Abstract:
A method and apparatus for an air vent assembly is provided in which individual louvers and spacers are connected together to form chevron shaped channels that allow increased air flow while blocking the escape of direct light. The louvers are formed into a chevron shape that extends lengthwise from one end of the louver to another end of the louver. The spacers are chevron shaped and interlock or are bonded together with one another to secure the louvers and to provide a support structure such that additional spacers and louvers may be stacked together as needed to form an air vent for use in a given device.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to air vents for ventilating a device having a light source. More specifically, the present invention relates to an air vent assembly that blocks direct light without substantially restricting the flow of air through the vent. 
     2. Background Information 
     Devices requiring a light source for generating light, such as a projection display apparatus, an arc lamp, a laser device and the like, need to be ventilated to dissipate heat generated by the light while minimizing or preventing the escape of direct light emitted by the device. These types of devices are therefore typically equipped with an air vent. 
     The air vent permits the exchange of warm air from the interior of the device for cooler air exterior to the device. Projection display apparatuses in particular are often further equipped with fans to increase the airflow to accelerate the exchange of air. Thus, it is important to provide air vents that do not restrict or impede the flow of air from the interior to the exterior of the device to allow for maximum ventilation. As projection display apparatuses and the like get smaller and more sophisticated, it is also important to provide highly scalable air vents that are adaptable to a wide range of devices. The air vents should be easy to manufacture and lightweight enough to complement small, lightweight devices. 
     Prior art air vents are typically molded from a single tooled part. Consequently, prior art air vents are not only expensive to manufacture, but also difficult to redesign for use in new devices that may require larger, smaller, or differently shaped air vents. Retooling machinery to manufacture a redesigned air vent can also be expensive, requiring development resources and even new machinery. 
     Moreover, the manufacture of air vents from a single tooled part imposes certain limitations on the thickness of the individual louvers of the air vent as well as the distance between adjacent louvers. The thickness of the louvers and the distance between them dictate to a great degree the amount of air that flows through a vent. Prior art louvers with a greater thickness do not minimize airflow and, generally, do not minimize weight. For example a louver with a thickness of 5 millimeters (mm) will weigh more than a louver with a thickness of 3 mm made of the same material and having the same length and width. While some prior art air vents may be constructed out of thinner material such as sheet metal, those vents are typically simple single-vaned structures that are not capable of maximizing airflow and light blockage as is needed in devices having a light source for generating light, such as a projection display apparatus, an arc lamp, or a laser device. 
     Hence, what is needed is an air vent assembly that is scalable, easily adapted to a wide assortment of devices, and that maximizes airflow and light blockage. 
     SUMMARY 
     A method and apparatus for an air vent assembly is provided in which individual louvers and spacers are connected together to form chevron shaped channels that allow increased air flow while blocking the escape of direct light. According to one aspect of the invention, the louvers are formed into a chevron shape that extends lengthwise from one end of the louver to another end of the louver. According to another aspect of the invention, the spacers are chevron shaped and interlock or are bonded with one another to secure the louvers and to provide a support structure such that additional spacers and louvers may be stacked together as needed to form an air vent for use in a given device. 
