Patent Publication Number: US-8115395-B2

Title: Self-dusting lamp device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a lamp device and, more particularly, to a self-dusting lamp device for being dusted down automatically. 
     2. Description of the Related Art 
     Generally, a conventional lamp device, such as the one disclosed in Taiwan Utility Model Publication No. M334919 entitled “Improved LED lamp structure”, includes a housing, a heat-dissipating seat, a heat-dissipating fan, and a shock absorber. The housing has a plurality of air inlets and a plurality of air outlets, and a LED substrate is mounted in the housing. The heat-dissipating seat is mounted in the housing and abuts against the LED substrate. The heat-dissipating fan is mounted on a side of the heat-dissipating seat through the shock absorber. 
     In use, the conventional lamp device is coupled to a socket on a wall, a ceiling or a table (not illustrated) for being supplied with electricity and providing illumination. Moreover, the LED substrate is supplied with electricity to emit light and thus generates undesired heat; in the meanwhile, by the heat-dissipating fan, air is drawn into an interior of the housing from an exterior thereof via the air inlet and then exhausted back to the exterior via the air outlet, so as to form air currents passing through the housing. Thereby, through the heat conducting effect of the heat-dissipating seat, the undesired heat is transferred to the environment by the air currents. Consequently, the conventional lamp device provides heat-dissipating effect and, thus, the life of the conventional lamp device is longer than those of lamps without a heat-dissipating function. 
     However, when the air flows into the interior via the air inlets by the heat-dissipating fan, dust accompanying the air is liable to accumulate gradually around the air inlets. After a long time of use, the air inlets are liable to be clogged with dust, and the clogged air inlets may adversely decrease an amount of input air, and reduce the heat-dissipating effect and shorten the life of the conventional lamp device. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a self-dusting lamp device for being dusting down automatically, avoiding user&#39;s inconvenience of dusting down the conventional lamp device regularly and manually. 
     A self-dusting lamp device according to the preferred teachings of the present invention includes a housing having an electrical connection portion on an end thereof and a light penetrating portion on the other end thereof. The housing further has an air inlet portion and an air outlet portion on the outer periphery thereof. A heat-dissipating module mounted in the housing has a heat-dissipating fan. A lighting element is coupled to the heat-dissipating module and electrically connected to the electrical connection portion. A controlling unit has a driving circuit electrically connected to the heat-dissipating fan and a direction controlling circuit electrically connected to the driving circuit. The direction controlling circuit controls the heat-dissipating fan to rotate in a normal direction or in a dusting direction via the driving circuit. Accordingly, the heat-dissipating fan rotates in the normal direction for providing the heat-dissipating effect, and the heat-dissipating fan rotates in the dusting direction for providing automatically self-dusting effect, for prolonging the life of the self-dusting lamp device. 
     The present invention will become clearer in light of the following detailed description of illustrative embodiments of this invention described in connection with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The illustrative embodiments may best be described by reference to the accompanying drawings where: 
         FIG. 1  shows an exploded, perspective view of a self-dusting lamp device according to the preferred teachings of the present invention. 
         FIG. 2  shows a cross sectional view of the self-dusting lamp device of  FIG. 1 , illustrating the heat-dissipating fan rotating in a normal direction for dissipating heat. 
         FIG. 3  shows cross sectional view of self-dusting lamp device of  FIG. 1 , illustrating the heat-dissipating fan rotating in a dusting direction for dusting down the housing. 
     
    
    
