Patent Publication Number: US-2011074684-A1

Title: Dust-proof computer mouse

Description:
TECHNICAL FIELD 
     The present invention generally relates to computer peripheral devices and, more particularly, to a sealed computer mouse for operation in a dusty environment. 
     BACKGROUND 
     The computer mouse is one of the most frequently failing components in the typically dusty environments where many computers are. located. Dusty environments exist in many places in the world where dust storms occur frequently. Dusty environments also exist in many factories, such as factories that deal with wood, concrete manufacturing, medical pill production, paper production, or other similar operations. In a dusty environment, dust accumulates in the computer mouse, preventing button clicks. Dust may also accumulate on the outer surface of the computer mouse, clogging the space in front of the optical sensor on the mouse. 
     As shown in  FIG. 1A , a full-featured computer mouse  100  typically includes a housing  10  that is small enough to be grasped and operated in a single hand. The housing  10  has a tipper surface  12  and a lower surface  14 . The upper surface  12  is usually a curved surface with at least one, typically two, and sometimes more than two finger depressible selection buttons  20 . The two buttons  20  shown in  FIG. 1A , commonly referred to as the left button and the right button, allow a user to perform the “left click” and “right click” action, respectively, to send commands to the computer. The housing  10  may also contain a scroller  30  on the upper surface  12 . The scroller  30  can be a scrolling wheel or a trackball that allows a user to move a pointer or a cursor on the computer screen. 
     As shown in  FIG. 1B , the lower surface  14  of the housing  10  is a flat surface that allows the mouse  100  to be moved on top of a mouse pad or other flat supporting surface. A transparent sensor dimple  16  at the lower surface  14  allows an optical sensor inside the housing  10  to detect movement of the mouse  100  relative to the mouse pad or the flat supporting surface, and to convert the mouse movement to cursor movement on the computer screen. Inside the housing  10  are electronic circuits and components that process the motion and button information, and transmit the control signals to the computer. The housing  10  is typically assembled from two or more pieces of molded plastic material. 
     In a typical work environment, the depressible buttons  20  and scroller  30  on the upper surface  12  of the housing  10  are exposed to the environment. Because the buttons  20  and scroller  30  are separated from the non-movable portion of the housing  10  by spaces  11 , dust may enter the housing  10  through the spaces  11 . The dust accumulates in the mouse  100  and in the spaces between the buttons  20 , preventing the button clicks. The dust also accumulates on the outer surface of the mouse  100 , clogging the space in front of the optical sensor. The accumulated dust may also absorb moisture from the ambient air and form unwanted conductive paths that lead to short circuits and malfunction. Therefore, the computer mouse needs to be opened and cleaned periodically. The cleaning process exposes the electronic components to potential mechanical damage and/or electrostatic discharge (ESD) damage. 
     SUMMARY 
     A dust-proof computer mouse with scroll function is disclosed. The computer mouse contains a housing having an upper surface and a lower surface, at least one depressible button on the upper surface, a scrolling area on the upper surface, an optical sensor dimple on the lower surface, and a cover layer. The housing and the depressible button define spaces around the depressible button. The cover layer covers, the spaces around the depressible button, therefore prevents dust from entering the interior of the housing through the spaces. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are top and bottom views, respectively, of a prior art computer mouse. 
         FIGS. 2A-2C  are top, side and bottom views, respectively, of a dust-proof mouse. 
         FIGS. 3A and 3B  are side and bottom views, respectively, of another embodiment of a dust-proof mouse. 
         FIG. 4  is a schematic showing another embodiment of a dust-proof mouse. 
     
    
    
     DETAIL DESCRIPTION OF PREFERRED EMBODIMENT 
     This description is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. The drawing figures are not necessarily to scale and certain features of the invention may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In the description, relative terms such as “front,” “back,” “up,” “down,” “top” and “bottom,” as well as derivatives thereof, should he construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “attached,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. 
