Photographic apparatus with lens focusing scale

Photographic apparatus including an indicating device bearing indicia for relating to the operator a distance at which a variable focusing lens assembly of the apparatus is focused. The indicating device is coupled to a focusing control system of the apparatus for movement therewith as the lens assembly is moved between distant and nearmost foci to bring the camera into coincidence with a predetermined estimation of a camera-to-subject distance for a photographic scene. In a preferred embodiment, an image of the indicia is presented in or beneath a field of view of a viewfinder mounted upon the apparatus and serves as a reminder to the operator of the distance at which the lens assembly is focused whereby an error in the focused position of the lens assembly is made obvious to the operator and a proper correction can be made before the shutter of the apparatus is released.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to the field of photography and, more particularly, 
to a device which may be incorporated with a focusing control system of a 
photographic apparatus for indicating a distance at which an objective 
lens of the apparatus is focused. 
2. Description of the Prior Art 
Conventional low cost photographic cameras are designed to provide a 
reliable and consistent performance within the range of a photographic 
environment most often encountered by an amateur photographer. To derive 
an acceptable high success rate for a "snapshot photograph" for which the 
cameras are intended, the design of such cameras is tailored not only to 
meet rigid cost limitations but also to limit the number of adjustments to 
any exposure mechanism required for any one photograph. 
Generally, distance determining devices, e.g., rangefinders, are not 
provided with conventional inexpensive cameras. Fabrication costs preclude 
an incorporation of such semi-automatic ranging devices into the cameras. 
In an attempt to expand the camera's usefulness, recently developed low 
cost cameras are structured to include mounting devices and electronic 
circuits for providing flash illumination. In this mode of operation, the 
scope of range of performance of the cameras is somewhat limited in 
comparison to their use under ambient conditions. The amateur photographer 
must remain aware of camera-to-subject distance when the camera is 
operated in the flash mode. In the flash mode, a light generating capacity 
of a flashbulb being utilized in generally determined in accordance with 
the "inverse square law" which assumes that light emanating from the bulb 
dissipates in proportion to the square of a distance from the source. 
Furthermore, the amateur photographer is often not mindful of the 
difference in operational scope of the camera when using artificial 
illumination as opposed to ambient lighting. Consequently, without the 
assistance of a device which aids the operator in bringing the camera into 
coincidence with an optimum distance for photographs taken in the flash 
mode, a relatively high percentage of exposures made by the amateur 
photographer are aborted. Therefore, an inexpensive means is required 
beyond mere admonitions in film package instructions for reminding the 
photographer to determine the optimum camera-to-subject distance and make 
the exposures within that range only. 
U.S. Pat. No. 3,315,579, issued on Apr. 25, 1967 to E. H. Land for "Dual 
Mode Control Means" discloses and defines control apparatus whereby an 
exposure value setting for a shutter mechanism operating under steady 
state light conditions is established by the use of a built-in photometer. 
With this arrangement, the diaphragms of the photometer apparatus and the 
exposure aperture may be adjusted until the area of the exposure aperture 
is correct for the level of scene brightness. However, the above procedure 
is applicable only to a scene under steady state lighting conditions or at 
a level exceeding some minimum value of scene brightness at which the 
photometer is operative. When the scene brightness is less than the 
minimum value, proper exposure can be achieved by using a flash bulb. With 
flash illumination, the area of the exposure aperture is achieved by 
adjusting the relative position of a pair of movable elements to define a 
proper aperture as a function of the distance of the subject to the 
camera. A distance scale is provided therefor by imprinting a pointer and 
indicia forming a scale graduated respectively in distance units upon a 
flange of one of the pair of movable elements such that the relative 
position of the elements defines the area of the exposure aperture for 
proper exposure of the photographic subject in the flash mode of operation 
over a range of camera-to-subject distances. The pointer is aligned with 
one of the distance units at a window provided therefor in a shutter 
housing of the camera whereby the operator is apprised, when the movable 
elements have been adjusted, to provide the proper aperture setting for 
the predetermined camera-to-subject distance, of the distance for which 
the exposure aperture is set thereby substantially improving the operation 
of a fixed speed, fixed focus camera in the flash mode. 
Camera-to-subject distance determination are also critical where popular 
priced cameras are designed for use with relatively slower speed film, for 
instance, color film as compared with black and white film. For such 
applications, simple, relatively inexpensive, variable focusing lens 
arrangement which is manually adjustable at distance settings 
corresponding to the camera operator's estimation of a camera to subject 
distance and an inexpensive but accurate distance indicator may be 
combined to aid the operator in accurately focusing the camera over an 
extended range of camera-to-subject distance. 
In the past, operators of conventional low cost cameras having a 
conventional viewfinder and variable focusing lens have first estimated 
the camera-to-subject distance and then focused the lens for that distance 
by aligning a scale graduated in distance units circumferentially arranged 
about the lens housing with an index mark included upon a face of the 
camera. In order to focus the lens the operator may find it necessary to 
lower the camera from the viewing position and look away from the 
photographic scene during the focusing of the lens. While this may not be 
an inconvenience for an experienced organized operator, it may disrupt the 
concentration of the inexperienced amateur who may subsequently discover 
upon returning the camera to the viewing position that too little or too 
much information, as it relates to the photographic scene, is presented 
within the viewfinder and must compensate therefor by moving either the 
camera or the subject to a new position whereat all of the desired image 
of the photographic scene is contained within the viewfinder. Much too 
often, the amateur operator fails to refocus the lens for the new position 
before releasing the shutter whereby the resulting photographic prints are 
substantially out of focus. 
Frequently, an operator may wish to photograph different views of the same 
photographic scene. While quickly moving about to each new location, the 
operator may forget to refocus the lens for each new camera-to-subject 
distance and continue to operate the camera at a focal setting which is 
inappropriate for a substantial number of the scenes whereby the resulting 
photographic prints shall be out of focus. Each time the operator may 
remember to focus the lens for each new camera-to-subject distance, it 
shall be necessary for the operator of a camera of this type to lower the 
camera from the viewing position and turn it to a position whereat the 
operator may view the alignment of the distance scale with the index mark 
on the face of the camera and then return the camera to the viewing 
position before releasing the camera's shutter. As a result, the 
concentration of the operator may be disrupted and the operator shall be 
required to recompose the photographic scene within the viewfinder which 
may be particularly frustrating to the operator and often to the 
photographic subject. 