     According to one aspect of the invention, numerous variations in the length, width, and thickness of the louvers and corresponding variations in the size of the spacers may be employed to quickly assemble an optimal air vent for a number of different devices, including presentation projectors, arc lamps, laser devices and the like, thereby eliminating the need for extensive redesign of an air vent when a new device requiring ventilation is developed. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The present invention will be described by way of exemplary embodiments, but not limitations, illustrated in the accompanying drawings in which like references denote similar elements, and in which: 
     FIG. 1 illustrates a perspective view of an air vent assembly in accordance with one embodiment of the present invention; 
     FIG. 2 illustrates a single louver of the air vent assembly illustrated in FIG. 1, in accordance with one embodiment of the present invention; 
     FIG. 3A illustrates a front perspective view of a single spacer of the air vent assembly illustrated in FIG.1, in accordance with one embodiment of the present invention; 
     FIG. 3B illustrates a rear perspective view of a single spacer of the air vent assembly illustrated in FIG.1, in accordance with one embodiment of the present invention; 
     FIG. 4 illustrates a detailed rear view of two adjacent louvers of the air vent assembly illustrated in FIG. 1, separated by spacers in accordance with one embodiment of the present invention; 
     FIG. 5 illustrates an exploded view of the air vent assembly illustrated in FIG. 1, in accordance with one embodiment of the present invention; 
     FIG. 6 illustrates a perspective view of an air vent assembly in accordance with one embodiment of the present invention; 
     FIG. 7 illustrates a perspective view of an assembly mechanism in conjunction with an air vent assembly in accordance with one embodiment of the present invention; 
     FIG. 8 illustrates a perspective view of another assembly mechanism in conjunction with an air vent assembly in accordance with one embodiment of the present invention; 
     FIG. 9 illustrates a three-quarter perspective view of the air vent assembly illustrated in FIG. 1, mounted in a device housing in accordance with one embodiment of the present invention; 
     FIG. 10 illustrates a three-quarter perspective view of the air vent assembly illustrated in FIG. 1, mounted in a device housing in accordance with one embodiment of the present invention; 
     FIG. 11 illustrates a top perspective view of the air vent assembly mounted in a device housing as illustrated in FIG. 10, and in accordance with one embodiment of the present invention; 
     FIG. 12 illustrates a top perspective view of the air vent assembly illustrated in FIG. 1, with several spacers removed to reveal the flow of air through the air vent in accordance with one embodiment of the present invention; and 
     FIG. 13 illustrates a top perspective view of the air vent assembly illustrated in FIG. 1, with several spacers removed to reveal the blockage of light through the air vent in accordance with one embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following description, various aspects of the present invention, a method and apparatus for an air vent assembly, will be described. Specific details will be set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced with only some or all of the described aspects of the present invention, and with or without some or all of the specific details. In some instances, well-known features may be omitted or simplified in order not to obscure the present invention. 
     Various operations will be described as multiple discrete steps performed in turn in a manner that is most helpful in understanding the present invention. However, the order of description should not be construed as to imply that these operations are necessarily performed in the order they are presented, or even order dependent. Lastly, repeated usage of the phrase “in one embodiment” does not necessarily refer to the same embodiment, although it may. 
     The present invention provides a method and apparatus for assembling an air vent apparatus for blocking light such as the air vent described in co-pending U.S. patent application Ser. No. 09/607,572, “Air Vent Apparatus for Blocking Light,” assigned to InFocus Corporation of Wilsonville, Oreg., the assignee of the present invention. The air vent assembly is comprised of louvers having angled vanes coupled together with interlocking spacers so as to maximize air flow and light blockage through the air vent. The louver and spacer assembly provides a lightweight air vent that substantially minimizes the amount of tooling required to manufacture the air vent. Because the air vent is assembled rather than manufactured as a single tooled part, the air vent is relatively inexpensive to make and is easily scaled to size to suit the needs of the device in which it is used. Moreover the louvers and spacers may be constructed from a variety of thin, lightweight materials, again to suit the needs of the device in which it is used. 
     FIG. 1 illustrates a perspective view of an air vent assembly in accordance with one embodiment of the present invention. The air vent assembly  100  is comprised of one or more louvers  102  separated by interlocking spacers  110 . In one embodiment, the louvers  102  are flexed lengthwise at an intermediate location  104  that runs the full length of the louver  102  to deform the louver  102  into a chevron shape having two vanes  106  and  108  extending at angles  114  and  116  on either side of the intermediary location  104 . The chevron shape is repeated in the shape of the interlocking spacer  110  so that the louvers  102  and interlocking spacers  110 , when assembled together, form parallel sets of angled channels  112  through which air may flow but light is blocked. Although the intermediary location  104  and vanes  106  and  108  are illustrated as symmetrically disposed around the center of the louver  102 , other variations in the intermediary location  104  and vanes  106  and  108  may be employed such that the vanes  106  and  108  are disposed asymmetrically at an intermediary location  104  that is located to the left or right of the center of the louver  102  without departing from the scope of the invention. Moreover, the angles  114  and  116  of the vanes  106  and  108  disposed around the intermediary location  104  and the resulting chevron shape of the louver  102  and spacer  110  may be varied depending on the air flow and light blockage requirements of the device for which the air vent  100  is assembled. 
