Abstract:
A camera comprising a pair of front and rear viewfinder openings with a similar aspect ratio which defines a field of view through the front and rear viewfinder openings, and a masking device having a front masking opening with an aspect ratio that is different than the aspect ratio of the front and rear viewfinder openings and being supported to be positioned over the front viewfinder opening to change the field of view through the front and rear viewfinder openings, is characterized in that the masking device has a rear masking opening with the same aspect ratio as the front masking opening and being connected to the front masking opening to be positioned over the rear viewfinder opening when the front masking opening is positioned over the front viewfinder opening. Preferably, the masking device includes an endless masking belt having the pair of front and rear masking openings.

Description:
FIELD OF THE INVENTION 
     The invention relates generally to the field of photography, and in particular to cameras. More specifically, the invention relates to a camera with an adjustable framing or masking device for changing the format, i.e. aspect ratio (height×width), of the field of view through the viewfinder. 
     BACKGROUND OF THE INVENTION 
     Cameras in the recently introduced &#34;Advanced Photo System&#34; give you not just one print format, but a choice of three. For the classic proportions of a 35 mm print, the photographer chooses the &#34;C&#34; format. For a wider view, the full-frame &#34;H&#34; format is chosen. And for an even wider look, the &#34;P&#34; format is chosen to provide a sweeping panoramic print. The camera records the choice magnetically and/or optically on the filmstrip. The photofinisher&#39;s equipment then reads this data, and automatically prints each print in the selected format. A &#34;C&#34; format print is typically 4×6 inches. An &#34;H&#34; format print is typically 4×7 inches. And a &#34;P&#34; format print is typically 4×10 inches or 4×11.5 inches. 
     No matter which format is chosen in the camera, the exposed image areas on the filmstrip are always in the &#34;H&#34; format. This allows reprints to be made in any of the different formats. However, in order for the photographer to know how much of the subject will be included in the print, the viewfinder in the camera includes an adjustable masking device for framing the subject according to the selected format. 
     Typically, the camera comprises pair of front and rear viewfinder openings with a similar aspect ratio which defines a field of view through the front and rear viewfinder openings, and a masking device having a front masking opening with an aspect ratio that is different than the aspect ratio of the front and rear viewfinder openings. The masking device is supported to be positioned over the front viewfinder opening to change the field of view through the front and rear viewfinder openings. See prior art U.S. Pat. No. 4,973,997 issued Nov. 27, 1990 and No. 5,430,517 issued Jul. 4, 1995. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, a camera comprising a pair of front and rear viewfinder openings with a similar aspect ratio which defines a field of view through the front and rear viewfinder openings, and a masking device having a front masking opening with an aspect ratio that is different than the aspect ratio of the front and rear viewfinder openings and being supported to be positioned over the front viewfinder opening to change the field of view through the front and rear viewfinder openings, is characterized in that: 
     the masking device has a rear masking opening with the same aspect ratio as the front masking opening and being connected to the front masking opening to be positioned over the rear viewfinder opening when the front masking opening is positioned over the front viewfinder opening. 
     According to another aspect of the invention, a viewfinder for a camera comprises: 
     an endless belt having a pair of spaced front and rear viewfinder openings with a similar aspect ratio and being supported for movement to align the front and rear viewfinder openings to define a field of view through the front and rear viewfinder openings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of a camera with a variable format viewfinder pursuant to a preferred embodiment of the invention; 
     FIG. 2 is an assembled perspective view of the camera; 
     FIG. 3 is a front perspective view of an endless masking belt of the variable format viewfinder; 
     FIG. 4 is a front perspective view of the variable format viewfinder and an associated format encoder, showing the viewfinder and encoder when the &#34;C&#34; format is chosen and the shutter is closed; 
     FIG. 5 is a front perspective view of the variable format viewfinder and the associated format encoder, showing the viewfinder and encoder when the &#34;C&#34; format is chosen and the shutter is opened; 
     FIG. 6 is a front perspective view of the variable format viewfinder and the associated format encoder, showing the viewfinder and encoder when the &#34;H&#34; format is chosen and the shutter is closed; 
     FIG. 7 is a front perspective view of the variable format viewfinder and the associated format encoder, showing the viewfinder and encoder when the &#34;P&#34; format is chosen and the shutter is closed; 
     FIG. 8 is a front perspective view of the format encoder, showing the encoder when the &#34;P&#34; format is chosen and the shutter is open; 
     FIG. 9 is a front perspective view of the format encoder, showing the encoder when the &#34;C&#34; format is chosen and the shutter is open; 
     FIG. 10 is a front perspective view of the format encoder, showing the encoder when the &#34;H&#34; format is chosen and the shutter is open; 
     FIG. 11 is a plan view of a filmstrip indicating the exposed image area and a &#34;P&#34; format printed image area; 
     FIG. 12 is a plan view of the filmstrip indicating the exposed image area and a &#34;C&#34; format printed image area; and 
     FIG. 13 is a plan view of the filmstrip indicating the exposed image area and a &#34;H&#34; format printed image area. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention is disclosed as being embodied preferably in a camera with a variable format viewfinder. Because the features of a camera with a variable format viewfinder 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 camera 10 including a main body part 12. The main body part 12 has a pair of larger-front and smaller-rear aligned viewfinder openings 14 and 16 with a similar aspect ratio. A pair of front and rear viewfinder lenses 18 and 20 are positioned behind the front and rear viewfinder openings 14 and 16. An endless masking belt 22 extends between the front viewfinder opening 14 and the front viewfinder lens 18 and between the rear viewfinder opening 16 and the rear viewfinder lens 20. The endless masking belt 22 has a pair of parallel longitudinal edges 24 and 26 and respective series of perforations 28 inwardly adjacent the longitudinal edges. A top retaining plate 30 covers the endless masking belt 22. A pair of coaxial sprocket wheels 32 and 34 have respective teeth 36 for engaging the endless masking belt 22 at its perforations 28 and are rotatable to effect movement of the endless masking belt. 
