Abstract:
When an exposure counter in a single-use camera indicates that the maximum number of exposures on a roll of film in the camera have been exposed, a function of the camera such as an electronic flash capability is disabled to prevent unauthorized recycling of the camera. A reset code must be inputted to the camera to initialize the exposure counter and to enable the electronic flash capability, to permit authorized reuse of the camera with another roll of film.

Description:
CROSS-REFERENCED TO RELATED APPLICATIONS 
     This is a continuation-in-part of application Ser. No. 08/181,333, filed Jan. 14, 1994, now abandoned. This application is a reissue application for U.S. Pat. No.  5 , 418 , 585  issued May  23 ,  1995 , based on application Ser. No.  08 / 210 , 983 , filed Mar.  21 ,  1994 , as a continuation-in-part of application Ser. No.  08 / 181 , 333 , filed Jan.  14 ,  1994 , now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to the field of photography, and in particular to single-use cameras. More specifically, the invention relates to a method and apparatus for preventing unauthorized recycling of a single-use camera after a roll of film in the camera is completely exposed and for permitting authorized reuse of the camera when the roll of film is replaced with another one. 
     BACKGROUND OF THE INVENTION 
     Single-use cameras have recently become well known, for example, the “Kodak FunSaver 35 with FLASH”. Typically, the single-use camera is a simple point-and-shoot type which comprises a plastic inner body housing a fixed-focus taking lens, a film metering mechanism, a shutter, a frame (exposure) counter, and possibly an electronic flash unit, and a cardboard outer cover containing the inner body and having respective openings for the taking lens, a shutter release button, a film advance thumbwheel, a direct see-through view-finder, the frame counter, and a flash emission window. At the manufacturer, the inner body is loaded with a conventional 12, 24, or 36 exposure 35 mm film cartridge and substantially the entire length of the unexposed filmstrip is factory prewound from the cartridge onto a spool in the inner body. After the photographer takes a picture, he or she manually rotates the thumbwheel to rewind the exposed frame into the cartridge. The rewinding movement of the filmstrip the equivalent of slightly more than one frame rotates a metering sprocket to decrement the frame counter to its next lower numbered setting. Further details of this operation are disclosed in commonly assigned U.S. Pat. No. 5,235,366, issued Aug. 10, 1993. When the maximum number of exposures available on the filmstrip are exposed and the filmstrip is completely rewound into the cartridge, the camera is given to a photofinisher who first removes the filmstrip from the inner body to develop the negatives and then forwards the camera to the manufacturer for recycling. The manufacturer, in turn, recycles the camera by loading it with another roll of film and repeating the foregoing prewinding process. 
     PROBLEM TO BE SOLVED BY THE INVENTION 
     There is a need recognized by the industry to prevent unauthorized recycling of single-use cameras. 
     SUMMARY OF THE INVENTION 
     The invention among other things relates to a method and apparatus for preventing unauthorized recycling of a single-use camera but permitting authorized reuse of the camera. The method in a general sense comprises the steps of: 
     determining that a predetermined operation in the camera has occurred; 
     disabling a function of the camera when it is determined that the predetermined operation in the camera has occurred to prevent reuse of the camera when an exposed roll of film is replaced in the camera with an unexposed one; and 
     inputting an electrical, optical, or magnetic reset code to the camera to make the function that has been disabled re-enabled to permit authorized reuse of the camera with the unexposed roll of film. 
     In a preferred embodiment, the method comprises the steps of: 
     maintaining a count, using a counter in the camera, that indicates the number of exposures made and remaining to be made on a roll of film in the camera; 
     disabling a function of the camera when the count indicates that the roll of film in the camera is completely exposed, to substantially prevent reuse of the camera 
     when the roll of film is replaced with another one; 
     inputting a reset code to the camera; and 
     initializing the counter and re enabling the function that has been disabled when the reset code is inputted to the camera, to permit authorized reuse of the camera with the other roll of film. 
     More particularly, the method further comprises the steps of: 
     reading an identifier code provided in or on the camera before the reset code is inputted to the camera; and 
     selecting the reset code to be one that corresponds only to the identifier code that has been read. 
     Also, the method may further comprises the step of: 
     selecting the reset code to be one that matches a non-readable enabling code provided in or on the camera for triggering initializing the counter and re enabling the function that has been disabled when the reset code is inputted to the camera. 
