Patent Publication Number: US-6909844-B2

Title: Camera lens module having recyclable lens barrel cap

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This is a divisional of application Ser. No. 10/324,966, filed Dec. 20, 2002 now U.S. Pat. No. 6,832,043. 
   Reference is made to commonly assigned, U.S. patent application Ser. No. 10/264,757 (U.S. Pat. No. 6,741,400), entitled: MULTIPLE POSITION LENS BARREL HAVING CAM CYLINDER WITH COMMONLY BIASED FIRST AND SECOND LENS CARRIERS, filed Oct. 4, 2002, in the name of Anthony Dirisio; Ser. No. 10/324,488 (U.S. Pat. No. 6,687,457), entitled: CAMERA FRAME ASSEMBLY HAVING FOUR-BAR LINKAGE SHUTTER ACTUATOR, filed Dec. 20, 2002, in the name of Anthony Dirisio; Ser. No. 10/327,503, entitled EXTENDABLE LENS CAMERA HAVING MECHANICAL SHUTTER BLOCKING IN INTERMEDIATE LENS POSITION, filed Dec. 20, 2002, in the name of Anthony Dirisio; Ser. No. 10/325,507 (U.S. Pat. No. 6,738,568) entitled: CAMERA FRAME ASSEMBLY HAVING SHUTTER THAT SLIDES FORWARD AND BACK WITH ZOOM LENS, filed Dec. 20, 2002, in the name of Anthony Dirisio, David J. Cornell; Ser. No. 10/325,507, entitled: CAMERA FRAME ASSEMBLY HAVING SHUTTER ACTUATOR WITH TELESCOPING STRIKER AND METHOD, filed Dec. 20, 2002, in the name of David J. Cornell; Ser. No. 10/326,450, entitled: CAMERA FRAME ASSEMBLY HAVING INDEPENDENTLY BACK-PIVOTING DRIVE HUB FOR IMPACT SHUTTER, filed Dec. 20, 2002, in the name of Anthony Dirisio. 

   FIELD OF THE INVENTION 
   The invention relates to photography and photographic cameras and equipment and more particularly relates to a recyclable lens barrel cap. 
   BACKGROUND OF THE INVENTION 
   One-time-use cameras are subject to rough usage, particularly during the initial stages of recycling following removal of exposed film. In view of this, it is common practice for one-time-use camera manufacturers to replace camera covers each time a camera is recycled, while retaining all or many of the internal camera parts. The replaced covers are reused as feedstock in the manufacture of new parts. 
   U.S. Pat. No. 5,555,062 discloses a one-time use camera, in which a lens element of a two-element taking lens is held against the frame of a one-time-use camera by a front cover of the camera. The taking lens provides a fixed focus. U.S. Pat. No. 5,400,098 discloses a camera, in which a single element taking lens is held against the frame of the camera by a combined lens holder and cassette chamber cover. 
   U.S. Pat. No. 6,104,887 discloses a detachable lens hood. U.S. Pat. No. 5,974,264 discloses a cover that protects the side wall of a lens barrel. The cover attaches to the front cover of a camera. These articles do not protect the end of a lens barrel. U.S. Pat. No. 5,327,188 discloses an adapter that attaches to a lens barrel. This adapter appears to be protective, but it is a complex assembly. 
   It would thus be desirable to provide ease of outer lens element replacement and replacement of cosmetic parts, in a camera having an extendable lens barrel. 
   SUMMARY OF THE INVENTION 
   The invention is defined by the claims. The invention, in broader aspects, provides a camera frame assembly that has an extendable lens module having a lens base, a traveler, a front lens element, and a barrel cap. The lens base defines an optical axis. The traveler moves along the optical axis between first and second positions, relative to the lens base. The traveler has a front lens seat. A front lens element is disposed in the front lens seat. A barrel cap is snapped on the traveler. The barrel cap retains the front lens element in the traveler in alignment with the optical axis. The barrel cap can be snapped off for replacement by a new or renewed barrel cap. When the barrel cap is off, the front lens element is released and can be replaced or can be held in place for reuse. 
   It is an advantageous effect of the invention that an improved extendable lens module and camera are provided, which have easy outer lens element replacement and replacement of cosmetic parts. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying figures wherein: 
       FIG. 1  is an exploded, front perspective view of an embodiment of the camera. 
       FIG. 2  is a front perspective view of the camera of FIG.  1 . 