     As shown in FIG. 3, the endless masking belt 22 has three pairs of front and rear masking openings 38 and 40, 42 and 44, and 46 and 48. One pair of front and rear masking openings 38 and 40 have a known standard &#34;C&#34; format, i.e. classic, aspect ratio. Another pair of front and rear masking openings 42 and 44 have a known standard &#34;P&#34; format, i.e. panoramic, aspect ratio. And a third pair of front and rear masking openings 46 and 48 have a known standard &#34;H&#34; format, i.e. almost full-frame, aspect ratio. The &#34;C&#34; format, &#34;P&#34; format and &#34;H&#34; format pairs of the front and rear masking openings 38 and 40, 42 and 44, and 46 and 48 are interspersed on the endless masking belt to locate the respective front masking openings 38, 42 and 46 in immediate succession followed by the respective rear masking openings 40, 44 and 48 in immediate succession. 
     A manual selector knob 50 is coaxially connected to the sprocket wheel 32 to be rotated to rotate that sprocket wheel to move the endless masking belt 22 and in turn rotate the sprocket wheel 34. Known stop means, not shown, limits rotation of the selector knob 187 degrees in opposite directions. The selector knob 50 is rotated to position anyone of the &#34;C&#34; format, &#34;P&#34; format and &#34;H&#34; format pairs of front and rear masking openings 38 and 40, 42 and 44 and 46 and 48 between the front viewfinder opening 14 and the front viewfinder lens 18 and between the rear viewfinder opening 16 and the rear viewfinder lens 20 to change the field of view through the front and rear viewfinder lenses 18 and 20 and the front and rear viewfinder openings 14 and 16. FIGS. 1, 2, 4 and 5 show the selector knob 50 rotated to position the &#34;C&#34; format pair of front and rear masking openings 38 and 40 between the front viewfinder opening 14 and the front viewfinder lens 18 and between the rear viewfinder opening 16 and the rear viewfinder lens 20. FIG. 7 shows the selector knob 50 rotated to position the &#34;P&#34; format pair of front and rear masking openings 42 and 44 between the front viewfinder opening 14 and the front viewfinder lens 18 and between the rear viewfinder opening 16 and the rear viewfinder lens 20. And FIG. 6 shows the selector knob 50 rotated to position the &#34;HH&#34; format pair of front and rear masking openings 46 and 48 between the front viewfinder opening 14 and the front viewfinder lens 18 and between the rear viewfinder opening 16 and the rear viewfinder lens 20. 
     The sprocket wheel 34 has an eccentric pin 52 that is rotatable within a top hole 54 in a reciprocating arm 56, which is movably supported within a slot 58 in the main body part 12. See FIGS. 1 and 4-7. An encodement disk 60 has a pair of coaxial shaft ends 62 and 64 rotatably supported on bearing supports 66 and 68 and a radial arm 70 with an eccentric pin 72 rotatable within a bottom hole 74 in the reciprocating arm 56. An optical light pipe 76 has a forward end 78 fixed within an opening 80 in the main body part 12, to face an ambient light ingress opening 82 in a lens retainer 84 for a taking lens 86, and a pair of legs 88 and 90 whose respective rear ends 92 and 94 face the encodement disk 60. A shutter blade 96 is pivotally supported on a pin 98 on the main body part 12 for opening movement to uncover the taking lens 86 and the forward end 78 of the optical pipe 76 and for closing movement to re-cover the taking lens and the forward end of the optical pipe. 