     All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood. 
     Where used in the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “first”, “second”, “end”, “portion”, “axial”, “opening”, “circumferential”, and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     A self-dusting lamp device according to the preferred teachings of the present invention is shown in  FIGS. 1-3  of the drawings and generally includes a housing  10 , a heat-dissipating module  20 , a lighting element  30  and a controlling unit  40 . The housing  10  can be a single housing or have two or more housing parts assembled together for receiving the heat-dissipating module  20 , lighting element  30 , controlling unit  40  and other elements of the self-dusting lamp device. Preferably, the housing  10  includes first and second housing parts  11 ,  12  assembled together as shown in  FIGS. 1-3 . The housing  10  has an electrical connection portion  111 , that is, a base on an end and a light penetrating portion  121  on the other end. The housing  10  further includes an air inlet portion  112  and an air outlet portion  122  on the periphery thereof. Preferably, each of the air inlet portion  112  and air outlet portion  122  includes a plurality of openings or slots spaced in a circumferential direction of the first or second housing parts  11 ,  12 . 
     The heat-dissipating module  20  is mounted in the housing  10 . The heat-dissipating module  20  at least includes a heat-dissipating fan  21 . Preferably, the heat-dissipating fan  21  is an axial-flow fan and is further coupled to a sink  22  made of heat conductive material for enhancing the heat-dissipating effect of the heat-dissipating module  20 . 
     Preferably, the lighting element  30  is a light-emitting diode (LED), a bulb, or any element that can glow when being supplied with electricity. The lighting element  30  is coupled with the heat-dissipating module  20 , preferably with a side of the sink  22  (as shown in  FIG. 2 ). The lighting element  30  is electrically connected to the electrical connection portion  111 . 
     The controlling unit  40  includes a driving circuit  41  and a direction controlling circuit  42  electrically connected to the driving circuit  41 . The driving circuit  41  is electrically connected to the heat-dissipating fan  21  of the heat-dissipating module  20 . Accordingly, the direction controlling circuit  42  controls the heat-dissipating fan  21  to rotate in a normal direction, or in a dusting direction opposed to the normal direction via the driving circuit  41 . Besides, the driving circuit  41  and the direction controlling circuit  42  can be packaged into an integrated circuit (IC). 
     When the self-dusting lamp device is in use, the electrical connection portion  111  is coupled to a socket on a wall, a ceiling or a table (not illustrated) for supplying electricity to the lighting element  30  for providing illumination. Then, light emitted from the lighting element  30  passes through the light penetrating portion  121  to the environment. Moreover, the light penetrating portion  121  can be in various colors for the self-dusting lamp device to emit a colored light, e.g. green, yellow or red light. 
     Referring to  FIG. 2 , when the lighting element  30  is supplied with electricity to emit light and thus generate undesired heat, the direction controlling circuit  42  can control the heat-dissipating fan  21  to rotate in a normal direction via the driving circuit  41 . Air is drawn from the environment via the air inlet portion  112  and then exhausted back to the environment via the air outlet portion  122 , so as to form air currents passing through the housing. Therefore, the heat conducted by the sink  22  is transferred to the environment by the air currents to provide the desired heat-dissipating effect and, thus, prolong the life of the lighting element  30 . 
     Referring to  FIG. 3 , while the heat-dissipating fan  21  lastingly draws the air into the hosing  10  via the air inlet portion  112  and cause the dust accompanying the air currents to accumulate on the air inlet portion  112 , the direction controlling circuit  42  controls the heat-dissipating fan  21  to rotate in a dusting direction, which is a reverse of the normal direction. Based on the design of an impeller of the axial-flow fan, air flows through the housing  10  reversely; that is, the air is absorbed from the air outlet portion  122 , passes through the housing  10 , and is exhausted by the air inlet portion  112 . While the air currents pass through the air inlet portion  112 , the dust accumulated on the air inlet portion  112  is removed, and thus the air inlet portion  112  is prevented from being clogged to adversely decrease the amount of input air and the life of the lighting element  30  is further prolonged. 
     Specifically, the direction controlling circuit  42  regulates the timing for the heat-dissipating fan  21  to rotate in the normal or dusting direction alternatively by the driving circuit  41 . For instance, while the self-dusting lamp device is initially actuated, the heat-dissipating fan  21  can rotate in the normal direction for a period of time (such as 10-20 seconds), and then rotate in the dusting direction for another period of time (such as 10-20 seconds) for dusting the housing  10  automatically. When the dusting is finished, the heat-dissipating fan  21  is regulated to rotate in the normal direction for dissipating heat. Alternatively, in another embodiment, while the self-dusting lamp device is initially actuated, the heat-dissipating fan  21  can rotate in the dusting direction for dusting the housing  10  automatically and then rotate in the normal direction for dissipating heat. 
     In summary, under control of the self-dusting lamp device according to the preferred teachings of the present invention, the heat-dissipating fan  21  is adjusted to rotate in a normal direction via the driving circuit  41  regulated by the direction controlling circuit  42  of the control unit  40 , for conserving the heat-dissipating effect of the heat-dissipating fan  21 . Meanwhile, the heat-dissipating fan  21  is adjusted to rotation in the dusting direction for providing the automatically self-dusting effect, preventing the air inlet portion  112  from being clogged to adversely decrease of the amount of input air. On the whole, the self-dusting lamp device according to the preferred teachings of the present invention provides the automatically self-dusting effect by the direction controlling circuit, and the heat-dissipating effect by the air drawn by the heat-dissipating fan  21  via the air inlet portion  112 , for prolonging the life of the self-dusting lamp device. 
     Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.