       FIG. 3  is a front perspective view of the lens module camera of FIG.  1 . 
       FIG. 4  is a front perspective view of the lens barrel and the twist ring of the camera of FIG.  1 . 
       FIG. 5  is a fully exploded, front perspective view of the lens of the camera of FIG.  1 . 
       FIG. 6  is a cross-section of the lens of  FIG. 3 , taken substantially along line  6 — 6  of FIG.  3 . The positions of optional biasing members are indicated by lines of small circles. 
       FIG. 7  is an exploded, front perspective view of the lens barrel of FIG.  3 . 
       FIG. 8  is an exploded, rear perspective view of the lens barrel of FIG.  3 . 
       FIG. 9  is a diagrammatical view of the method of the invention. 
       FIG. 10  is a diagrammatical view of another embodiment of the method of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring initially to  FIGS. 1-8 , a camera frame assembly  10  has a zoom or focusable extending lens module  12  that has extendable lens barrel  14  joined to a lens base  16 . The term “camera frame assembly” is used here to refer to a complete camera or an incomplete subunit of a camera that can be assembled with other parts to form a complete camera. The invention is particularly advantageous in relation to a camera frame assembly that is a complete or incomplete one-time use camera. 
   A taking lens optical system  20  includes a front lens element  18 , located within the lens barrel  14 , and a base lens element  21  (shown in FIGS.  5 - 6 ), located within the lens base  16 . The taking lens  20  can optionally include one or more additional lens elements (not shown). The lens module  12  includes an extension-retraction mechanism and other parts that move the lens elements  18 , 21  relative to a capture plane (indicated by dashed line  100  in  FIG. 2 ) within the frame  22 . The extension-retraction mechanism can also move the lens elements  18 , 21  relative to each other. The nature of the extension-retraction mechanism is not critical. A particular extension-retraction mechanism is described in detail below. Other suitable mechanisms will be apparent to those of skill in the art. 
   Capture media (not shown) such as photographic film or an electronic image is held at the capture plane  100  for image capture. Features of suitable film or electronic capture units are well known to those of skill in the art. 
   Referring to  FIGS. 1-8 , the lens base  16  is mounted to a frame or chassis  22  that is held between front and rear covers  13 , 15  of the camera  10 . Other camera features can be provided as is well known in the art. Referring to  FIG. 1 , the frame has a pair of opposed chambers  102 , one can hold a film cartridge (not shown) and the other a film roll. A winding mechanism  104  advances film from the film roll, across a capture plane  100 , and back into the film cartridge. A flash unit  106  can be included and synchronized with the shutter. A viewfinder-keeper plate  108  holds parts of the winding mechanism on the frame. The flash unit and other components are mounted to the frame  22  or held between the frame  22  and covers  13 , 15 . 
   The lens module  12  extends outward from the frame  22 , through an opening  11  in the front cover  13 . The lens base  16  is mounted in a fixed position on the chassis  22 . (The term “fixed” and like terms are used herein in the sense of a physical position or relationship that is in immobile and unchanging.) 
   The lens base  16  defines an optical axis  17  along which the elements of the taking lens system  20  are arranged. The lens barrel  14  is movable forward and backward (indicated by double-headed arrow  24 ) along the optical axis  17  between a fully extended position and a fully retracted position. The movement of the lens barrel  14  may or may not include rotation about the optical axis  17 . 
   The lens base  16  has a mount  27 , a holder  29 , and a carrier  31 . The mount  27  joins the lens module  12  to the frame  22  and is configured so meet the requirements of a particular frame design. The mount  27  is fixed to the frame  22 . The manner in which the mount  27  and other parts are attached to the frame  22  is not critical. For example, the mount  27  can be attached by a friction fit or by hooks or can be otherwise fastened or adhered or bonded. 
   The mount  27  has a forward-facing cup  33  (see  FIG. 5 ) that receives the holder  29 . A central opening  35  of the mount  27  can be bordered by a masking structure  37  that blocks unwanted light, so reducing flare. The holder  29  is snapped, adhered, or otherwise fastened in fixed relation to the mount  27 . The mount  27  and holder  29  are conveniently provided as two pieces, but can be provided as a single piece. 
