Abstract:
An anti-smear cleaning swab for cleaning delicate surfaces, comprising a body defining an elongated shaft having two opposite ends. An enlarged blade is carried at one end of the handle. A number of bores are made through the blade, these bores enabling both fluid flow therethrough and also some retensive capture of fluid droplets. A fluid absorbing cloth sheet pocket generally encloses by folding same around the blade, and is sized to fit snugly therearound.

Description:
CROSS-REFERENCE DATA 
       [0001]    This application claims the conventional priority of provisional patent application No. 60/788,113 in the United States filed Apr. 3, 2006 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Digital cameras comprise a sensor chamber in which is lodged an electronic sensor, such as a charge-coupled device (CCD) sensor or Complementary Metal Oxide Semiconductor (CMOS) sensor, onto which is projected the image of what is seen through the lens of the camera. This sensor can acquire the image projected thereon and convert it into electronic data, which is thereafter forwarded to data processing means provided on the digital camera. The data processing means then converts this electronic data into an image file of known format, such as in JPEG, TIFF or RAW formats, stored thereafter on the memory card of the camera. Of course, this sensor must remain as clean as possible, since impurities deposited thereon can undesirably alter the final image acquired by the camera. 
         [0003]    It is inevitable that during normal use of a digital camera, its sensor will become exposed to the atmosphere and its airborne impurities, such as minute airborne dust particles. More particularly, on digital cameras having interchangeable lenses such as digital single-lens reflex (DSLR) cameras, the sensor inevitably becomes exposed to the atmosphere and its impurities whenever the lens is removed from the body of the camera, for example when switching lenses. 
         [0004]    To clean the sensor of their digital cameras, digital camera owners have come up with a number of cleaning methods. One cleaning method consists in swabbing the camera sensor with a lint-free cleaning swab wetted with a few drops of dedicated cleaning liquid. Certain prior art cleaning swabs for digital camera sensors comprise a paddle-shaped rigid body defining an elongated handle and a sweeping blade integrally carried at one end of handle. A piece of lint-free cloth is wrapped around and carried by sweeping blade. In one particular embodiment of these prior art cleaning swabs, lint-free cloth is bag-shaped and slipped around sweeping blade, and is tightly held thereon by an elastic band. 
         [0005]    To use the swab, the user wets the lint-free cloth with a few drops of cleaning fluid. Thereafter, the cloth-covered sweeping blade is brought into the sensor chamber of is camera, into which the sensor is located, and the user gently scrubs the surface of the sensor therewith. The cleaning liquid wetting cloth dissolves dried specks that may be present on the sensor&#39;s surface, such as dried saliva drops blown on the camera&#39;s sensor when the camera&#39;s owner was switching lenses for example. As the swab is swept across the digital camera sensor, the swab picks up and removes the dust particles and dissolved specks from the sensor surface. The cleaning swab is then withdrawn from the camera&#39;s sensor chamber and the cleaning fluid spread on the sensor&#39;s surface evaporates. 
         [0006]    These paddle-shaped swabs exhibit an annoying disadvantage. These swabs, when used, are generally held in downwardly inclined fashion with their sweeping head pointing downwardly towards the camera&#39;s sensor. Thus, when the user wets cloth with cleaning fluid and orients the cleaning swab downwardly so as to direct it towards his camera&#39;s sensor chamber, the excess cleaning liquid not absorbed by the fibres of the cloth drips under the influence of gravity against the continuous and impervious surface of the handle&#39;s sweeping blade-shaped sweeping blade towards its outer edge. The excess cleaning fluid flowing towards the sweeping blade edge soaks the contact edge of the cloth, and can sometimes seep through and start dripping off the contact edge of cloth. Therefore, excess cleaning fluid can drip onto the camera sensor, or can be pressed out the soaked contact edge when it is swept across the surface of the sensor, resulting in an excessive amount of fluid being smeared onto the surface of the sensor. Moreover, it could be difficult for this excess cleaning liquid to be resorbed into the cloth since the latter&#39;s contact edge is already saturated with liquid. The swab is then withdrawn from the sensor chamber. The cleaning fluid can then evaporate, but since an excessive amount of cleaning fluid has been discharged from the cloth and left onto the sensor surface, the evaporation thereof has the tendency to leave streak marks on the surface of the sensor, something that is highly undesirable since such marks can alter the performance of the sensor, in particular the sharpness of the images captured by the sensor. 
       SUMMARY OF THE INVENTION 
       [0007]    In accordance with the teachings of the invention, there is disclosed an anti-smear cleaning swab for cleaning delicate surfaces, comprising a body defining an elongated handle having one end and another end opposite said one end thereof, an enlarged blade edgewisely carried at said handle one end and having one face and another face opposite said one face and a peripheral edge joining said one face and said another face, channel means provided integral to said blade and enabling fluid flow about at least one of said one face and of said another face of said blade, and a fluid absorbing pocket generally enclosing said one blade and sized to fit snugly therearound. 
