating fin (not shown) can more improve the heat radiating effect of the body  110  by increasing the surface area of the body  110 . 
         [0030]      FIG. 4  is an exploded perspective view of the light source  120  alone of the lighting apparatus shown in  FIG. 2 . 
         [0031]    Referring to  FIGS. 2 to 4 , the light source  120  is mounted on the side surface  111  of the body  110 . 
         [0032]    The light source  120  includes the substrate  121 , a light emitting diode (LED)  123 , a lens  125 , a lens holder  127  and a connector  129 . 
         [0033]    At least one LED  123 , the lens  125 , the lens holder  127  and the connector  129  are mounted on one side of the substrate  121 . The other side of the substrate  121  comes in surface contact with the side surface  111  of the body  110 . 
         [0034]    The substrate  121  may include a printed circuit pattern for electrically connecting the LED  123  with the connector  129 . Therefore, a printed circuit board (PCB) may be used as the substrate  121 . 
         [0035]    When the substrate  121  is flat and the side surface  111  of the body  110  is curved, the substrate  121  is difficult to come in surface contact with the side surface  111  of the body  110 . Therefore, though not shown in the drawings, the substrate  121  may be curved in conformity with the curved the side surface  111  of the body  110 . 
         [0036]    The LED  123  is a sort of a device emitting light. At least one LED  123  is mounted on the one side of the substrate  121 . The LED  123  may have a lateral type or a vertical type. The LED  123  may be at least one of a blue LED, red LED, yellow LED and green LED. Here, the light emitting device is not limited to the LED  123 . Any device emitting light like the LED  123  may be used as the light emitting device. 
         [0037]    When the LED  123  emits light having a specific color instead of natural light (white light), the LED  123  may further include a fluorescent layer (not shown) having at least one fluorescent material. That is, the fluorescent layer (not shown) surrounding the LED  123  may be further included. 
         [0038]    Particularly, when the LED  123  is a blue LED, the fluorescent material included in the fluorescent layer (not shown) includes at least any one selected from a group consisting of a garnet based material (YAG, TAG), a silicate based material, a nitride based material and an oxynitride based material. When the fluorescent layer (not shown) includes a yellow fluorescent material, natural light (white light) can be created. However, it is recommended that a green fluorescent material or a red fluorescent material be further included in the fluorescent layer for the purpose of improving a color rendering index and reducing a color temperature. 
         [0039]    When the fluorescent layer (not shown) is mixed with various kinds of the fluorescent materials, the addition ratio of the colors of the fluorescent materials is based on the fact that it is recommended that the green fluorescent material is more used than the red fluorescent material, and the yellow fluorescent material is more used than the green fluorescent material. 
         [0040]    The garnet based material (YAG), the silicate based material and the oxynitride based material are used as the yellow fluorescent material. The silicate based material and the oxynitride based material are used as the green fluorescent material. The nitride based material is used as the red fluorescent material. 
         [0041]    The fluorescent layer (not shown) may be mixed with various kinds of the fluorescent materials or may be configured by a layer including the red fluorescent material, a layer including the green fluorescent material and a layer including the yellow fluorescent material, which are formed separately from each other. 
         [0042]    The lens  125  is mounted on one side of the substrate  121  and covers the LED  123 . 
         [0043]    The lens  125  decreases the orientation angle of light from the LED  123 . That is, the lens  125  collimates the light emitted from the LED  123 . A general LED emits light having an orientation angle of approximately 120°. The lens  125  collimates the light emitted from the LED  123  such that the light has an orientation angle of between about 5° and 15°. 
         [0044]    The lens  125  is relevant to the reflector  130 . Specifically, this matter will be described with reference to  FIG. 5 . 
         [0045]      FIG. 5  is a perspective view for describing the relation between the reflector  130  and the lens  125  which are shown in  FIG. 2 . 
         [0046]    Referring to  FIG. 5 , when a predetermined imaginary plane  200  is provided between the reflector  130  and the lens  125  and when the lens  125  and a reflective surface  131  are projected on the imaginary plane  200 , a relation between the lens  125  and the reflector  130  can be found. 