     ADVANTAGEOUS EFFECT(S) OF THE INVENTION 
     The invention provides a way to prevent unauthorized recycling of a single-use camera and to permit authorized reuse of the camera. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front perspective view of a single-use camera with a built-in electronic flash unit; 
     FIG. 2 is a front elevation view of the camera as seen from the inside to show various components that comprise a preferred embodiment of the invention; 
     FIG. 3 is a flow chart; 
     FIG. 4 is a schematic view of other components of the preferred embodiment; and 
     FIG. 5 is a flow chart. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention is disclosed as being embodied preferably in a single-use 35 mm camera having a built-in electronic flash unit. Because the features of such a camera are generally known, the description which follows is directed in particular only to those elements forming part of or cooperating directly with the disclosed embodiment. It is to be understood, however, that other elements may take various forms known to a person of ordinary skill in the art. 
     Referring now to the drawings, FIGS. 1 and 2 show a single-use camera  1  which comprises a plastic light-tight inner body  3  housing a known fixed-focus taking lens  5 , a known film metering mechanism, not shown, a known single-blade shutter  7 , a known frame counter  9  for visibly indicating the number of exposures remaining for picture-taking, and an electronic flash unit  11 , and a cardboard outer cover or casing  13  containing the inner body and having a front opening  15  for the taking lens, a top opening  17  for a manual shatter release button  19 , a rear opening for a manual film advance thumbwheel, not shown, a front opening  21  for a front viewfinder window  23  of a direct see-through viewfinder  25 , a rear opening, not shown, for a rear viewfinder window  27 , a top opening  29  for the frame counter, a front opening  31  for a flash emission window  33 , a top opening  35  for a flash-ready light emitting diode  37 , and a front opening  39  for a manual push element  41  which is pushed to the right in FIG. 1 to ready the flash unit. 
     The flash unit  11  as shown in FIG. 2 includes a flash circuit board  43  on which is mounted a known flash tube  45  located behind the flash emission window  33 , a known flash charger circuit  47  for storing a suitable voltage to ignite the flash tube to provide flash illumination, a normally open flash charger circuit switch  49  that is closed by sliding the push element  41  to the right in FIGS. 1 and 2 to activate or energize the flash charger circuit, and an integrated control circuit (IC)  51 . The IC  51  is connected to a separate normally open shutter flash synch switch  53  which is closed every time the shutter blade  7  is pivoted clockwise in FIG. 2 to momentarily uncover the taking lens  5  to take a picture. 
     At the manufacturer, the inner body  3  is loaded with a conventional 12, 24, or 36 exposure 35 mm film cartridge and substantially the entire length of the unexposed filmstrip is factory prewound from the cartridge onto a spool, not shown, in the inner body. Also, the frame counter  9  is set to the maximum number of exposures available on the unexposed filmstrip. After the photographer takes a picture, he or she manually rotates the thumbwheel to rewind the exposed frame into the cartridge. The rewinding movement of the filmstrip the equivalent of slightly more than one frame rotates a metering sprocket, not shown, to decrement the frame counter  9  to its next lower numbered setting, e.g. from “36” to “35”. Further details of this operation are disclosed in commonly assigned U.S. Pat. No. 5,235,366, issued Aug. 10, 1993. When the maximum number of exposures available on the filmstrip are exposed and the filmstrip is completely rewound into the cartridge, the camera  1  is given to a photofinisher who first removes the filmstrip from the inner body  3  to develop the negatives and then forwards the camera to the manufacturer for recycling. The manufacturer, in turn, recycles the camera  1  by loading it with another roll of film and repeating the foregoing prewinding process. 
     The IC  51  includes a known count-down counter  55  which when initialized is set to the maximum number of exposures available on a roll of film in the camera  1  (similar to the frame counter  9 ). The counter  55  is adapted to be decremented by “1” when the shutter-flash synch switch  53  is closed by the shutter blade  7  to take a picture, to provide a count of the number of exposures remaining, to be made on the roll of film. As shown in FIG. 3, each time the shutter-flash synch switch  53  is closed, the IC  51  interrogates the counter  55  to determine whether its count is at least “1”. If the count is at least “1” the counter  55  is decremented by “1”. Conversely, if the counter is “0” the flash charger circuit  47  is disabled. 
