Abstract:
A collapsible-light shield for a portable computer shields direct and indirect light from the computer display and from the eyes of the user. The light shield has four flexible panels that form a tubular shape when in use. One end of the light shield has a contoured viewing port through which the user may view the screen. The other end of the light shield has a ring-like elastic fastener that detachably secures to three sides of the computer display. Each panel has two bisecting fold lines about which the tubular light shield may be collapsed into a substantially flat profile that is a small fraction of its original size.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates in general to improving the visibility of portable computer display screens, and in particular to an improved light shield for laptop computers. Still more particularly, the present invention relates to a device for enhancing the visibility of portable computer display screens by shielding direct and indirect light from the display screen and the eyes of the user. 
     2. Description of the Prior Art 
     When portable laptop or notebook computers are used in outdoor or otherwise brightly lit environments, their display screens are often difficult to view. The display screens typically utilize a relatively low-powered liquid crystal display (LCD) to reduce power consumption and prolong battery life. Although LCD screens are more efficient, they also produce lower intensity images that are less visible than those of their desktop computer counterparts. Moreover, brightly lit environments make LCD screens appear dark for a variety of reasons. As shown in FIG. 1, direct sunlight  11  creates a direct glare or reflectance  13  on the glass of the LCD panel  15  of a portable computer  17 . In addition, indirect sunlight  21  creates a diffuse glare  23  on the LCD glass  15 . Finally, bright light conditions  25  cause the pupils of the user&#39;s eyes to constrict, thus allowing less of the illumination  29  from the computer&#39;s LCD screen to enter the user&#39;s eyes. These effects combine to make portable computers very difficult to operate in brightly lit conditions. 
     In the prior art, a number of methods and devices have been proposed to enhance the viewability of computer display images in brightly lit environments. Sunshades for electronic displays are commercially available and used primarily by professional photographers using digital cameras, and officials of sporting events that must view television monitors outdoors. 
     One example is described in U.S. Pat. No. 4,121,303. In that patent, a tubular, flexible hood 16 is provided for shielding external light from the eyes of the user and the video display screen 11 of a monitor 12. One end of the hood is attached to the monitor with an elastic band 19, and the other end of the hood is secured to the head of a user with an uncomfortable elastic band and hat 21. This design is ideally suited for use by operators of monitors who must maintain visual contact with the monitor at all times and those who need access to control knobs 15 on the monitor. The operator is unable to quickly or readily view anything but the monitor since the hood is literally wrapped around his or her head via the band and cap  21 . Moreover, since the hood 16 is a flexible material, the user must use his or her neck to maintain enough tension in the hood to prevent it from sagging and blocking his or her view of the screen. Such a physical strain on the neck of the user will certainly cause muscle fatigue. In addition, some light is still permitted to enter the hood through openings 24 for the hands of the user. Although it is conceivable that this design could be adapted for use with a portable computer, it is a highly impractical solution as outdoor users of portable computers are typically not so transfixed with their display screens. 
     Other prior art solutions for enhancing the viewability of computer display screens may be generally characterized as two types of devices: those that dramatically alter the desired small, lightweight, and portable profile of laptop users, and those that are relatively consistent with such a profile. The first type of device typically employs a series of large, stiff, cumbersome panels that surround a monitor (and, often, the computer itself) to block only some of the direct and indirect sunlight when deployed. See, e.g., U.S. Pat. Nos. 5,095,385; 3,329,770; and 5,877,896. Although some of these types of devices may be folded to reduce their overall size when not in use, their folded configuration is larger than a folded laptop computer, thereby violating the small, lightweight, and portable profile laptop users seek. Furthermore, these solutions are designed to be spaced apart from the user by such a distance that a significant amount of direct and indirect sunlight is still permitted to reach the screen, and the constricting pupils of the eyes of the user. 
     The second type of device typically employs a series of small rigid panels that are attached to the monitor or cover of the laptop computer to block direct and indirect sunlight. See, e.g., U.S. Pat. Nos. 5,905,546; 5,218,474; and 5,069,529. Unfortunately, each of these devices only shield three sides of the display and are completely open on their lower ends (just above the keyboard of the laptop). This configuration permits a significant amount of direct and indirect sunlight to reach the screen and the eyes of the user, further dilating his or her eyes. Furthermore, other than U.S. Pat. No. 5,069,529 (which is designed for a desktop computer), these solutions are spaced apart from the user by such a distance that additional direct and indirect sunlight is still permitted to reach the screen and the eyes of the user. 