         [0047]    Specifically, an orthogonal projection  210  of the lens  125 , which is formed on the imaginary plane  200 , is included in an orthogonal projection  230  of the reflective surface  131 , which is formed on the imaginary plane  200 . Further, with regard to a plurality of the lenses  125 , the orthogonal projections  210  of the total lenses  125  are also included in the orthogonal projection  230  of the reflective surface  131 . As such, when the orthogonal projection  210  of the lens  125  is included in the orthogonal projection  230  of the reflective surface  131 , all of the light emitted from the lens  125  can mostly reach the reflective surface  131  facing the lens  125 . Therefore, it is possible to improve the luminous efficiency of the lighting apparatus according to the embodiment of the present disclosure. 
         [0048]    Referring to  FIG. 4  again, the lens  125  includes the aforementioned fluorescent layer (not shown). Both when the LED  123  includes the fluorescent layer (not shown) and when the LED  123  does not, the lens  125  can include the fluorescent layer (not shown). The detailed description of the fluorescent layer (not shown) will be replaced with that of the aforementioned fluorescent layer (not shown). 
         [0049]    The lens holder  127  is mounted on one side of the substrate  121  and surrounds and fixes the lens  125 . The lens holder  127  securely fixes the lens  125  to the substrate  121 . 
         [0050]    It is recommended that the lens holder  127  surround at least two lenses  125 . When the lens holder  127  integrally surrounds the plurality of the lenses  125 , it is possible to reduce the amount of the light lost through the lens  125  and to decrease the intervals among the LEDs  123 , thereby reducing the total size of the lighting apparatus. 
         [0051]    The connector  129  is disposed on one lateral side of the substrate  121  and includes a projection  129 - 1  projecting outward from the substrate  121 . The projection  129 - 1  has elasticity acting in an outside direction of the substrate  121 . Therefore, when the projection  129 - 1  is given a predetermined force in an inside direction of the substrate  121 , the projection  129 - 1  is pushed into the inside of the substrate  121 . Hereafter, a relation between the connector  129  and the connection board  140  will be described with reference to  FIGS. 2, 4 and 7 . 
         [0052]    When the connection board  140  shown in  FIG. 2  is mounted on the body  110 , the projection  129 - 1  is pressed by a pad  141  of the connection board  140  shown in  FIG. 7 . That is, the connector  129  shown in  FIG. 4  is compressed to the pad  141  shown in  FIG. 7 . Thus, the connector  129  shown in  FIG. 4  can be electrically connected to the pad  141  shown in  FIG. 7  without a separate wire. A separate wire is not used, so that a manual process such as a soldering, etc., is not required. Besides, it is possible to prevent the luminous efficiency from being degraded due to the wire. Since the inside of the lighting apparatus does not include the wire, the inside can be simply configured. 
         [0053]    Referring to  FIG. 2 , the reflector  130  is mounted on the bottom surface  113  of the receiving recess  115  of the body  110 , and reflects in a predetermined direction, particularly, in the upper direction of  FIG. 2  light from the light source  120  mounted on the side surface  111  of the body  110 . 
         [0054]    The reflector  130  may have a poly-pyramid shape. Specifically, a detailed description thereof will be provided with reference to  FIG. 6 .  FIG. 6  is a perspective view showing other embodiments of the reflector  130  shown in  FIG. 2 . 
         [0055]    In this application, the poly-pyramid shape includes not only a geometrically perfect quadrangular shape or a geometrically perfect poly-pyramid shape but also a shape in which the reflective surface  131 ′ of a first reflector  130 ′ shown in the top part of  FIG. 6  is curved in the inward direction of the poly-pyramid. Further, the poly-pyramid shape includes a shape in which the reflective surface  131 ″ of a second reflector  130 ″ shown in the intermediate part of 
         [0056]      FIG. 6  is curved in the outward direction of the poly-pyramid. Further, the poly-pyramid shape includes a shape in which a predetermined upper portion of a third reflector  130 ′″ shown in the bottom part of  FIG. 6  is removed. The upper portion of the third reflector  130 ′″ shown in the bottom part of  FIG. 6  is the same as a shape formed by removing the upper portion of the reflector  130  shown in  FIG. 2 . Here, the surface of the upper portion of the reflector  130 ′″ may be, as shown, flat or curved. 
         [0057]    Referring to  FIG. 2  again, the reflector  130  has the reflective surface  131  and a non-reflective surface. The non-reflective surface comes in surface contact with the bottom surface  113  of the body  110 . The reflective surface  131  reflects the light from the light source  120  in a predetermined direction. 