   The lens barrel  14  is supported by holder  29  and the lens base  16 . In addition to the front lens element  18 , the lens barrel  14  includes a traveler  26  and a barrel cap  28 . In the illustrated embodiment, the traveler  26  has a cylindrical outside wall  30  and a cross wall  32  extending in a direction perpendicular to the optical axis  17 . The cross wall  32  includes an opening  34  and a lens seat  36  adjoining the opening. The front lens element  18  rests against the seat  36 . The location of the shutter  23  is not critical. In the embodiments illustrated, the shutter  23  is located between the cross wall  32  and a backer  25  that is located in the traveler  26  and is joined to the outside wall  30 . Suitable single leaf impact shutters and suitable shutters of other types are well known to those of skill in the art. 
   A twist ring  44  is mounted on the lens base  16  and is trapped in place axially by a forward rim  40  (best seen in  FIG. 6 ) of the holder  29 . The twist ring  44  extends at least part of the way around the lens base  16 . The twist ring  44  is reversibly rotatable relative to the lens base  16  from a rightward configuration through a plurality of intermediate configurations to a leftward configuration. (As with other directional terms herein, the terms “rightward” and “leftward” are used in a relative sense and are not limiting.) The twist ring  44  is mechanically coupled to the traveler  26 , such that rotation of the twist ring  44  between the rightward and leftward configurations moves the lens barrel  14  in and out between fully extended and fully retracted positions. It is preferred that the twist ring  44  does not move axially during movement between the rightward and leftward configurations. 
   The traveler  26  includes a connector  38  that along with parts of the lens base  16  and twist ring  44  provides an extension-retraction mechanism. The connector  38  has three track followers  42 . The track followers  42  can be equally spaced about the traveler  26  to help prevent the traveler  26  from canting relative to the lens base  16 . Each track follower  42  has a pair of spaced apart posts  42   a . The twist ring  44  has an engagement portion  45  that receives the connector  38  of the traveler  26  and constrains of the traveler  26  such that the traveler  26  moves forward and backward along the optical axis  17  when the twist ring  44  is rotated between the rightward and leftward configurations. The engagement portion  45  is a set of internal tracks  46  that each receive one of the track followers  42  of the traveler  26 . In the embodiments illustrated herein, the tracks  46  are spiral ribs that extend toward the optical axis from the circumferential wall  47  of the twist ring  44 . The tracks  46  are gripped between the posts  42   a  of the respective track followers  42 . Alternatively, tracks  46  can be grooves or pairs of parallel fences that receive track followers  42  configured to ride in the grooves or between the fences. 
   The track followers  42  extend to the tracks  46  through corresponding slots  43  in the holder  29  of the lens base  16 . The slots  43  each extend parallel to the optical axis  17 . In the illustrated embodiments, there are three slots  43  and three corresponding track followers  42 . 
   The track followers  42  slide along the tracks  46  when the twist ring  44  is rotated. Since the track followers  42  are held by the slots  43  of the lens base  16 , this results in the lens barrel  14  traversing linearly inward or outward along the optical axis  17 . After movement, the traveler  26  is held in a selected position by friction. The lens barrel movement is manually powered by the user rotating the twist ring. Referring to  FIGS. 1-2 , the twist ring  44  includes a knob  41  that protrudes through a slot in the cover. The knob  41  is moved by the user to rotate the twist ring  44 . The lens barrel  14  can alternatively be powered rather than being operated manually. 
   The engagement portion  45  and corresponding connector  38  can also be changed. For example, the engagement portion  45  and connector  38  can be meshed gears or the equivalent. Other mechanisms for retracting and extending a lens barrel using a twist ring are known to those of skill in the art. 
   The carrier  31  has a base lens seat  49 . The base lens element  21  is seated in the base lens seat  49  and is held in place by a retention ring  51  that if pressed over the base lens seat  49 . The base lens element  21  can, alternatively, be fastened or adhered in some other manner. The carrier  31  has pegs  53  that extend outward in the same manner as the track followers  42  of the traveler  26 . The pegs  53  are trapped within respective slots  43  of the holder  29  rearward of respective track followers  42 . Three pegs  53  are provided on the same basis as the three track followers  42  of the traveler  26 . 
   The twist ring  44  has a rear margin  55  that is shaped into three cam surfaces  57  (a cam surface is shown in  FIG. 6 ) that face respective pegs  53 . When the twist ring  44  is rotated, the pegs  53  move against respective cam surfaces  57 . The movement is constrained by the slots  43  of the holder  29 , such that the carrier  31  cannot rotate about the optical axis  17 . 