Therefore, in U.S. Pat. No. 3,583,300, issued on June 8, 1971, to Bruce K. 
Johnson, for "Photographic Camera with Viewfinder" a photographic camera 
is disclosed including an adjustable distance scale upon a bezel 
encompassing a lens of the camera including a viewfinder mounted upon the 
camera such that an image of the distance scale is presented in or beside 
a field of view of the viewfinder. This arrangement permits the operator 
to make a preliminary visual estimate of the camera-to-subject distance 
and then raise the camera to a viewing position whereat the operator may 
focus the lens by moving the distance scale to an appropriate index mark 
thereon while viewing an image of the photographic scene. The arrangement 
further serves to remind the operator of the distance at which the lens is 
focused and should the setting be obviously in error, it will be obvious 
to the operator and a proper correction can be made before the camera's 
shutter is released. 
The viewfinder is mounted upon an upper surface of the camera and is 
displaced a substantial distance from a variable focusing lens. The lens 
is incorporated within a lens bezel rotatably mounted to extend externally 
beyond a forward wall of the camera's housing as disclosed in U.S. Pat. 
No. 3,893,221 issued on Dec. 26, 1973 to Walter G. Lehman, for "Lens 
Assembly Mounting Method and Apparatus." The lens bezel includes, upon an 
outer peripheral surface, a distance scale for indicating to the operator 
a distance at which the lens is focused. A periscope-like system is 
mounted forward of the face of the camera and extends above the lens bezel 
within a housing provided therefor for directing an image of the distance 
scale into the viewfinder whereby the operator may observe the distance 
scale's image simultaneously with an image of the photographic scene 
during the focusing of the lens for a preselected, visually estimated 
distance. 
However, the periscope-like system includes a plurality of reflectors 
having mirror surfaces which must be precisely positioned within the 
housing in order to direct the image of the scale in the direction of a 
specially adapted refracting portion provided therefor upon a lens of the 
viewfinder which substantially adds to the manufacturing cost of the 
camera. In addition thereto, the objective lens of the camera is 
threadably secured within the lens bezel and is adapted to remain 
externally beyond the forward face of the camera for external movement 
towards and away from the forward face during the focusing of the lens 
between the distant and nearmost foci. The lens bezel is rotated for 
rectilinear movement of the lens along its optical axis during the 
focusing of the lens between the distant and nearmost foci whereby the 
distance scale moves beneath the periscope-like system and remains within 
the field of view of the operator within the viewfinder during the 
focusing of the lens. While the periscope-like system may be adapted for 
use with most conventional cameras, it is more suitably adapted for use 
with cameras of the non-folding type having an externally mounted lens 
wherein the externally mounted optical systems do not conflict with an 
design. Incorporating such an arrangement with a compact folding camera 
would substantially add to the overall length and thickness of the camera 
when the camera is collapsed, thereby defeating the purpose of the design. 
By incorporating a compound lens system having at least one movable element 
adapted to move axially and rectilinearly between a distant and nearmost 
foci, within a shutter housing of the camera, a variable focusing, 
compact, folding camera may be developed having an overall thickness no 
greater than the thickness of the shutter housing when the camera is 
collapsed into the folded position. 
The lens system developed therefor enables the movable lens to be 
rectilinearly displaced along the optical axis within the shutter housing 
whereby the hyperfocal positioning of the lens assembly is extended to 
include sharp focusing for a variety of camera-to-subject distances. U.S. 
Pat. No. 3,619,036 issued on Nov. 9, 1971, to James G. Baker, for "Compact 
Four Element Photographic Objective Lens" is typical of such systems and 
discloses a four element objective lens which employs front-element 
focusing. The front element moves rectilineraly within the shutter housing 
of the camera and even in its forwardmost position never extends beyond a 
forward wall of the shutter housing. Therefore, the periscope-like system 
in the aforementioned U.S. Pat. No. 3,583,300 and could not be adapted for 
use with such a lens assembly to provide the desired performance 
characteristics necessary for viewing the image of the scale within the 
viewfinder of such a camera. 
In recent copending application, U.S. Pat. No. 3,971,052 issued on July 20, 
1976, in the name of William T. Plummer, for "Compact Galilean 
Viewfinder," a photographic camera clearly resembling a compact, folding 
Polaroid SX-70 Land Camera, as made and sold by Polaroid Corporation, 
Cambridge, Massachusetts, was disclosed which enabled the manufacturer to 
substantially reduce the cost of the original version by simply 
substituting a viewing system for the through-the-lens viewing system of 
the original SX-70 camera and adding an external focusing scale upon a 
ring surrounding the lens. The focusing scale, however, is not visible to 
the operator within, beneath or beside the field of view of the 
viewfinder. In addition thereto, the characters comprising the scale are 
arranged about the peripheral edges of the ring which is relatively small 
for developing a distance scale and thereby severely restricts the size of 
the characters. Again, the operator is required to remove the camera from 
the viewing position to a position whereat the operator may adjust the 
scale and make the appropriate setting before the camera is raised to 
review the photographic scene. The previously cited Polaroid SX-70 Land 
camera may be modified for use with the viewing system as disclosed in the 
aforementioned U.S. Pat. No. 3,971,052. The camera includes a compound 
lens system mounted within a shutter housing having a movable element and 
manually rotatable focusing knob coupled thereto for focusing the lens 
assembly by advancing or retracting its movable element within the 
boundaries of the shutter housing. At least one element of the lens 
assembly is mounted within a lens bezel for rectilinear movement between 
distant and nearmost foci within a focusing barrel included within the 
forward wall of the shutter housing. The lens bezel includes indicia 
forming a distance scale arranged close to the peripheral edges of the 
lens assembly. The lens assembly is brought into focus for each visually 
estimated camera-to-subject distance by rotation of the focus wheel 
whereby the lens assembly is moved to align indicia representative of that 
distance with an index mark extending longitudinally upon an inner surface 
of the focus barrel. The viewing system is mounted upon the camera such 
that an uppermost surface of the shutter housing of the camera is visible 
within the field of view of the operator when the operator is viewing the 
photographic scene through the viewfinder. However, the focusing scale 
provided therewith, as with most internally housed lens assemblies, is not 
readily accessible to the operator from the rear of the camera. The 
concentration of the operator upon the scene may be disrupted when the 
operator is required to lower the camera from the viewing position and 
turn the camera to a position whereat the forward wall is facing the 
operator whereby the operator may view the movement of an appropriate 
character on the distance scale in alignment with the index mark. 