     FIG. 2 illustrates a single louver  102  of the air vent assembly  100  illustrated in FIG. 1, in accordance with one embodiment of the present invention. In one embodiment, the louver  102  is a rectangular shape having a length  122  and a width  124 , and is constructed of a strong thin material having a certain thickness  146  such as a sheet stock of a thin substrate such as Nomex or other thin thermoplastic material. Alternatively, the louver  102  may be constructed from a material such as a polycarbonate. The material from which the louver  102  is constructed is preferably non-conductive, but the louver  102  could also be constructed from a thin metal sheet if conductivity of electric current in the device is not a concern. The material from which the louver  102  is constructed may also be dark or opaque to aid in blocking the escape of light, and preferably has a relatively high flammability rating to safely withstand the heat generated by the light source of the device for which the air vent assembly  100  is intended. As noted in the description for FIG. 1, the louver  102  is flexed lengthwise at an intermediary location  104  that runs the full length  124  of the louver  102  to deform the louver  102  into a chevron shape having two vanes  106  and  108  on either side of the intermediary location  104 . In an alternate embodiment, the louver  102  may be constructed from material that is already fixed into the chevron shape having the two vanes  106  and  108  on either side of the intermediate location  104 , or possibly from material having a flexible spine at the intermediate location  104  that permits variations in the angles  114  and  116  of the two vanes  106  and  108  that extend from the spine, or even from two separate pieces of material joined together at the intermediate location  104  to create angles  114  and  116  of the two vanes  106  and  108 . The thickness  146  of the material from which the louver  102  is constructed together with the size of the angles  114  and  116  formed when flexing the louver  102  are calibrated so that there is a maximum amount of airflow through the parallel sets of angled channels  112  of the assembled air vent  100  while at the same time blocking the escape of light. Numerous other variations in the types of material used to construct the louver may be employed without departing from the scope of the invention. 
     In one embodiment, the louver  102  has one or more anchoring openings  118  through which to locate and anchor the louver  102  to one of the interlocking spacers  110  as described more fully in FIGS. 3A-3B below. At intermittent locations or at the end of the louver  102  as shown, disposed between the anchoring openings  118 , is a tooling opening  120  through which the louvers  102  and spacers  110  may be located and anchored together to an assembly mechanism to ease the alignment of the louvers  102  and spacers  110  to facilitate the assembly of the air vent  100  as described more fully in FIG. 5 below. In one embodiment, the louver may be of sufficient length that anchoring openings  118  and tooling openings  120  are provided not just at the corners and ends of the louver as shown, but also at intermediary points along the length of the louver. 
     FIGS. 3A and 3B illustrate a front and rear perspective view respectively of a single spacer  110  of the air vent assembly  100  illustrated in FIG. 1, in accordance with one embodiment of the present invention. The spacer  110  is formed from a material such as polycarbonate into a chevron shape that corresponds to the shape of a flexed louver, the spacer  110  having two vanes  142  and  144  on either side of an intermediary location  140 , each vane having a width  132  and  136  that correspond to the total width  124  of the vanes of the louver  102 , as well as a depth  130  that determines the spacing between two adjacent louvers  102  in the air vent assembly  100  to form the angled channels  112 . Numerous other variations in the types of material used to construct the spacer  110  may be employed without departing from the scope of the invention as long as the material has a relatively high flammability rating to safely withstand the heat generated by the light source of the device for which the air vent assembly  100  is intended. 
     The vanes  142  and  144  each have a corresponding fixed angle  114  and  116  measured from the intermediary location  140  that, when assembled with the louvers  102 , determines the corresponding angles  114  and  116  of the vanes  106  and  108  of the louver  102 . 
     In one embodiment, the spacer is further provided on each vane  142  and  144  with a post  126  protruding from the front of the spacer and forming a corresponding hole  138  extending into the rear of the spacer. The post  126  and hole  138  function together as an interlocking mechanism as is known in the art where the post  126  fits snugly into the receiving hole  138  of an adjacent spacer  110  and facilitates stacking multiple spacers  110  together to form the air vent  100  as described more fully in FIG.  5 . Although illustrated as a post  126  and hole  138  interlocking mechanism, other types of interlocking mechanisms that are known in the art may be employed, such as a tab and slot interlocking mechanism, without departing from the scope of the invention, as long as the interlocking mechanism permits the secure stacking of multiple spacers  110  and corresponding louvers  102 . to form the air vent assembly  100 . 