   As shown in  FIG. 6 , the lens module  12  can, optionally, bias the carrier  31  against the cam surfaces  57  or the traveler  26  against the tracks  46 , or both. Biasing of the carrier  31  can be provided, as shown, by inclusion of a compression spring or elastomer member  59  between the carrier  31  and the mount  27 . Biasing of the traveler  26  can be provided, also as shown, by inclusion of a like spring or elastomer member  63  between the traveler  26  or backer  25  and the carrier  31 . 
   The lens base can be modified (not shown) to fix the carrier  31  to the holder  29  or the mount  27 . In that case, the cam surfaces and pegs can be eliminated. This approach is simple, but is not useful with taking lenses that require movement of a rear lens element. 
   The lens barrel  14  includes the barrel cap  28  that is mounted on the front of the traveler  26 . The barrel cap  28  is cup-shaped with a circumferential side wall  48  and a front wall  50  that is continuous with the side wall  48  at one end. One or both of the barrel cap  28  and the traveler  26  have blocking features that prevent rotation of the barrel cap about the optical axis, relative to the traveler. In the illustrated embodiments, the blocking feature of the barrel cap is a roughly rectangular plate-shaped protrusion  76  (best seen in  FIG. 8 ) that fits in a notch  78  in the outer surface of the traveler  26 . In these embodiments, the carrier  31  and mount  27  also have respective cut-outs  80 , 82  that receive the protrusion  76 , when the lens barrel  14  is fully retracted. 
   The barrel cap  28  has a brim  52  that faces the lens base  16 . The brim  52  surrounds a cap rear opening  54 . In the illustrated embodiment, the brim  52  is circular. The brim  52  can be other shapes, such as oval or rectangular. Opposite the rear opening  54  is a cap front opening  56  in the front wall  50 . In the embodiment shown in the figures, the front opening  56  is rectangular in cross-section and the front wall  50  has a front facing main portion  58  and an entry portion  60  that matches the cross-section of the front opening  56  and extends inward parallel to the optical axis  17 . The entry portion  60  is continuous with the main portion  58 . The configuration of the front opening  56  and entry portion  60  can be varied. For example, the front opening  56  can be round and the entry portion  60  tapered. The front opening  56  and the entry portion  60  are, preferably, matched to the taking lens system  20  and to the shape of the image plane in the camera  10 , so as to avoid vignetting. 
   In the embodiment shown in the figures, the side wall  48  of the barrel cap  28  extends back along the entire longitudinal length of the main part of the traveler  26 . This provides protection for the traveler  26  during use when the lens barrel  14  is extended beyond the front cover  13  and when the front cover  13  of the camera  10  has been removed during recycling. 
   The rear margin  67  of the entry portion  60  of the front wall  50  of the barrel cap  28  retains the front lens element  18  in the lens seat  36  of the traveler  26 , in alignment with the other elements of the taking lens system  20 . The barrel cap  28  can be snapped off the traveler  26  to remove the front lens element  18  for cleaning or replacement. This is particularly advantageous for one-time use cameras, in which the front lens element  18  needs to be cleaned or replaced prior to reuse. The barrel cap  28  can be cleaned or replaced at the same time. This replacement, along with replacement of the covers of the body, restores the appearance of the camera  10 . 
   The snap fit of the barrel cap  28  on the traveler  26  provides for quick and easy removal and replacement of the barrel cap  28 . The barrel cap  28  can also have a simple, easy to mold shape. This reduces costs. In the embodiment shown in the figures, the barrel cap  28  has a pair of snaps  61 . Each snap  61  has a lug  62  that is molded into the barrel cap  28  itself. The other part of each snap  61  is an engagement surface  64  of the traveler  26 . The engagement surfaces  64  are shelves formed in the outside wall  30  of the traveler. The lugs  62  lodge against respective engagement surfaces  64  when the barrel cap  28  is installed. The traveler  26  has axially extending recesses  65  leading rearward to the engagement surfaces  64  and cut-outs extending rearward from the engagement surfaces  67 . The opposed snaps  61  requires only limited flexure of the barrel cap  28  for attachment and detachment and, thus, permit a relatively tight fit between the barrel cap  28  and the traveler  26 . The snap lugs  62  are spaced from the brim  52  of the barrel cap  28  and from the front opening  56 . This provides for relatively greater strength, than if the lugs  62  were provided at the brim  52  or front opening  56  of the barrel cap  28 . 