       FIGS. 2A-2C  depict a dust-proof mouse  200  that contains a housing  10  with a upper surface  12  and a lower surface  14 , a scrolling area  40 , and a cover layer  18 . The upper surface  12  is a curved surface with at least one, typically two, and sometimes more than two finger depressible selection buttons  20 . The lower surface  14  is a flat surface with a transparent sensor dimple  16 . The cover layer  18  is a thin, elastic layer that wraps around the mouse  200  to prevent dust from entering the mouse  200  from spaces around the buttons  20 . A user can click the buttons  20  through the cover layer  18 . The scrolling area  40  serves the same function as the scroller  30  in the prior art computer mouse  100 , i.e., allowing a user to move a pointer or a cursor on the computer screen. The scrolling area  40  can be, for example, a touchpad strip or an optical finger navigator. 
     Touchpads have been widely used in laptop computers and computer mice. A touchpads controls the movement of the cursor by detecting motions of a user&#39;s finger on the touchpad. Traditional touchpads operate in one of a few different ways, all of which entail sensing the capacitance of a finger, or the capacitance between sensors. A touchpad may be designed to sense the capacitance of finger even if it is covered with a thin layer of rubber or plastic (e.g., the cover layer.  18 ). The operation of such a touchpad, however, may not be ideal. New models of touchpads often have more functions because they are pressure-sensitive. Many new touchpads have the function of tapping, which imitates the left-click button on a mouse. The user can choose and change the function of certain finger movements. For example, the normal function for tapping on the touchpad is the left-click on the mouse. The user can change it in the settings section to the right-click of the mouse. 
     The optical finger navigator, on the other hand, utilizes a high quality image system to track the motion of a finger placed on a sensor pad. Motion is tracked and processed to create two dimensional direction vectors, which arc then used by the display system on the host to control the motion of an on screen cursor. The optical finger navigator will still be highly operable even if the sensor pad is covered with a thin layer of transparent material. 
     Referring now to  FIG. 2A , the cover layer  18  is attached to all sides of the scrolling area  40  to form a dust-proof seal. In one embodiment, the cover layer  18  is glued around the touchpad strip or the optical finger navigator cover. 
     Alternatively, the cover layer  18  may cover the entire surface of mouse  200  including the scrolling area  40 . If the scrolling area  40  contains a touchpad, the cover layer  18  may be a thin layer of elastic material that will not interfere with the operation of the touch pad. If the scrolling area  40  contains an optical finger navigator, the cover layer  18  may be a thin, transparent layer that allow for normal operation of the optical finger navigator. As shown in  FIG. 2C , the cover layer  18  also covers the lower surface  14  of the mouse  200  with a transparent window  15  on top of the sensor dimple  16  to prevent dust from clogging in the sensor dimple  16 . 
     In another embodiment, only the upper surface  12  of the housing  10  is covered by the cover layer  18 . As shown in  FIG. 3A , the upper surface  12  of mouse  300  is covered by the cover layer  18  that forms a dust-proof seal around the scrolling area  40 . The lower surface  14  of the housing  10  is not covered by the cover layer  18 . The sensor dimple  16 , however, is covered with a transparent window  17  that is flush with the lower surface  14  to prevent dust from clogging the sensor dimple  16  ( FIG. 3B ). 
     In yet another embodiment, only a portion of the upper surface  12  is covered by the cover layer  18 . As shown in  FIG. 4 , the upper surface  12  of mouse  400  is molded with a recessed area  13  around the buttons  20 . The cover layer  18  is attached to the recessed area  13  to form a dust-proof seal around the buttons  20 . In this embodiment, the depth of the recessed area  13  matches the thickness of the cover layer  18  so that the top side of the cover layer  18  is flush with the upper surface  12  of the housing  10 . Similar to the embodiments shown in  FIG. 2A  and  FIG. 3B , the cover layer  18  forms a dust-proof seal around the scrolling area  40  and the sensor dimple  16  on the lower surface  14  is covered with a transparent window (not shown). 