     When the flash charger circuit  47  is disabled, the camera  1  cannot be effectively recycled unless authorized. According to the invention, there is provided a method of permitting authorized recycling of the camera  1 . This method is depicted in FIG.  5  and comprises the following steps: 
     (1) The maximum number of exposures available on a fresh roll of film loaded or to be loaded in the camera  1  is selected on a reader  57  by manually sliding a pointer  59  to the selected number “12”, “24”, or “36”. The reader  57  is shown in FIG.  4 . 
     (2) A pair of read pins  61  and  63  of the reader  57  are manually connected to respective mating contacts  65  and  67  of the IC  51  to permit the reader to read an identifier code provided by the IC. Preferably, the identifier code is unique to the IC  51  to make it more difficult to decipher that code and is in electrical digital format, e.g. a binary number. Alternatively, the identifier code can be in electrical analog format instead of electrical digital format, e.g. a predetermined voltage, current, resistance or other value. Also, the identifier code can be optical in nature, such as a bar code, or it can be magnetic in nature. 
     (3) The reader  57  includes a look-up table  69  having a plurality of identifier codes (for various IC&#39;s), one of which is the identifier code that has been read in step  2 , and a plurality of reset codes that correspond 1:1 to the identifier codes, and is adapted via a central processing unit (CPU), not shown, to select the reset code that corresponds to the identifier code that has been read in step  2 . Also, the plurality of reset codes correspond 1:1 to various enablement codes (provided in respective IC&#39;s), one of which is provided in the IC  51  for instructing that IC to trigger initializing the counter  55  and re-enabling the flash charger circuit  47 . The reset codes and the enablement codes, like the identifier code, can be a number of different types, e.g. electrical, optical, or magnetic, digital or analog. 
     (4) A pair of write pins  71  and  73  of the reader  57  are manually connected to respective mating contacts  75  and  77  of the IC  51  to input the reset code that has been selected in step  3  to the IC. Presumably, the reset code of that is inputted to the IC  51  will match the enablement code of that IC. As a result, the counter  55  will be incremented from “0” to the number of exposures selected in step  1  and the flash charger circuit  49  will be re enabled. If the reset code that is inputted to the IC  51  does not match the enablement code of that IC for some reason, a visible warning indicator  79  on the reader  57  is activated. 
     The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention. For example, instead of disabling the flash charger circuit  49  to prevent the flash function of the camera  1 , anyone of several other known functions or operations of the camera  1  such as shutter operation or film advance operation can be disabled. In this sense, the terms “functions” and “operations” are intended to be equivalents. Also, instead of counting the number of closures of the shutter-flash synch switch  53  for the purpose of disabling a function of the camera  1 , various other events may be used to determine when to disable a function of the camera. For instance, a function of the camera  1  can be disabled in response to removing an exposed roll of film from the camera, in response to removing a battery from the camera, or in response to opening the inner body  3  to remove the exposed roll of film. 
     As suggested in commonly assigned U.S. Pat. No. 5,021,811, issued Jun. 4, 1991, the flash circuit board  43  can include means for visibly indicating the number of 5 times the camera  1  has been recycled. 
     PARTS LIST FOR FIGS.  1 - 5   
       1 . camera 
       3 . inner housing 
       5 . taking lens 
       7 . shutter blade 
       9 . frame counter 
       11 . flash unit 
       13 . outer cover 
       15 . front opening 
       17 . top opening 
       19 . shutter release button 
       21 . front opening 
       23 . front viewfinder window 
       25 . see through viewfinder 
       27 . rear viewfinder window 
       29 . top opening 
       31 . front opening 
       33 . flash emission window 
       35 . top opening 
       37 . flash-ready fight emitting diode 
       39 . front opening 
       41 . push element 
       43 . flash circuit board 
       45 . flash tube 
       47 . flash charger circuit 
       49 . flash charger circuit switch 
       51 . IC 
       53 . flash-shutter synch switch 
       55 . counter 
       57 . reader 
       59 . pointer 
       61  &amp;  63 . pins 
       65  &amp;  67 . contacts 
       69 . look-up table 
       71  &amp;  73 . pins 
       75  &amp;  77 . contacts 
       79 . warning indicator