         [0008]    Preferably, said channel means consists of at least a few passageways extending through said one blade and opening into said one face and into said another face of said blade. Preferably, at least some of said passageways are sized and shaped to enable fluid droplet retensive capture between said one face and said another face of said blade. Said passageways could be selected from the group comprising circular holes, oblong channels, and slots; or alternately or concurrently, from the group comprising grooves made on at least one of said one face and another face of said blade, and protrusions (e.g. spikes) integrally projecting from at least one of said one face and another face of said blade. 
         [0009]    Preferably, there is provided an elongated groove, extending lengthwisely of said handle, said handle groove cooperating with said blade channel means in promoting fluid escape from said fluid absorbing pocket, preferably under capillary forces whereby said handle groove is suitably sized and shaped therefor. 
         [0010]    Said fluid absorbing pocket could be made from a piece of folded lint-free sheet fabric, positioned relative to said blade such that a fold line of said sheet fabric is positioned adjacent a substantial portion of said blade peripheral edge, said sheet fabric being secured to said blade by hot sealing of a small fraction of said blade peripheral edge. 
         [0011]    Alternately, said fluid absorbing pocket could be made from a piece of folded lint-free sheet fabric, positioned relative to said blade such that a fold line of said sheet fabric is positioned adjacent a substantial portion of said blade peripheral edge, said sheet fabric to be sewn to said blade by a thread passing through a small portion of said sheet fabric and hookingly passing through not more than a few of said blade passageways. 
         [0012]    In an alternate embodiment of the invention, there is provided an anti-smear cleaning swab for cleaning delicate surfaces, comprising a body defining an elongated cross-sectionally quadrangular rigid handle having one end and another end opposite said one end thereof, a first enlarged rigid blade carried at said handle one end and having one face and another face opposite said one face and a peripheral edge joining said one face and said another face, a second enlarged rigid blade carried at said handle another end and having one face and another face opposite said one face and a peripheral edge joining said one face and said another face; channel means provided integral to said one blade and enabling fluid flow about at least one of said one face and said another face of said blade, and a fluid absorbing pocket generally enclosing said one blade and sized to fit snugly therearound. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0013]    In the annexed drawings: 
           [0014]      FIG. 1  is an exploded perspective view of a first embodiment of cleaning swab according to the present invention; 
           [0015]      FIG. 2  is a view similar to  FIG. 1 , but with the cleaning swab in assembled condition; 
           [0016]      FIG. 3  is a view similar to  FIG. 2 , but showing a second embodiment of cleaning swab according to the present invention; and 
           [0017]      FIG. 4  is a view similar to  FIG. 1 , but with the cleaning swab rotated half a turn. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0018]    A first embodiment of cleaning swab  10  is shown in  FIGS. 1-2  of the drawings, and comprises a body  12 , for example of paddle shape, having a generally rigid elongated shaft handle  14 , at one end of which is edgewisely affixed a wider sweeping flat blade  16 . Handle  14  may be cylindrical (as shown in  FIGS. 1-2 ), cross-sectionally quadrangular (for example, cross-sectionally rectangular, in  FIG. 3 ), or other suitable shapes. Blade  16  includes one and another opposite faces  16   a ,  16   b  ( FIGS. 1 and 4 ), and a peripheral edge  16   c  ( FIG. 1 ). Blade  16  further carries fluid channel means  20 . In the embodiment of  FIGS. 1-2 , fluid channel means consists of a number of perforations or holes  20  made transversely of blade  16 . As illustrated in  FIG. 4 , channel means  20  could alternately consist of slots or “mini-channels”,  30 , or other apertures (for example, ovoidal apertures  32 ) extending through blade  16 ; or alternately and/or concurrently, channel means  20  could consist of protrusions  34  (like spikes), grooves  36 , or ridges  38  made on at least one surface of the blade  16 . Furthermore, a pair of sew holes  22  are preferably made on blade  16 , in the vicinity of its junction with handle  14 . 
         [0019]    The cleaning swab  10  can be provided with a sweeping blade  16  of various widths. Thus, a camera owner can select a cleaning swab  10  having a blade width corresponding to his sensor size. 