     Operation 
     Beginning with FIGS. 4, 5 and 9, when the selector knob 50 is rotated to position the &#34;C&#34; format pair of front and rear masking openings 38 and 40 of the endless masking belt 22 between the front viewfinder opening 14 and the front viewfinder lens 18 and between the rear viewfinder opening 16 and the rear viewfinder lens 20, the encodement disk 60 is rotated to position respective holes 100 and 102 adjacent the rear ends 92 and 94 of the optical light pipe 76. Consequently, when the shutter blade 96 is pivoted open, the forward end 78 of the optical light pipe 76 is uncovered to allow ambient light to be conducted via the optical light pipe to an encodement area 104 on a filmstrip 106, to expose an optical binary encodement &#34;1, 1&#34; on the encodement area. The encodement area 104 is located adjacent an exposed image area 108 on the filmstrip 106, which is effected by opening the shutter blade 96. See FIGS. 5 and 9. 
     As shown in FIGS. 7 and 8, when the selector knob 50 rotated to position the &#34;P&#34; format pair of front and rear masking openings 42 and 44 of the endless masking belt 22 between the front viewfinder opening 14 and the front viewfinder lens 18 and between the rear viewfinder opening 16 and the rear viewfinder lens 20, the encodement disk 60 is rotated to position only the hole 100 adjacent the rear end 94 of the optical light pipe 76. Consequently, when the shutter blade 96 is pivoted open, the forward end 78 of the optical light pipe 76 is uncovered to allow ambient light to be conducted via the optical light pipe to the encodement area 104 on the filmstrip 106, to expose an optical binary encodement &#34;1, 0&#34; on the encodement area. 
     As shown in FIGS. 6 and 10, when the selector knob 50 rotated to position the &#34;H&#34; format pair of front and rear masking openings 46 and 48 of the endless masking belt 22 between the front viewfinder opening 14 and the front viewfinder lens 18 and between the rear viewfinder opening 16 and the rear viewfinder lens 20, the encodement disk 58 is rotated to position neither of the holes 100 and 102 adjacent the rear ends 92 and 94 of the optical light pipe 76. Consequently, when the shutter blade 96 is pivoted open, although the forward end 78 of the optical light pipe 76 is uncovered to allow ambient light to be conducted via the optical light pipe to the rear ends 92 and 94 of the optical light pipe 76, the encodement disk 60 blocks the light from reaching the encodement area 104 on the filmstrip 106. This provides an optical binary encodement &#34;0, 0&#34; on the encodement area 104. 
     No matter which one of the &#34;C&#34;, &#34;P&#34; or &#34;H&#34; formats is chosen, the exposed image area 108 on the filmstrip 106 is substantially close to the &#34;H&#34; format. This allows reprints to be made in any of the different formats. See FIG. 13, which shows the filmstrip 106 with the exposed image area 108 and with a superimposed print image area 110 in the &#34;H&#34; format. See FIG. 11, which shows the filmstrip 106 with the exposed image area 108 and with a superimposed print image area 112 in the &#34;P&#34; format. And see FIG. 12, which shows the filmstrip 106 with the exposed image area 108 and with a superimposed print image area 114 in the &#34;C&#34; format. 
     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. 
     PARTS LIST 
     10. camera 
     12. main body part 
     14. front viewfinder opening 
     16. rear viewfinder opening 
     18. front viewfinder lens 
     20. rear viewfinder lens 
     22. endless masking belt 
     24. belt longitudinal edge 
     26. belt longitudinal edge 
     28. belt perforations 
     30. top retaining plate 
     32. sprocket wheel 
     34. sprocket wheel 
     36. sprocket teeth 
     38. &#34;C&#34; front masking opening 
     40. &#34;C&#34; rear masking opening 
     42. &#34;P&#34; front masking opening 
     44. &#34;P&#34; rear masking opening P 
     46. &#34;H&#34; front masking opening 
     48. &#34;H&#34; rear masking opening 
     50. selector knob 
     52. eccentric pin 
     54. top arm hole 
     56. reciprocating arm 
     58. slot 
     60. encodement disk 
     62. shaft end 
     64. shaft end 
     66. bearing support 
     68. bearing support 
     70. radial arm 
     72. eccentric pin 
     74. bottom arm hole 
     76. optical light pipe 
     78. forward end 
     80. opening 
     82. ambient light ingress opening 
     84. lens retainer 
     86. taking lens 
     88. leg 
     90. leg 
     92. rear end 
     94. rear end 
     96. shutter blade 
     98. pin 
     100. disk hole 
     102. disk hole 
     104. encodement area 
     106. filmstrip 
     108. exposed image area 
     110. &#34;H&#34; format print image area 
     112. &#34;P&#34; format print image area 
     114. &#34;C&#34; format print image area