     In one embodiment, the spacer  110  is further provided with a tooling opening  128  that corresponds to the tooling opening  120  of the louver  102  to facilitate the assembly of the air vent  100  as described more fully in FIG.  5 . In one embodiment, the tooling opening  128  is located at the intermediary location  140 . Although the intermediary location  140  and vanes  142  and  144  are illustrated as symmetrically disposed around the center of the spacer  110 , other variations in the intermediary location  140  and vanes  142  and  144  may be employed that are disposed asymmetrically to the left or right of the center of the spacer  110  without departing from the scope of the invention. Moreover, the angles  114  and  116  of the vanes  142  and  144  disposed around the intermediary location  140 , and their corresponding widths  132  and  136  and depth  130  that determine the resulting chevron shape of the spacer  110  as well as the chevron shape of the assembled louvers  102  may be varied depending on the air flow and light blockage requirements of the device for which the air vent  100  is assembled. 
     FIG. 4 illustrates a detailed rearview of two adjacent louvers  102  of the air vent assembly  100  illustrated in FIG. 1, separated by spacers  110  in accordance with one embodiment of the present invention. As shown, the louvers  102  are connected to the spacers  110  such that the anchoring openings  118  of the louvers  102  are anchored over the corresponding post  126  and aligned with the corresponding hole  138  of the spacer  110  to facilitate the assembly of the air vent  100 . In one embodiment the tooling openings  120  and  128  of the louvers  102  and spacers  110 , respectively, are aligned to further facilitate the assembly of the air vent  100 . As previously indicated, in one embodiment, the louvers  102  may be of a length such that the anchoring  118  and tooling openings  120  are located intermittently along the length of the louver, thereby permitting the louvers  102  to be connected to multiple sets of spacers  110 , and not just at the ends of the louvers  102  as illustrated. 
     FIG. 5 illustrates an exploded view of the air vent assembly  100  illustrated in FIG. 1, in accordance with one embodiment of the present invention. In the illustrated embodiment the air vent assembly  100  is assembled by interleaving together a louver  102  and two spacers  110  anchored to the louver  102  using an assembly mechanism such as a tooling rod  150  to insure that the layers of stacked louvers  102  and corresponding pairs of spacers  110  are properly aligned along the respective tooling openings  120  and  128 . The resulting assemblage of louvers  102  flexed into a chevron shape that conforms to the chevron shape of the corresponding spacers  110  is further mounted in a device housing that encases the device for which the air vent  100  is assembled as described more fully with reference to FIGS. 9-11 below. 
     In one embodiment, the assembly process begins by threading a spacer  110  onto one or more tooling rods  150  through the spacer&#39;s tooling opening  128 , followed by a chevron-shaped louver  102  through the louver&#39;s tooling opening  120 . The louver  102  is anchored over the spacer  110  by placing the louver&#39;s anchoring openings  118  over the corresponding posts  128  of the spacers. The assembly of the threaded spacer  110  and louver  102  is secured by threading an adjacent spacer  110  onto the tooling rods  150  such that the holes  138  of the adjacent spacer  110  fit snugly over the corresponding posts  126  of the previously threaded spacer  110  protruding through the anchoring openings  118  of the previously threaded louver  102 . This method of assembly locks the louver  102  in place between two spacers  110 . The process is repeated until an air vent  100  is completely assembled. In one embodiment, the assembled louvers  102  and spacers  100  may be further secured using a bonding agent, such as glue, to strengthen the post  126  and hole  138  connection between adjacent spacers  110 . 
     Other aligning mechanisms other than a tooling rod  150  may be employed to assemble the air vent  100  without departing from the scope of the invention. For example, FIG. 6 illustrates an air vent assembly  100  where the louvers  102  and spacers  110  are not be provided with the tooling openings  120  and  128  illustrated in FIG.  5 . In this case, the air vent  100  may be assembled using other assembly techniques known in the art. For example, FIG. 7 illustrates a pair of spacer magazines  170  that are used to align the spacers  110  over the louvers  102 , and the louvers  102  and spacers  110  are affixed together using some type of adhesive or other fixative as is known in the art. Alternatively, the air vent assembly  100  may be assembled in a device magazine  180  as illustrated in FIG. 8, where the louvers  102  and spacers  110  are either not provided with tooling openings  120  and  128  or where the air vent  100  is assembled without taking advantage of the tooling openings  120  and  128 , and the louvers  102  and spacers  110  are affixed together using some type of bonding agent or other fixative as is known in the art. 