         [0020]    Cleaning swab  10  further comprises a pocket member  18  sized to fit snugly around blade  16 . Blade  16  should be at least semi-rigid. Pocket member  18  is preferably made from sheet fabric. The fabric used in the confection of pocket member  18  can be any suitable lint-free fabric or cloth, and can be chosen in function of its compatibility with the specific cleaning fluid it is destined to be used with. The attachment of pocket member  18  to blade  16  can be achieved in a number of different suitable manners. In the embodiment shown in  FIGS. 1-2 , pocket member  18  is a piece of fabric folded over blade  16  along a fold line which forms contact edge  19   a , with opposite lateral edges  19   b ,  19   c  of the folded piece of fabric being cut to shape and adhered together by hot-sealing. This method can be used for cloths made with fabrics permitting hot-sealing, such as polyester or nylon fabrics, or other polymer-fibre fabrics. 
         [0021]    Alternately, pocket member  18  could consist of a piece of fabric folded over blade  16  and sewn in place by a thread passing through a sheet cloth flap of pocket member  18  and through sew holes  22  made in blade  16 . This fastening method is especially advantageous when the pocket member cloth is made of a fabric that does not allow hot-sealing, such as cellulose, cotton or rayon. 
         [0022]    It is highly desirable that the blade leading edge, i.e. the contact edge  19   a  of blade  16  opposite shaft handle  14 , be formed of a fold in the fabric rather than by a hot-seal joint. Indeed, hot sealing forms relatively rough and sharp joints which are more likely to scratch delicate surfaces than a smooth and continuous fold line. Nevertheless, it is understood that the present invention is not limited to cleaning swabs having a lint-free cloth formed of a folded piece of fabric. 
         [0023]    Cleaning swab  10  is used in the same way than the prior art cleaning swab  10  described in the hereinabove “background of the invention” paragraph”. The user wets the lint-free cloth  18  with a few drops of cleaning fluid, and the swab is ready for use on the sensor. With the present invention, when cleaning fluid is dropped on one side of the cloth of pocket member  18 , it permeates across the cloth, and can pass through the holes  20  in order to reach the other side of the fabric and thus ensure homogeneous wetting of the cloth. Moreover, with the swab of the present invention, if the cloth of pocket member  18  is wetted by an excessive amount of cleaning fluid, the liquid can be retained in fluid pockets formed by holes  20  within the thickness of blade  16 , and thus prevented from running towards the blade&#39;s outer edge  17  and thus towards cloth contact edge  19   a . It therefore prevents excessive amounts of liquid to be discharged onto the sensor surface when the swab with oversaturated cloth pocket member  18  is swept thereon. 
         [0024]    Moreover, the fluid droplet retaining action of holes  20  allows the swab to remain wet for longer periods of times without having to pour additional cleaning fluid on the cloth of pocket member  18 . Indeed, holes  20  are preferably sized and shaped to enable fluid droplets retensive capture in relation to the density of the fluid absorbed by the cloth make-up of pocket member  18 . Therefore, the cleaning fluid previously dropped onto lint-free cloth of pocket member  18  and accumulated in retaining holes  20  can gradually be transferred to the lint-free cloth as soon as cloth of pocket member  18  starts to dry out, thus preventing premature dry up of the cleaning swab. 
         [0025]    An elongated groove  14   a  may be made along handle  14 . Groove  14   a  may be provided to promote fluid escape from the damp pocket member  18 . In one embodiment, groove  14   a  could be sized and shaped to enable passive fluid motion under capillary forces from oversaturated cloth pocket member  18  along handle  14  away from blade  16 . 
         [0026]    Since cleaning fluids for digital camera sensors are designed to evaporate rapidly in order to prevent lengthy wetting of the camera sensor, this accumulation and continuous distribution of cleaning fluid in the cloth is particularly advantageous. 
         [0027]    In the second embodiment of cleaning swab  10 ′ of  FIG. 3 , a second blade  16 ′ is added to handle  14 ′ at the end of handle  14 ′ opposite, and another fluid absorbing pocket member  18 ″ is snugly mounted around a second blade  16 ″. 
         [0028]    It is understood that the cleaning swab of the present invention could be used for cleaning any delicate surface, such as the external surface of the rear and front elements on a DSLR lens, the glass of a flatbed scanner, etc. 
         [0029]    It is noted that the particular shape or size of channels  20  may vary, since mitigation of fluid oversaturation at the level of the fluid absorbing pocket member  18  ( 18 ′) is sought. Channels  20  may be holes, or alternately surface grooves made on one or both main surfaces of blade  16 , or a combination of through holes and surface grooves. The elongated groove  14   a  in the handle  14  could cooperate under capillary forces with the channel means  20  in drawing fluids away from blade  16  and along handle  14 . What is sought is to thus to substantially prevent surface smear of the external sensor or lens structure to be cleaned by cleaning swab  10  from fluid dripping under gravity forces upon fluid over-saturation of the cloth material constituting the swab blade pocket  18 .