In accordance with the present invention, it will be seen that a 
substantially simplified, inexpensive version of a focusing scale is 
provided which can be adaptably coupled to a focusing mechanism of such a 
camera and is positioned upon the camera in a convenient location whereby 
the operator is visibly reminded of the distance at which the lens is 
focused. The invention may be incorporated with a camera having a lens 
adjustably mounted for movement between a distant and nearmost foci within 
a shutter housing of the camera or mounted externally, i.e. beyond a 
forward face of the housing of the camera. 
SUMMARY OF THE INVENTION 
The instant invention relates to a photographic apparatus and, more 
particularly, to a unique distance indicating device for aiding an amateur 
photographer in focusing an objective lens of the photographic apparatus 
for a visually estimated preselected camera-to-subject distance. By 
coupling a relatively simple and inexpensive device to a focusing control 
system of the apparatus, the apparatus can be brought into coincidence 
with a desired camera-to-subject distance by the operator. The device 
operates to provide a means for indicating a distance at which a lens of 
the apparatus is focused and the operator may be substantially assured of 
establishing an optimum camera-to-subject distance for flash photography. 
In addition thereto, the device aids the photographer in sharply focusing 
the lens system at the predetermined camera-to-subject distance in 
relatively slow speed film applications where accurate focusing of the 
objective lens system is required for short distances. 
The critical distance required either for deriving an optimum flash 
exposure or for the short range focusing may preferably be determined by 
the operator in a preferred embodiment while sighting through the 
viewfinder thereby allowing the operator to concentrate on the viewing of 
the photographic scene as all the information necessary for proper 
focusing of the lens assembly is presented within the field of view of the 
viewfinder. However, the ability to view the indicating means within the 
viewfinder is not a requisite for installing the device in an apparatus 
and depends solely upon the model of apparatus with which it is used. 
Because of the simplicity of the device, it is conceivable the device may 
be located upon the camera so that the operator need not have to remove 
the camera from the viewing position but merely shift his direction of 
sight from within the viewfinder to a surface having the indicating means 
displayed therein to be apprised of the distance at which the lens of the 
camera is focused. Where appropriate, the device may be incorporated with 
the apparatus of the variety having a simple focusing objective lens by 
coupling the device to a focusing control system of the apparatus during 
the production of the apparatus. For models currently in use, the device 
can be installed as an optional device with little difficulty. In either 
case, the device substantially aids the operator to overcome an absence of 
a rangefinder implement commonly employed with more expensive cameras and 
provides at least one function of a range finder at a nominal cost. 
By installing the relatively simple device in the apparatus at a suitable 
location, the amateur photographer can be consistently apprised of a 
necessity for adjusting the lens to an appropriate camera-to-subject 
distance before releasing the shutter and exposing the film contained 
within the camera. 
The device comprises an indica-bearing member, a drum or cylinder rotatably 
mounted upon a shaft for rotation, thereabout, and a means for coupling 
the device to the lens. The camera includes a focus control system for the 
lens whereby the lens is moved between a distant and nearmost focus. In a 
preferred embodiment, the device is installed within a shutter housing of 
the apparatus for direct coupling to the lens. The focusing control system 
includes a focus wheel coupled by an idler gear to the lens for 
synchronously moving the lens therewith rectilinearly along a locus of 
travel within the shutter housing in accordance with a predetermined 
camera-to-subject distance upon adjusting the radial orientation of the 
focus wheel. A representative example of such a focusing control 
arrangement may be found in U.S. Pat. No. 3,914,777, issued to Frederick 
Slavitter on Oct. 21, 1975. 
The shutter housing includes a window suitably situated thereon for viewing 
identifying characters as they are moved into alignment with the window 
during the rotation of the focus wheel. Each identifying character 
displayed in the window defines the camera-to-subject distance for which 
the lens is focused thereby immediately and consistently reminding the 
operator to bring the lens assembly into coincidence with a predetermined 
camera-to-subject distance. 
The indicia-bearing member is formed from a sheet of resilient material, 
e.g., plastic film or spring steel having the identifying characters 
included upon a side facing in the direction of the window. The 
identifying characters form a distance scale for each focused position of 
the lens assembly within the housing. The indicia-bearing member is 
treated and preformed to provide it with a form of memorization which is 
introduced into the material during the preforming process to be described 
hereinafter. The indicia-bearing member is formed having a coiled or 
rolled cylindrical configuration and is self-rewinding when in an 
unstressed condition subsequent to the processing thereof. That is to say, 
when the band is uncoiled or unrolled into a fully extended position, 
having both ends of a pair of opposing ends secured, the band will 
self-enfold by recoiling automatically into its original coiled 
configuation upon a release of one of the ends. Therefore, it can be said 
that the band is provided with a form of memorization which enables it to 
recoil upon itself without assistance from any other mechanical means such 
as a rewinding device or take-up spring. 
The shutter housing includes therein mounting means providing structure 
including a pair of laterally spaced posts or fixed members. The indicia 
bearing member is supportably mounted upon one of the posts or fixed 
members while in the coiled cylindrical configuration and the drum is 
mounted for rotation upon a second one of the posts. A leading end of the 
indicia-bearing member is passed beneath the window with the 
indicia-bearing side thereof facing in the direction of the window for 
attachment to the drum. The second one of the posts is located upon the 
mounting surface such that the coupling means is in substantial engagement 
with the lens assembly when the drum is rotatably mounted thereon whereby 
the coupling means and the drum are rotated by the rectilinear movement of 
the lens assembly between the distant and nearmost foci within the shutter 
housing. 