         [0058]    The reflective surface  131  of the reflector  130  one-to-one corresponds to the light source  120 . In other words, the number of the reflective surfaces  131  is equal to the number of the light source  120 , and one reflective surface  131  faces one light source  120 . 
         [0059]    In  FIG. 2 , since the number of the light sources  120  is four, the reflector  130  has four reflective surfaces  131  in correspondence with the number of the light sources  120 . Therefore, the reflector  130  has a quadrangular pyramid shape. In this case, four triangular facets  131  correspond to the reflective surfaces  131 , the bottom triangular facet corresponds to the non-reflective surface. Meanwhile, although  FIG. 2  shows that the number of the light sources  120  is four and the reflector  130  has a quadrangular pyramid shape, there is no limit to this. The shape of the reflector  130  is changed according to the number of the light sources  120 . For example, if the number of the light sources  120  is three, the reflector  130  has a triangular pyramid shape. 
         [0060]    The reflective surface  131  of the reflector  130  may be a mirror surface in order to increase the reflectance thereof. 
         [0061]    The connection board  140  is connected to the body  110 . Specifically, the connection board  140  is connected to cover the receiving recess  115  of the body  110 . The detailed description thereof will be provided with reference to  FIG. 7 . 
         [0062]      FIG. 7  shows the top and bottom perspective views of the connection board  140  shown in  FIG. 2 . The bottom perspective view is obtained by turning the top perspective view upside down. 
         [0063]    Referring to  FIG. 7 , the connection board  140  includes an opening  145  through which light reflected from the reflector  130  passes. 
         [0064]    The connection board  140  includes the pad  141  electrically connected to the connector  129  of the light source  120  shown in  FIG. 4 , and includes a connector  143  receiving electric power from the outside. The pad  141  and the connector  143  are electrically connected with each other through the circuit pattern printed on the connection board  140 . That is, the connection board  140  can be a PCB like the substrate  121  of the light source  120 . Therefore, the electric power inputted through the connector  143  is transferred to the pad  141 , and then the electric power is transferred to the light source  120  because the pad  141  is electrically connected to the connector  129  of the light source  120 . 
         [0065]    Thanks to the connection board  140 , there is no requirement for a separate wire transferring the electric power to the light source  120 . Therefore, this makes it possible to simply assemble the lighting apparatus and to prevent the wire from making the internal configuration of the lighting apparatus complex. 
         [0066]    The area of the opening  145  of the connection board  140  is greater than that of the non-reflective surface of the reflector  130 . Because, if not, the light reflected from the reflector  130  is reflected by the connection board  140 , so that the luminous efficiency is degraded. 
         [0067]      FIG. 8  is an exploded perspective view for describing another embodiment of the connection board  140  of the lighting apparatus shown in  FIG. 2 . 
         [0068]    Referring to  FIG. 8 , a connection board  140 ′ electrically connects two adjacent substrates  121   a  and  121   b  with each other. Here, though  FIG. 8  shows that the connection board  140 ′ electrically connects the two adjacent substrates  121   a  and  121   b  with each other, there is no limit to this. The connection board  140 ′ can electrically connect two substrates  121   a  and  121   c  or  121   b  and  121   d  which mutually face each other. Further, the connection board  140 ′ can also electrically connect three or more substrates. 
         [0069]    When the connection board  140 ′ electrically connects the two adjacent substrates  121   a  and  121   b  with each other, both ends of the connection board  140 ′ are connected with a connector  129   a  of a first substrate  121   a  and a connector  129   b  of a second substrate  121   b  , respectively. 
         [0070]    The connection board  140 ′ is disposed to contact with the side surface  111  of the body  110 . In this case, it is recommended that the connection board  140 ′ is enclosed with an insulation material so as to insulate the connection board  140 ′ from the body  110 . This intends to prevent electrical short-cut between the body  110  and the connection board  140 ′ because the body  110  is usually made of a heat radiating material like Al that is electrically connected. Meanwhile, when the side surface  111  of the body  110  is coated with an insulation material, the connection board  140 ′ is not necessary to be enclosed with the insulation material. 
         [0071]    Here, the connection board  140 ′ can be a flexible board that is easily bent. In a case where the side surface  111  of the body  110  is predeterminedly curved or angular, the flexible connection board  140 ′ can easily come in surface contact with the side surface  111  of the body  110 . 