     FIG. 9  illustrates a method for restoring a used one-time-use camera frame assembly  10   a  that incorporates the extendable lens module  12 . A used camera frame assembly or carcass  10   a  is received from a photofinisher. The used camera frame assembly  10   a  does not include a film unit (not shown). A battery (not illustrated) may also have been removed. In  FIG. 9 , the camera frame assembly  10   a  is shown with a portion  66  of the back cover  15  positioned at an angle to the remainder of the back cover  15 . This condition is typical for many one-time-use cameras at this stage in recycling, since the back cover  15  is bent open to remove the film unit. 
   In  FIG. 9 , the front and rear covers  13 , 15  are initially removed ( 200 ) from the camera frame assembly  10   a . The barrel cap  28  is next snapped off ( 202 ) the traveler  26  of the lens barrel  14 . This removal is illustrated as occurring after removal of the covers  13 , 15 , but can also occur before removal ( 200 ) of the covers  13 , 15 . In the illustrated cameras, removal ( 202 ) of the barrel cap  28  is independent of the removal ( 200 ) of the front cover  13 . The camera  10  can be modified to require removal of barrel cap and cover or covers in a particular order. 
   The removal of the barrel cap  28  releases the front lens element  18  from the lens seat  36  of the traveler  26 . The front lens element  18  is then freely movable and will not stay in place unless held in position by gravity or something that blocks movement, such as a tool (not shown). The used front lens element  18  can be dropped out or lifted out for replacement. 
   At a later stage, a replacement front lens element  18  is placed in the lens seat  36  and the lens barrel  14  is recapped ( 204 ) by snapping a replacement barrel cap  28  on the traveler  26 . The front and rear covers  13 , 15  are installed ( 206 ) over the frame  22  of the camera  10  to provide the finished camera  10 . As earlier noted, removal and replacement of front and rear covers  13 , 15  is independent of the removal and replacement of the barrel cap  28 . 
   In a particular embodiment, the used front and rear covers  13 , 15  and barrel cap  28  are replaced with new front and rear covers  13 , 15  and barrel cap  28 . Instead of use of new parts, used parts can be inspected and cleaned and replaced on the camera frame assembly  10   a . Placement can occur without cleaning and inspection, however, this is undesirable as it is likely to lead to large numbers of recycled cameras having defects. 
   If new parts are used for the covers  13 , 15  and barrel cap  28 , then the used front and rear covers  13 , 15  and barrel cap  28  can be recycled as feedstock for the molding of camera parts or other items. The covers  13 , 15  and barrel cap  28  can be composed of materials that permit production of particular parts. In that case, the covers  13 , 15  and barrel cap  28  are ground or otherwise reduced ( 208 ) to a convenient size (indicated by pellets  68  in  FIG. 8 ) and then remelted. The barrel cap  28  and covers  13 , 15  can be made of polymer-polymer blend compatible thermoplastics. This permits reuse together of different materials, if required proportions in the feedstock are met. Alternatively, the barrel cap  28  and covers can be made of the same thermoplastic. This has the advantage that proportions of the different parts in a particular feedstock do not have to be analyzed and adjusted. The front lens element  18  can also be ground or otherwise reduced ( 210 ) to a convenient size (indicated by pellets  69  in  FIG. 9 ) and then remelted. The lens element  18  feedstock is typically recycled used as filler. 
     FIG. 10  illustrates a modification of the method. Steps are generally as described in relation to  FIG. 9 , but more components are reused. In one step, indicated in dashed lines, the used front lens element  18  is cleaned ( 212 ) (indicated by a spray of cleaning material emerging from a nozzle  70 ) and the front lens element  18  is then reused. The front lens element  18  can be removed from the traveler  26  for cleaning or can be retained in the traveler  26  during inspection and cleaning. During this process, the front lens element  18  can be held in place in the lens seat  36  or can be moved out and then reseated and subsequently held in place. The front lens element  18  can be held in place, with reseating as necessary, but without cleaning or inspection or both. This latter approach is not preferred, since the risk of defective cameras is increased. 
   In another step, the barrel cap  28  is cleaned as necessary (not separately illustrated) and refinished ( 214 ) and is then reused. The refinishing is illustrated in  FIG. 10 , as a grinder  74 . Grinding and polishing can be used to remove scratches, imperfections, and the like from the used barrel cap  28 . After this step, the renewed barrel cap  28  can be placed on the traveler  26 . 
   The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.