The indicia-bearing member is uncoiled upon the first post and wrapped 
about the peripheral surface of the drum as the focus wheel is rotated for 
moving the lens assembly from the distant to the nearmost focus. When the 
focus wheel is rotated in an opposite direction to move the lens assembly 
from the nearmost to the distant focus that portion of the indicia bearing 
member wrapped about the peripheral surface of the drum is releasably 
unwrapped and transferred to be taken up upon the first post as the band 
recoils upon itself thereon. The form of memorization included in the 
indicia bearing member further functions, through its one end attachment 
to the drum, to maintain tension in the band for substantially sustaining 
the necessary accuracy in the established relationship between the focused 
position of the lens assembly within the housing and the identifying 
character displayed at the window defining that distance at which the lens 
assembly is in focus to provide a sharp image of the photographic object 
at the focal plane of the camera. 
In an alternative embodiment of the invention the indicia-bearing member is 
stored in a tube located upon the mounting structure in a position 
substantially the same as that previously reserved for the first post. The 
leading end of the band is threaded through a slot provided therefor in 
the tube for its attachment to the drum and for its subsequent operation 
as a distance scale in defining the focused position of the lens. The 
indicia-bearing member lies within the tube unattachably stored therein 
whereby the band is free to uncoil and recoil automatically as the lens 
assembly is moved between the distant and nearmost foci. 
In still another embodiment, the device is installed within the shutter 
housing for direct coupling with the focus wheel whereby the coupling 
means of the device and the lens are synchronously driven by the manual 
rotation of the focus wheel. The direct coupling of the device to the 
focus wheel enables the focus wheel to adjust the position of the lens for 
sharp focusing of the image of the photographic subject at the focal plane 
of the camera and further enables the indicia-bearing band to align 
characters identifying the distance for which the lens assembly is sharply 
focused in the window of the shutter housing as hereinbefore described. In 
addition thereto, the direct coupling of the device to the focus wheel 
enables rolling surfaces other than gears to be employed without 
substantial loss in the transfer of motion of the focusing member to the 
device due to slippage in a camera employing means other than a focusing 
wheel for adjusting the position of the lens. 
An object of the invention is to provide a relatively simple and 
inexpensive device which can be incorporated with an inexpensive compact 
photographic apparatus currently in use or during the production thereof 
for adding an operator of the apparatus in bringing a lens assembly of the 
apparatus into coincidence with a visually estimated or predetermined 
camera-to-subject distance by indicating to the operator the distance at 
which the lens is focused without adding to the size of the apparatus. 
Another object of the invention is to provide a relatively simple and 
inexpensive device for use with a photographic apparatus having a direct 
coupling to a lens assembly and a focusing control system therefor whereby 
the device is synchronously moved therewith to present a character 
indicating the distance at which the lens assembly is focused at a viewing 
station of the apparatus. 
A final object of the invention is to provide a relatively inexpensive 
device for a photographic camera which substantially overcomes the absence 
of a range-finding implement commonly employed with more expensive cameras 
by enabling an operator to concentrate on a photographic scene during the 
focusing of the lens for a predetermined camera-to-subject distance for 
the operator has within a field of view of the viewfinder all of the 
information for proper focusing of the lens and therefor is not required 
to look away from the photographic scene before releasing the shutter. 
Other objects of the invention will in part be obvious and will in part 
appear hereinafter. 
The invention accordingly comprises the apparatus possessing the 
construction, combination of elements and arrangement of parts which are 
exemplified in the following disclosure and the scope of the application 
which will be indicated in the claims.

DETAILED DESCRIPTION OF THE INVENTION 
Referring in more detail by reference characters, FIG. 1 of the drawings 
wherein there is shown a preferred embodiment of the instant invention in 
the form of a folding camera 10 on top of which there is mounted a folding 
Galilean viewfinder 12 of the type disclosed and described in detail in 
the aforementioned U.S. Pat. No. 3,971,052. While the camera 10 may be of 
any conventional construction, as shown, it clearly resembles the compact, 
folding Polaroid SX-70 Land Camera Model 3, as made and sold by Polaroid 
Corporation of Cambridge, Massachusetts. 
Camera 10 includes a plurality of housing sections generally designated 14, 
16, 18 and 20. Extending upwardly in an erected position from housing 
section 18 is the Galilean viewfinder 12 through which a photographic 
scene to be photographed may be viewed. 
Housing section 20 comprises a shutter housing including a shutter release 
button 22, a lens 24, a focusing barrel 26, a lens bezel 28, a decorative 
ring 29 for the focusing barrel 26, a photocell window 30 and a bezel 31 
therefor through which a conventional photocell forming a part of any 
conventional exposure control system may be exposed to artificial or 
ambient illumination. A focus wheel 32 extending through a slot in the 
housing section 20 is employed to move at least one element of the lens 24 
rectilinearly along a locus within the focusing barrel 26 between a 
distant and nearmost foci for sharp focusing of the lens 24 at the focal 
plane of the camera 10. 
The shutter housing 20 includes a cover 34, an opposing pair of side walls 
42 and a frontplate 44. The cover 34 includes a viewing station or window 
36 having diametrically opposed edges 35 and 37 provided within a top 
surface thereof for viewing an identifying character 38 therein which 
defines the distance at which the lens 24 is focused within the housing 
section 20 to provide the sharply defined image of the photographic scene 
or object at the focal plane of the camera 10. 
It will be noted that the window 36 is formed within a pedestal 40 
previously reserved as a mounting pedestal including a socket for 
receiving a flash array for providing artificial illumination for flash 
exposures of photographs made with the Polaroid SX-70 Land Camera as 
disclosed in U.S. Pat. No. 3,820,128, issued on June 25, 1974 to John P. 
Burgarella et al for "Flash Photographic Control System." In a recent 
copending application, Ser. No. 569,749 filed Apr. 21, 1975 in the name of 
John A Lewis, Jr., for "Flash Mounting Means for Camera with Folding 
Viewfinder" there was disclosed a Galilean viewfinder including a flash 
socket upon a top surface of the viewfinder for receiving the flash array. 
By relocating the flash socket from the pedestal to the top of the 
viewfinder, the operator may mount the flash array out of the field of the 
viewfinder during flash exposures made with a modified version of the 
Polaroid SX-70 Camera incorporating such a viewfinder. Therefore, by 
substituting such a viewfinder for the through-the-lens viewfinder of the 
SX-70 Land Camera, essentially shown and described in U.S. Pat. No. 