     Another problem with these devices is their lack of adaptability to different sized monitors. The rigid panels of these designs are pre-cut for specific laptop models and are limited to use therewith via fasteners that are also unable to compensate for variations in display dimensions. Moreover, the device of U.S. Pat. No. 5,069,529, requires is mating grooves  1   d  (FIG. 1) to be formed in the monitor itself, thereby; further restricting its use. U.S. Pat. No. 5,905,546, uses a separate rubber band  56  (FIG. 5) to attach the device to the laptop. The rubber band may. be easily broken or misplaced to render the device unusable. Although this latter device may be reconfigured for different sized displays, the multiple flaps utilized by the device must be refolded to do so. Furthermore, the fold-in flaps  71 ,  72 ,  73 ,  74  (FIG. 1) obscure the user&#39;s view of certain areas of the screen. When not in use, the devices of this second category may be folded to reduce their overall size. However, since the panels are rigid, the size of their folded configurations are limited to the size of their respective largest panels. Thus, an improved design for shielding direct and indirect light from the display of a laptop computer and the eyes of its user is needed. 
     SUMMARY OF THE INVENTION 
     A collapsible light shield for a portable computer shields direct and indirect light from the computer display and from the eyes of the user. The light shield has four flexible panels that form a generally tubular shape when in use. One end of the light shield has a contoured viewing port through which the user may view the screen. The other end of the light shield has a ring-like elastic fastener that detachably secures to three sides of the computer display. Each panel has two bisecting fold lines about which the tubular light shield may be collapsed into a substantially flat profile that is a small fraction of its original size. 
     Accordingly, it is an object of the present invention to improve the visibility of portable computer display screens. 
     It is an additional object of the present invention to provide an improved light shield for laptop computers. 
     Still another object of the present invention is to provide a device for enhancing the visibility of portable computer display screens by shielding direct and indirect light from the display screen and the eyes of the user. 
     The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the preferred embodiment of the present invention, taken in conjunction with the appended claims and the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     So that the manner in which the features, advantages and objects of the invention, as well as others which will become apparent, are attained and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the drawings illustrate only a preferred embodiment of the invention and is therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments. 
     FIG. 1 is a schematic diagram of a conventional laptop computer during use in a brightly lit environment. 
     FIG. 2 is a front isometric view of a laptop computer fitted with a light shield constructed in accordance with the invention. 
     FIG. 3 is a rear isometric view of the laptop computer and light shield of FIG.  2 . 
     FIG. 4 is a front perspective view of the laptop computer and the light shield of FIG.  2 . 
     FIG. 5 is a top view of the laptop computer and light shield FIG.  2 . 
     FIG. 6 is a schematic diagram of the laptop computer and light shield of FIG. 2 during use in a brightly lit environment. 
     FIG. 7 is an isometric view of the light shield of FIG. 2 at an initial folded stage. 
     FIG. 8 is an isometric view of the light shield of FIG. 2 at an intermediate folded stage. 
     FIG. 9 is an isometric view of the light shield of FIG. 2 completely folded. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring again to FIG. 1, the portable computer  17 , such as a laptop or notebook computer, has a base  31  with a keyboard  33 , and a cover  35  pivotally mounted to base  31  along a keyboard  33 , and a cover  35  pivotally mounted to base  31  along its bottom edge  39 . The display screen  15  is located in cover  35  which also has a top edge  37  and two side edges  41 . Computer  17  has an open position (FIG. 1) wherein cover  35  is rotated upright for viewing display  15 , and a stowable closed position (FIG. 9) wherein cover  35  is pivoted flush against base  31  when computer  17  is not in use. 
     Referring now to FIGS. 2-5, a sunshade or ambient light shield  51  is shown mounted to computer  17  for shielding direct and indirect light from display  15 , and from the eyes of the user. In these views, light shield  51  is shown expanded in its deployed configuration, which is generally tubular in shape. The body of light shield  51  is formed by four opaque, dark-colored panels  53 ,  55 ,  57 ,  59  representing the top, bottom, left, and right sides, respectively, of light shield  51 .In the embodiment shown, top and bottom panels  53 ,  55  are identical, and left and right panels  57 ,  59  are identical. Each panel  53 ,  55 ,  57 ,  59  is formed from a flexible, resilient material that is suitable for such applications. 