     An embodiment of the cover layer  18  is made of an elastic material with a high resistance to wear and tear. Examples of the elastic material include, but are not limited to, natural rubber, synthetic rubber, synthetic resin having rubber elasticity. Examples of synthetic rubbers include, but are not limited to, nitrile, diene, and acrylic rubbers, as well as thermoplastic ploymers such as polyolefins, polyesters and fluorine-containing polymers. Examples of synthetic resins having rubber elasticity include, but are not limited to, ethylene/vinyl acetate copolymers, polyurethanes, polybutadiene, and flexible poly(vinyl chloride). Even polymers which are intrinsically rigid, such as poly (vinyl chloride), can be made to have rubber elasticity by incorporating a plasticizer, softener, or the like. 
     In one embodiment, the cover layer  18  is made of a high-strength, stretchable plastic. Examples of high-strength, stretchable plastics include, but are not limited to, polyethylene terephthalate (PET), polyester obtained by replacing the principal acid component or principal glycol component of PET (PET copolymer), a mixture of the preceding polymers, polyamide (12-nylon, 11-nylon, and MXD 6-nylon), and polyarylenesulfide such as PPS (polyphenylenesulfide). 
     Examples of acids that can be used to replace the principal acid component of PET include, but are not limited to, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, cyclohexanedicarboxylic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedione acid, trimellitic acid, pyromellitic acid, sulfoisophthalic acid, and their salts. 
     Examples of glycols that can be used to replace the principal glycol component of PET include, but are not limited to, propylene glycol, butanediol, pentanediol, hexanediol, neopentyl glycol, diethylene glycol, trieihylene glycol, polyethylene glycol, polytetramethylene glycol, cyclohexanedimethanol, ethylene oxide-added bisphenol A, trimethylolpropane, and pentaerythritol. 
     In another embodiment, the cover layer  18  is made of a transparent material so that no window is needed for the optical sensor at the lower surface  14 . 
     In yet another embodiment, the cover layer  18  comprises multiple sublayers. A multilayered structure takes advantage of different properties exhibited by the various sublayers in the structure. Typical of multilayered structures are multilayered films in which different layers have specific characteristics. For example, a multilayered structure may contain one or more polyester or polyolefin sublayers to provide mechanical strength and a fluoropolymer sublayer to provide an excellent moisture barrier property. 
     In one embodiment, the cover layer  18  is glued to the housing  10 . In another embodiment, the cover layer  18  comprises a heat adhesive sublayer on its inner side and is attached to the housing  10  by heat press. The heat adhesive sublayer typically comprises a thermoplastic resin with a melting point at 60° C.-140° C. In one embodiment, the cover layer  18  may have a thickness ranging from 0.1-2 mm. In another embodiment, the cover layer  18  may have a thickness ranging from 0.2-1 mm. A thicker cover layer  18  provides better resistance to wear and tear. However, the cover layer  18  needs to be thin enough so that a user may depress the buttons  20  through the cover layer  18  and feel the “click” of the buttons  20 . 
     In yet another embodiment, the dust-proof layer  18  is thicker in areas that arc subject to more wear and tear, such as the griping areas on both sides of the mouse  200  or  300  (i.e., the areas where the griping fingers hold the mouse), the areas above the buttons  20  where a linger click the buttons  20  through the cover layer  18 , and the bottom surface of the mouse  200  or  300 , where the cover layer  18  is constantly rubbed against a mouse pad or a hard surface. 
     Alternatively, the cover layer  18  may be reinforced at locations that are subject to more wear and tear with an additional layer or layers of high mechanical strength material, such as carbon fiber and nylon fiber (e.g., Kevlar®). 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to accommodate various modifications and equivalent arrangements. It will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments in accordance with the present invention be limited only by the claims and the equivalents thereof.