3,710,697 issued on Jan. 16, 1973, a simplied version of the SX-70 Land 
Camera may be realized which can be marketed at a substantially reduced 
price. An example of a modified version of the viewfinder is shown in FIG. 
1 wherein the viewfinder 12 includes a lens system comprising an eye lens 
13 and a forward lens 15, and a flash socket 41 mounted upon a top surface 
thereof for receiving the flash array. 
The window 36 is provided within the cover 34 in the location vacated by 
the flash socket and being relocated upon the viewfinder 12 thereby 
positions the window 36 and the identifying characters 38 aligned thereat 
within or beneath the field of view of the operator when the operator is 
viewing the photographic scene within the viewfinder. In fact, the 
Polaroid SX-70 Land Camera may be modified for use with the instant 
invention by simply installing the instant invention in the shutter 
housing 20 and substituting a suitably modified version of a viewfinder of 
the type disclosed in the aforementioned U.S. Pat. No. 3,971,052 for the 
through the lens viewing system of that camera. Suitable modifications of 
the viewfinder would consist of adapting a portion of the lens system of 
the viewfinder 12 to bring the identifying character 38 legibly into focus 
within the viewfinder due to the close proximity of the character 38 to 
the forward lens 15. 
A typical view of the window 36 having the identifying character 38 aligned 
thereat as it is presented to the operator in the eye lens 13 of the 
modified viewfinder 12 is shown in FIG. 1(a). A pair of laterally spaced 
framing marks 17 formed upon a surface of the forward lens 15 are 
particularly useful as an aid to the operator in framing very close 
photographic objects therebetween. 
Reference is now made to FIGS. 2, 3, and 4 of the drawings wherein the 
shutter housing 20 is shown with the top cover 34, the opposing pair of 
side walls 42 and the front plate 44 removed. It is to be understood that 
other working parts such as an automatic exposure control system utilizing 
a light sensitive network providing for automatically programmed weighing 
and varying of aperature and controlling exposure intervals for a range of 
scenes most commonly encountered in conventional photographic practice 
have been omitted for clarity and only those components necessary for 
describing the operation of the instant invention have been included. 
A focusing control system comprising the focus wheel 32 and the lens 24 are 
coupled together by a coupling apparatus 45 whereby the lens 24 is 
synchronously moved by rotation of the focus wheel 32 for objective lens 
focusing through its rectilinear movement along a locus of travel between 
a distant and nearmost foci. 
The focusing control system is mounted for rotational movement upon a means 
for mounting the device 78 thereon comprising a mounting bracket 46 having 
a base 48 which may be integrally joined to an upright wall 50. The 
upright wall 50 integrally includes a pair of laterally spaced support 
members 52 and 54 which extend from an inwardly facing side 56 thereof 
above and substantially parallel with uppermost surface of the base 48 for 
rotatably supporting the focus wheel 32 and the lens 24 respectively 
thereon. 
The coupling apparatus 45 comprises a mounting pedestal 58, a shaft 60, a 
compression spring 62 and an idler gear 64. The mounting pedestal 58 is 
secured to the base 48 and has one end of the shaft 60 fixedly secured to 
the pedestal 58. The compression spring 62 is slidably inserted over a 
free end of the shaft 60 prior to the coupling of the idler gear 64 
thereto. The idler gear 64 is adapted to be manually moved longitudinally 
along the axis of the shaft 60 against the bias of the compression spring 
62 for uncoupling the focus wheel 32 and the lens 24 during the 
calibration of the focusing control system as described in detail in the 
aforementioned U.S. Pat. No. 3,914,777. The compression spring 62 acts to 
bias and thereby sustain the idler gear 64 in a coupled relationship with 
the focus wheel 32 and the lens 24. The shaft 60 includes a cylindrical 
groove (not shown) for receiving an expandable ring 66 for securing the 
idler gear 64 upon the shaft 60 thereby preventing the idler gear 64 from 
escaping from the shaft 60 under the influence of the bias of the 
compression spring 62. 
The manually rotatable focus wheel 32 is secured to the support member 52 
by a pivot screw 68 extending through the focus wheel 32 to be threadably 
connected by suitable means to the support member 52. The focus wheel 32 
is formed having a plurality of peripherally disposed gear teeth 70 for 
enmeshment with the idler gear 64 whereby the idler gear 64 is rotatably 
driven by the rotation of the focus wheel 32. 
At least one element of the lens 24 is mounted within the cylindrical bezel 
28 having a plurality of gear teeth 74 circumferentially disposed thereon 
extending longitudinally across a peripheral surface of the bezel 28 for 
enmeshment with the idler gear 64 of the coupling apparatus 45 whereby the 
lens 24 is in positive drive contact with the coupling apparatus 45 for 
movement along a locus of travel to provide objective focusing of the lens 
24. The locus of travel of the lens 24 is defined by helical screw threads 
76 circumferentially disposed upon the peripheral surfaces of the support 
member 54 whereby the lens 24 is axially displaced through the helical 
screw threads 76 rectilinearly and longitudinally along the support member 
54. 
Stated another way, the focus wheel 32 is rotatably mounted about a first 
axis spaced from and parallel with a second axis of the rotatably mounted 
lens 24 and coupled to the lens 24 by the coupling apparatus 45 rotatably 
mounted about a third axis spaced from and parallel with the first and 
second axis. The lens 24, the focus wheel 32 and the idler gear 64 are 
disposed upon the mounting bracket 46 such that they are in alignment and 
in enmeshment for rotational movement in a plane substantially 
perpendicular to their respective axes. Therefore, when the focus wheel 32 
is manually rotated, the idler gear 64 in positive drive contact therewith 
rotates, and the lens 24 also in positive drive contact with the idler 
gear 64 is synchronously moved rectilinearly along the locus of travel 
defined by the helix screw threads 76 between the distant and nearmost 
foci to obtain the sharply defined image at the focal plane of the camera 
10 whereby the camera 10 is brought into coincidence with the 
predetermined camera-to-subject distance. An aid for assisting an operator 
of the camera to know the distance at which the lens 24 is focused for a 
predetermined or preselected camera-to-subject distance is shown generally 
as a device 78 in FIGS. 3 and 4. 