     FIGS. 9-11 illustrate an air vent assembly  100  that is mounted in a device housing  160  that encases the device for which the air vent  100  is assembled. In one embodiment, illustrated in FIG. 9, the air vent  100  is mounted symmetrically in one side of the device housing  160  which is cut away to show that the inside vanes  106  extend obliquely toward the interior  164  of the device housing  160  in the same way that the outside vanes  108  extend obliquely toward the exterior  166  of the device housing  160 . In an alternate embodiment, illustrated in FIG. 10, the air vent  100  is mounted asymmetrically in one side of the device housing  160  which is cut away to show that the inside vanes  106  extend perpendicularly toward the interior  164  of the device housing  160  while the outside vanes  108  extend obliquely toward the exterior  166  of the device housing  160 . FIG. 11 illustrates a top view of the asymmetric mounting of the air vent  100  that is shown in FIG. 10 to show in further detail the perpendicular orientation of the inside vanes  106  and the oblique orientation of the outside vanes  108  in relation to the device housing  160 . In the illustrated embodiment, the perpendicular orientation of the inside vanes  106  shown in FIGS. 10-11 allows the air to flow into the parallel sets of angled channels  112  formed by the louvers  102  and interlocking spacers  110  such that the direction of the air flow  162  is substantially parallel through that portion of the channel  112  facing the interior  164  of the device housing  160 . 
     FIG. 12 illustrates a top perspective view of the air vent assembly  100  illustrated in FIG. 1, with several spacers  110  removed to reveal the flow of air  162  through the parallel sets of angled channels  112  formed by the louvers  102  and spacers  110  of the air vent assembly  100  in accordance with one embodiment of the invention. As shown, the flow of air  162  through the parallel sets of angled channels  112  is relatively unobstructed to allow the maximum possible air flow while at the same time restricting the escape of light from the interior of the device. 
     FIG. 13 illustrates a top perspective view of the air vent assembly  100  illustrated in FIG. 1, with several spacers  110  removed to reveal the path of light  163  through the parallel sets of angled channels  112  formed by the louvers  102  and spacers  110  of the air vent assembly  100  in accordance with one embodiment of the invention. As shown, the path of light  163  through the parallel sets of angled channels  112  is obstructed such that the escape of light from the interior  164  of the device within which the air vent  100  is mounted is substantially restricted or blocked from exiting to the exterior  166  of the device. 
     With reference to FIGS. 1-4, depending on the specific requirements of the device for which the air vent  100  is designed, variations in the angles  114  and  116  of the louvers  102  and spacers  110 , the lengths of the vanes  106 / 142  and  108 / 144  of the louvers  102  and spacers  110 , as well as the depth  130  of the spacer  110  may be employed without departing from the principles of the invention. For example, the vanes  106 / 142  and  108 / 144  of the louvers  102  and spacers  110  may have a certain width  132  on one side of the vent, and another width  136  on another side of the vent. Although the spacing between the louvers  102  dictated by the depth  130  of the spacers  102 , also referred to as the pitch of the louvers  102 , is typically constant within a given air vent assembly  100 , gradations in the pitch may also be accommodated by changing the depth  130  of the spacers  110 , with corresponding gradations in the width  132 / 136  and angles  114 / 116  of the vanes  106 / 142  and  108 / 144  of the louvers  102  and spacers  110 , without departing from the principles of the invention. For example, although the illustrated embodiment shows the vanes  106 / 142  and  108 / 144  having a substantially equal length, vanes  106 / 142  and  108 / 144  of unequal length may be just as readily employed without departing from the principles of the invention. 
     Accordingly, a novel method and apparatus is described for assembling an air vent  100  for a device that blocks all or nearly all direct light emitted from a light source within the device while substantially minimizing the restriction of air flow through the air vent. From the foregoing description, those skilled in the art will recognize that many other variations of the present invention are possible. Thus, the present invention is not limited by the details described. Instead, the present invention can be practiced with modifications and alterations within the spirit and scope of the appended claims.