     Each panel  53 ,  55 ,  57 ,  59  has two longitudinal edges  61 ,  63 , a first end  65 , a second end  67 , a bisecting longitudinal fold line  71  extending between the first and second ends  65 ,  67 , and a bisecting transverse fold line  73  extending between the longitudinal edges  61 ,  63 . Each of the longitudinal edges  61 ,  63  of each of the panels  53 ,  55 ,  57 ,  59  is hingably joined to one of the longitudinal edges  61 ,  63  of an adjacent one of the panels  53 ,  55 ,  57 ,  59 . For example, edge  61  of top panel  53  is joined to edge  63  of right panel  59 , and edge  63  of top panel  53  is joined to edge  61  of left panel  57 . In the version illustrated, the panels  53 ,  55 ,  57 ,  59  are permanently joined along their longitudinal edges  61 ,  63  by reinforcement ribs such as strips of adhesive tape  75 . 
     Light shield  51  has a viewing port  81  with a rectangular viewing area defined by the first ends  65  of panels  53 ,  55 ,  57 ,  59 . When the light shield  51  is in the deployed configuration of FIGS. 2-5, the viewing-port  81  (i.e., the first ends  65 ) is contoured to conform to a face of a user to shield direct and indirect light from the eyes of the user. Light shield  51  also has an attachment end  83  with a rectangular attachment area defined by the second ends  67  of panels  53 ,  55 ,  57 ,  59 . Note that the attachment area defined by attachment end  83  is significantly larger in surface area than the viewing area defined by viewing port  81 , such that light shield  51  tapers or narrows from attachment end  83  to viewing port  81  along all four sides. 
     The final component of light shield  51  is an elastic fastener  91  that is mounted to and circumscribes the attachment end  83 . Elastic fastener  91  preferably comprises an elasticized band located with a “sock” of flexible fabric. The fabric of elastic fastener  91  is permanently bonded to attachment end  83 . As illustrated in FIGS. 2-5, elastic fastener  91  flexibly secures the light shield  51  to the top edge  37  and two side edges  41  of the cover  35  of the portable computer  17  to shield direct and indirect light from the display screen  15 . The elasticity and flexibility of fastener  91  is also capable of accommodating computers covers with 13 to 15 inch monitors without modification. 
     In operation, light shield  51  is removably mounted to computer  17  as described above. Elastic fastener  91  is secured around the top edge  37  and side edges  41  of cover  35 . Even though the lower edge portion of fastener  91  is unsecured (FIG.  4 ), the elastic band within the sock draws the lower edge portion taut as shown such that fastener  91  does not interfere with operation of keyboard  33 . During use (FIG.  6 ), both direct light  93  and indirect light  95  are prevented from reaching display  15 . In addition, the contoured viewing port  81  prevents bright ambient light  97  from dilating the eyes of the user, thereby allowing more of the light  99  from display  15  to be viewed by the user. 
     Referring now to FIGS. 7-9, light shield  51  also has a collapsed configuration when it is not in use for easy portability and compact stowage. After light shield  51  is removed from computer  17 , left and right side panels  57 ,  59  are folded along their longitudinal fold lines  71  inward (FIG. 7) into the interior of light shield  51 . With light shield  51  in this generally flat profile, top and bottom panels  53 ,  55  are folded over along their longitudinal fold lines  71  (FIG. 8) to reduce light shield  51  to half the size of the previous step. Finally, the twice-folded light shield  51  is folded a third time about the remaining transverse fold line  73  (FIG. 9) to approximately a fourth of the size of the initial fold size. 
     The invention has several advantages. The trapezoidal shape of the present design creates a tapered viewing chamber that is optimized for the individual viewer or user of the computer screen. Prior art designs for cameras and television monitors have square panels without a tapered chamber. The tapered chamber allows for more light blockage while maintaining full view of the computer screen up to about four inches away from the viewing end of the sunshade device. The ergonomically correct curvature of the viewing end fits the user&#39;s face to further reduce sunlight exposure to the screen and user&#39;s eyes. Prior art designs have viewing ends with straight edges and do not conform to the user&#39;s face. The curved viewing end is superior at blocking light to reduce glare and allowing for maximum pupil dilation of the user&#39;s eyes. 
     The flexible “sock” method of attaching the sunshade device to the laptop cover is easy to use and accommodates various sizes of covers. The prior art designs for cameras and television monitors require semi-permanent adhesive attachments or hook-and-loop fastener strips, such as VELCRO®, to be applied to the device in order to attach the sunshade. The sock makes the sunshade easier to attach and detach, and requires no modification to the device such as applying adhesive or fasteners. The method of collapsing and folding the sunshade allows it to be easily stored in the user&#39;s laptop carrying case with minimal additional storage volume required. Prior art designs are not easily dismantled or stored for transport by the user. This significant reduction in storage size and portability feature matches the user&#39;s portable transport scenario for the notebook computer. 
     While the invention has been shown or described in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.