The device 78 as a means for indicating at the window 36 a distance at 
which the lens is focused comprises an indicia-bearing member 80, means 
for biasing the indicia-bearing member in the direction of the window or 
supporting platform 86 and means for guiding the indicia-bearing member 
94, a drum 82, and a second idler gear 84 or means for coupling the device 
78 to the focusing control system. The second idler gear 84 is rotatably 
mounted about a fourth axis spaced from and parallel with the first, 
second and third axes. 
The device 78 is mounted upon the inwardly facing side 56 of the upright 
wall 50 adjacent to the opposing diametrical edges 35 and 37 of the window 
36 provided therefor in the cover 34 and is made active by the manual 
rotation of the focus wheel 32 to disclose the distance at which the lens 
24 is sharply focused to the operator in the window 36. 
The indicia-bearing member 80 is formed as a generally rectangular sheet of 
opaque, resilient material, e.g., plastic film or spring steel, having a 
width substantially equal to the length of the drum 82. The 
indicia-bearing member 80 is preferably preformed by wrapping the material 
around a rod and placing the rod in an oven for heat treating the plastic 
film material at approximately 200.degree. F for a predetermined period 
whereby the material takes on the configuration of the rod and is thereby 
provided with a form of memorization which operates to maintain the 
material in a normal coiled cylindrical configuration when the material is 
removed from the oven for cooling. Subsequent to the cooling period, the 
material retains the coiled configuration having the form of memorization 
and permits the indicia-bearing member 80 to automatically and 
unassistedly self-enfold or recoil back into the cylindrical configuration 
each time the material is uncoiled or unrolled. It should be noted that an 
alternative method employed for preforming the indicia-bearing member 
during the heat treating process and thereby -- provide it with the form 
of memorization is to roll the material into a cylinder and store the 
material in a tube during the heat-treating process whereby the material 
will take on the configuration of the tube subsequent to the cooling 
period. 
The second idler gear 84 is secured by suitable means to one end of the 
drum 82 to provide a unitary rotatable member. The gear 84 includes a 
plurality of peripherially disposed gear teeth 88 for enmeshment with the 
lens 24 through positive drive contact with the circumferentially disposed 
gear teeth 74 disposed on the cylindrical lens bezel 28 of the lens 24. 
The mounting bracket 46 includes a pair of laterally spaced first and 
second mounting posts or fixed members 90 and 92 respectively for mounting 
the indicia-bearing member 80 and drum 82 having the idler gear 84 secured 
thereto upon the upright wall 50. The mounting posts 90 and 92 are 
included upon the inwardly facing side 56 of the upright wall 50 and 
extend therefrom parallel with an upper surface of the base 48. 
The indicia-bearing member 80 is mounted upon the first mounting post 90 in 
the coiled configuration by sliding the coil over an unattached end of the 
post 90 into a hollow in the coil created by the removal of the rod used 
during the heat-treating process. The guide means 94 is attached by 
suitable means to an unattached end of the post 90 subsequent to the 
mounting of the indicia-bearing member 80 thereon to urge the 
indicia-bearing member 80, as it moved between the normal coiled and 
uncoiled positions, in the direction of the window 36 through its contact 
with an edge 96 of the indicia-bearing member 80. 
The drum 82 and the second idler gear 84 are mounted upon the second post 
92 to be rotatably driven by the lens 24 as it moves along its locus of 
travel between the distant and nearmost foci. The post 92 is located upon 
the inwardly facing side 56 such that the teeth 88 of the idler gear 84 
mesh with the teeth 74 of the lens bezel 72 whereby the idler gear 84 is 
rotatably driven by the movement of the lens 24 in a plane substantially 
perpendicular to the longitudinal axis of the post 92. The idler gear 84 
is retained in its location upon the post 92 by an expandable ring 98 
secured to an unattached end of the post 92 for retaining the idler gear 
84 in position for positive drive contact with teeth 72 on the lens bezel 
28. 
A leading end of the indicia-bearing member 80 is uncoiled and attached to 
the drum 82 which operates as a take-up member for the indicia-bearing 
member 80 as the indicia-bearing member 80 is uncoiled by the rotation of 
the drum 82 when the second idler gear 84 is driven in a clockwise 
direction by the lens 24 as viewed in FIG. 3. As the drum 82 rotates, the 
indicia-bearing member uncoils about the first post 90 and wraps about the 
peripheral surfaces of the drum 82 thereby placing the indicia-bearing 
member 80 in a substantially constant stress position created and 
sustained in the indicia-bearing member 80 through the tension provided by 
the form of memorization included in the indicia-bearing member 80 which 
is constantly acting to recoil that portion of the indicia-bearing member 
80 wrapped about the drum 82 upon the first mounting post 90. 
The supporting platform 86 is attached to the upright wall 50 of the 
mounting bracket 46 for engaging an underlying nonindicia-bearing side 100 
of the indicia-bearing member 80 whereby an indicia-bearing side 102 
thereof is biased in the direction of the window 36 beneath the opposing 
edges 35 and 37. The supporting platform 86 acts to bias the 
indicia-bearing member 80 in the direction of the window 36 and further 
prevents the member 80 from extending downwardly within the housing 
section 20 as it is uncoiled about mounting post 90. The supporting 
platform 86 is necessary despite the tension in the indicia-bearing member 
80 provided by the form of memorization as it is necessary for mounting 
post 92 to be displaced vertically below mounting post 90 upon the upright 
wall 50 to enable the idler gear 84 to be in position for enmeshment with 
the teeth 74 included upon the lens bezel 28 for positive drive contact 
therewith. Mounting post 90 must be located close to the top surface of 
the upright wall 50 to position the identifying characters 38 close to the 
window 36 whereby the characters 38 shall be visible to the operator in 
the window 36 of the housing section 20. Therefore, the supporting 
platform 86 is used to offset the straight line travel of the 
indicia-bearing member 80 as it uncoils and recoils upon the mounting post 
90. 
The indicia-bearing side 102 of the indicia-bearing member 80 includes the 
identifying characters 38 shown in the window 36 of the housing section 20 
in FIGS. 1 and 2. The identifying characters 38 are disposed upon the 
indicia-bearing side 102 of the indicia-bearing member 80 to form a scale 
the measurements of which are graduated so as to communicate to the 
operator through the window 36 of the cover 34 the distance at which the 
lens 24 is focused. When the device 78 is employed with a viewfinder, of 
the type disclosed and defined in the aforementioned U.S. Pat. No. 