         [0072]    By using the connection board  140 ′, it is possible to simply assemble the lighting apparatus and to remove a soldering process which uses a separate wire. Moreover, the inside of the lighting apparatus can be simply configured for the lighting apparatus to have its smaller size. 
         [0073]      FIG. 9  is a perspective view of the cover  150  alone of the lighting apparatus shown in  FIG. 2 . 
         [0074]    Referring to  FIGS. 2, 4 and 9 , the cover  150  includes a support  153  including a coupling recess  153 - 1  for receiving the lens  125  of the light source  120 , surrounding the reflector  130  and being inserted into the receiving recess  115  of the body  110 . Here, the recess of the coupling recess  153 - 1  includes a cavity and a groove. 
         [0075]    The detailed example thereof will be described below. 
         [0076]    The cover  150  includes a cover part  151 , the support  153 , an opening  155  and a fastening hole  157 . 
         [0077]    The cover part  151  covers one side of the body  110  including the receiving recess  115 . 
         [0078]    The cover part  151  extends from one end of the support  153  in a direction perpendicular to the depth direction of the receiving recess  115  of the body  110 . Therefore, the cover part  151  and the body  110  form the appearance of the lighting apparatus according to the embodiment of the present disclosure. 
         [0079]    The support  153  is inserted into the receiving recess  115  of the body  110  and comes in contact with the bottom surface  113  of the body  110 , and thus supports the entire cover  150 . Accordingly, it is recommended that the length of the support  153  be equivalent to the depth of the receiving recess  115  of the body  110 . 
         [0080]    The support  153  surrounds the reflector  130  mounted in the body  110 . Therefore, the support  153  is used as a guide path through which the light reflected from the reflector  130  passes outward. The support  153  prevents the light reflected from the reflector  130  from being lost within the body  110 . Accordingly, the luminous efficiency of the lighting apparatus can be improved. Here, an inner surface  153 - 3  of the support  153  is coated with a reflective material for the purpose of more maximizing the luminous efficiency. 
         [0081]    The support  153  includes the coupling recess  153 - 1  for receiving the lens  125  of the light source  120  at the time of combining the support  153  with the lens  125  of the light source  120 . The inner surface  153 - 3  of the support  153  is placed on the same plane with the light emitting surface (the surface) of the lens  125 . When the lens  125  of the light source  120  is inserted into the coupling recess  153 - 1  of the support  153 , a path of the light reflected from the reflector  130  is formed by the inner surface  153 - 3  of the support  153  and the light emitting surface of the lens  125  of the light source  120 . As a result, all of the light reflected from the reflector  130  is reflected by the inner surface  153 - 3  of the support  153  without being lost within the body  110 , so that the light is emitted outward through the opening  155  of the cover  150 . 
         [0082]    The fastening hole  157  receives and fixes a fastening portion  173  of the optic plate holder  170 . The optic plate holder  170  fixes the optic plate  160  to the cover  150  by using the fastening hole  157 . 
         [0083]    Referring to  FIG. 2  again, the optic plate  160  covers the opening  155  of the cover  150  and is disposed on the cover part  151  of the cover  150 . The optic plate  160  can optically change the light emitted through the opening  155  of the cover  150 . For example, the optic plate  160  can diffuse the light emitted through the opening  155  of the cover  150 . The optic plate  160  may include a fluorescent layer (not shown). Here, a description of the fluorescent layer can be replaced with the aforementioned description of the fluorescent layer. Moreover, the optic plate  160  can have all of a diffusion function and the fluorescent layer. 
         [0084]    The optic plate holder  170  is fastened to the cover  150  and fixes the optic plate  160 . The optic plate holder  170  includes a cover part  171 , the fastening portion  173  and an opening  175 . 
         [0085]    The cover part  171  covers the optic plate  160  and includes the opening  175  through which the light that has passed through the opening  155  of the cover  150  passes. 
         [0086]    The fastening portion  173  extends outward from the cover part  171 . The fastening portion  173  is inserted and fitted to the fastening hole  157  of the cover  150 . 
         [0087]    The features, structures and effects and the like described in the embodiments are included in at least one embodiment of the present disclosure and are not necessarily limited to one embodiment. Furthermore, the features, structures and effects and the like provided in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, the contents related to the combination and modification should be construed to be included in the scope of the present disclosure. 
         [0088]    The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present disclosure. The present teaching can be readily applied to other types of apparatuses. The description of the foregoing embodiments is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.