3,971,052 and further shown in FIG. 1 as the viewfinder 12, the character 
38 in alignment at the window 36 of the cover 34 may be viewed in a lower 
portion of that viewfinder 12 (as shown in FIG. 1(a) while the operator is 
viewing the scene to be photographed therein. Therefore, the operator is 
able to concentrate on the photographic scene because the viewfinder 
contains all the information necessary for correct focusing of the lens 24 
for the predetermined camera-to-subject distance. Furthermore, the 
operator is not required to look away from the photographic scene before 
releasing the shutter of the photographic apparatus. 
The device 78 upon being coupled by the idler gear 84 to the focus control 
system may be simultaneously calibrated therewith to bring the identifying 
characters 38 presented at the window into coincidence with the distance 
at which the lens 24 is focused. For example, during the calibration, the 
idler gear 64 of the coupling apparatus 45 may be depressibly moved 
longitudinally along its axis upon the shaft 60 by applying pressure 
against the idler gear 64 whereby the focus wheel 32 is uncoupled from the 
coupling apparatus 45. Once the focus wheel 32 has been uncoupled from the 
coupling apparatus 45, the focus wheel 32 and the lens 24 having the 
device 78 coupled thereto may be independently calibrated for any 
preselected distance so as to bring the rotational orientation of the 
focus wheel 32 into coincidence with the linear focal position of the lens 
24 and the device 78. Therefore, each component of the focusing control 
system can be independently calibrated for any preselected distance and an 
appropriate character 38 indicating the preselected distance at which the 
lens 24 is focused aligned at the window 36. Thereafter, when the lens 24 
is focused for any predetermined or visually estimated camera-to-subject 
distance by manually rotating the focus wheel 32 the identifying character 
38 corresponding to that distance is presented at the window 36 of the 
cover 34. For example, in FIG. 2, the identifying character "1" indicates 
the lens 24 is located in a forward position within the focusing barrel 26 
(as viewed in FIG. 4) for focusing the sharply defined image of the 
photographic object at the focal plane of the camera for a 
camera-to-subject distance of a single measurement of distance, e.g., 1 
foot, 1 meter, etc. 
Prior to initiating exposure of a film unit (not shown) positioned within 
the camera 10 by depressing the shutter release button 22, the operator 
determines by a visual estimate or a physical measurement the distance at 
which the photographic object is located from the camera 10. Upon 
establishing that predetermined distance, the operator by rotating the 
focus wheel may adjust the lens 24 to a position within the focusing 
barrel 26 of the housing section 20 at which the lens 24 defines a sharply 
defined image of the photographic subject at the focal plane of the camera 
10. The second idler gear 84 is driven by the rectilinear movement of the 
lens 24 to a position whereby the predetermined camera-to-subject distance 
represented by an appropriate character indicating the lens 24 is aligned 
at the window 36 of the housing section 20. 
In FIGS. 3 and 4, the lens 24 is moved from a nearmost focus to a distant 
focus by the manual rotation of the focus wheel 32 in a clockwise 
direction and the lens 24 is synchronously rotated thereby in a clockwise 
direction for its rectilinear movement along its locus of travel 
rearwardly within the focusing barrel 26 in the direction of the upright 
wall 50. The second idler gear 84 and the drum 82 are driven by the 
rotation of the lens 24 in a counterlockwise direction whereby an 
appropriate portion of the indicia-bearing member 80 is released from the 
peripherial surfaces of the drum 82 and recoiled upon post 90 by the form 
of memorization of the indicia-bearing member 80 acting synchronously with 
the rotation of the drum 82 to recoil the released material automatically 
about the post 90 without any further assistance. As the member recoils 
upon the post 90, numerically ascending characters relating to the 
changing locations of the lens 24 as it moves from the nearmost to the 
distance focus are presented at that window 36. When the character 38, 
indicating that the lens 24 is properly positioned within the focusing 
barrel 26 to define the sharply defined image of the photographic object 
for the predetermined distance is presented at the window 36 the operator 
is apprised that the lens 24 is sharply focused for that predetermined 
distance. 
For movement of the lens 24 from the distant focus to the nearmost focus, 
the focus wheel 32 is manually rotated in a counterclockwise direction 
whereby the lens 24 is also driven in a counterclockwise direction for 
rectilinear movement of the lens 24 forward within the focusing barrel 26. 
The second idler gear 84 and the drum 82 are driven by the rotation of the 
lens 24 in a clockwise direction (as viewed in FIGS. 3 and 4) and the 
rotation of the drum 82 pulls the indicia-bearing member 80 in the 
direction of the drum 82 whereby the indicia-bearing member 80 partially 
uncoils and the uncoiled portion is taken up or wound about the peripheral 
surfaces of the drum 82 during which numerically descending characters 
indicating the changing positions of the lens 24 as it moves from the 
distant focus to the nearmost focus are presented in the window 36 of the 
cover 34. 
It should be noted that the device 78 enables the distance scale included 
upon the indicia-bearing side 102 of the indicia-bearing member 80 to be 
substantially expanded by simply substituting a smaller diameter gear for 
gear 84 and reducing the size of the drum 82 whereby the ratio between the 
gear 84 and the lens assembly 24 is changed to increase the space between 
adjacent characters making it possible for larger characters to be used 
for improved readability. 
Reference is now made to FIG. 5 of the drawings wherein there is shown an 
alternative embodiment of the instant invention. In this embodiment, the 
indicia-bearing member 80 is stored in the coiled configuration within a 
tube 104 secured upon the inwardly facing side 56 of the upright wall 50. 
The tube 104 extends forwardly in a direction away from the inwardly 
facing side 56 above and parallel with the base 48 of the mounting bracket 
46 and includes a slot 106 extending longitudinally within the tube for 
threading one end of the indicia-bearing member 80 therethrough for 
suitable attachment of the indicia-bearing member 80 to the drum 82. The 
slot 106 further enables the indicia-bearing member 80 to pass 
therethrough as portions of the member 80 are transferred to the drum 82 
during the uncoiling procedure and to be received in the tube 104 during 
the recoiling procedure. The guide 94 is attached by suitable means to the 
tube 104 or may be integrally included thereon for directing the 
indicia-bearing member 80 in the direction of the window 36 as previously 
described. 
It is to be noted that it is the form of memorization provided for in the 
indicia-bearing member 80 which enables the indicia-bearing member 80 to 
be unattachably stored within the tube 104 wherein the indicia-bearing 
member 80 is free to automatically recoil or self-enfold upon itself 
automatically as the lens 24 is moved by the manual rotation of the focus 
wheel 32 from the nearmost to the distant focus. upon itself automatically 
as the lens 24 is moved by the manual rotation of the focus wheel 32 from 
the nearmost to the distant focus. 
Reference is now made to FIG. 6 of the drawings wherein there is shown 
another embodiment of the instant invention. In this embodiment, the 
second idler gear 84 and the drum 82 are mounted for rotation upon a 
mounting post 110 such that the second idler gear 84 is in position for 
positive drive contact with the focus wheel 32. The indicia-bearing member 
80 is mounted in the coiled configuration upon a post or fixed member 112 
in the vicinity of the previously mentioned post 92. A leading end of the 
indicia-bearing member 80 is attached to the drum 82 whereby the 
indicia-bearing member 80 is partially uncoiled and recoiled to be 
taken-up and released respectively upon the peripheral surfaces of the 
drum 82 as the focus wheel 32 is rotated and the lens 24 is rectilinearly 
moved between the distant and nearmost foci within the housing section 20 
to a position therein at which the lens 24 is sharply focused at the focal 
plane for a predetermined camera-to-subject distance. It is to be noted 
that a reversal in the mounting positions of the second idler gear 84 
including the drum 82, and the indicia-bearing member 80 upon posts 110 
and 112, respectively, may be conducted without substantially altering any 
of the components of the device 78 as the relative direction of rotation 
of the focus wheel 32 and the second idler gear 84 remain the same at that 
hereinbefore described for operation in the preferred embodiment. 
Therefore, the direction in which the indicia-bearing member 80 moves for 
transferring portions of the indicia-bearing member 80 between the 
laterally spaced posts 110 and 112 for presenting an appropriate 
identifying character 38 at the window 36 and indicating the distance at 
which the lens 24 is sharply focused, remains substantially the same. That 
is to say, the only difference between the embodiment disclosed in FIG. 6 
and the preferred embodiment lies in the fact that the indicia-bearing 
member 80 will recoil automatically as the lens means 24 is moved by the 
rotation of the focus wheel 32 from a distant focus to a nearmost focus 
and uncoil as the lens means 24 is moved from the nearmost focus to the 
distant focus whereas the reverse is true in the performance of the 
indicia-bearing member 80 in the preferred embodiment. 
It will be apparent to those versed in the photographic art that in all 
embodiments of the instant invention, a unique means is provided for 
aiding an amateur photographer in determining the distance at which the 
lens 24 of the camera 10 is focused. 
In each of the embodiments the instant invention enables the operator to 
concentrate on the photographic scene during the focusing of the lens 24 
for a predetermined camera-to-subject distance for the operator has within 
his field of view all the information for proper focusing of the lens 24 
and is not required to look away from the photographic scene before 
releasing the shutter. The instant invention may be coupled to the 
focusing system of a new camera during the production thereof or coupled 
thereto in an appropriate model currently in use as an improvement thereof 
and is particularly adapted for use in a compact, folding type camera as 
the device does not increase the overall dimension of such a camera. 
It is apparent that by installing the simple, relatively inexpensive device 
of the instant invention into a camera, an amateur photographer will be 
constantly apprised of the necessity for focusing the lens at an optimum 
camera-to-subject distance for flash photography. Inasmuch as the 
manufacturer of the camera generally selects an appropriate distance 
therefor, such flash exposures taken with a camera having the device 
installed will always be taken at an optimum distance by rotating the 
focus wheel until the identifying character corresponding to the suggested 
appropriate distance for flash is aligned in the window of the housing 
section thereby assuring that the lens assembly is properly focused to 
provide relatively improved reliability in flash photography. 
In the ambient mode of operation, the device of the instant invention 
greatly enhances the opportunity for the amateur photographer to obtain 
sharply focused results with an inexpensive camera, particularly in the 
case where the camera is designed for use with slower speed films or 
design conditions requiring settings where only a limited depth of field 
is available. By accurately measuring or by visually estimating the 
camera-to-subject distance with substantial precision, the amateur 
photographer may manually adjust the lens assembly to a position 
corresponding to the camera-to-subject distance by simply rotating the 
focus wheel whereby an identifying character corresponding to the measured 
or estimated distance is aligned in the window of the housing section 
thereby assuring sharply focused results may be achieved within a scope of 
the ability of the operator to accurately measure the distance from 
camera-to-subject. 
The device is located on the shutter housing section of the camera at a 
location at which the image of the identifying character, aligned at the 
window of the shutter housing section, may lie within the field of view of 
the viewfinder whereby the operator may view the scene to be photographed 
and simultaneously focus the lens assembly to define a sharply defined 
image of the photographic subject at the focal plane of the camera for the 
predetermined camera-to-subject distance. Such an arrangement further 
serves as a reminder to the operator of the distance at which the lens 
assembly is focused. If the setting is obviously in error, it will be 
obvious to the operator and the proper correction may be made before the 
camera's shutter is released. 
However, it will be apparent to those versed in the photographic art that 
the device may assume a variety of positions other than its present 
position upon the camera to cooperate with viewfinder of another type 
whereby an image of the scale may be visible in or beside the field of 
view thereof depending upon the model of camera with which it is used 
without departing from the inventive concept. Such an arrangement could 
also serve as a reminder to the operator of the distance at which the lens 
is focused. 
While the device is described in the embodiments as a means for indicating 
to the operator the distance at which the lens is focused, it should be 
apparent to those skilled in the art that the device may be employed as an 
indicator for other settings used in the operation of a camera such as a 
manually operated exposure control setting whereby the device would 
indicate to the operator the size of the diaphragm opening. 
The invention may be practiced or embodied in still other ways without 
departing from the spirit and essential character thereof. The preferred 
embodiment described herein is therefore to be considered illustrative and 
not restrictive, the scope of the invention being indicated by the 
appended claims and all variations which come within the meaning of the 
claims are intended to be embraced therein.