iiililiili^ @ EuroPean Patent Office ^-S Office europeen des brevets (fi) Publication number : 0 661 584 A1 12 EUROPEAN PATENT APPLICATION (2j) Application number: 94309881.4 © int. ci.6 : G03B 15/05, G03B 19/07, G03B 13/12 (22) Date of filing : 22.12.94 (§) Priority : 23.12.93 US 178388 @ Inventor : Clark, Peter P. 129 Meadow Lane Boxborough, MA 01719 (US) @ Date of publication of application Inventor : Sorli, Duncan C. 05.07.95 Bulletin 95/27 11 Jonathan Lane Chelmsford, MA 01824 (US) @ Designated Contracting States : DE ES FR GB IT NL (74) Representative : Skone James, Robert Edmund GILL JENNINGS & EVERY @ Applicant : POLAROID CORPORATION 549 Technology Square Broadgate House 7 Eldon Street Cambridge, Massachusetts 02139 (US) London EC2M 7LH (GB) @) Lens assembly incorporating a photo-ranging system. (57) A plurality of fixed focus exposure lenses are mounted in a turret (42) for manual selection of a desired focus. Each exposure lens (34) in the turret (42) is combined with a pair of ranging lenses (26,28) for movement therewith which direct light beams to converge at the sharpest subject focus distance of the exposure lens. 00 S CO LU Jouve, 18, rue Saint-Denis, 75001 PARIS 1 EP 0 661 584 A1 2 This invention is related to a camera for close-up ferent from the focal length of another exposure lens; photography using a photo-ranging system to insure at least two ranging systems, the ranging sys- that the subject to be photographed is properly fo- tems including a source of light directed to a pair of cused. The ranging system is used in combination light focusing ranging lenses, with at least one of the with a selected one of a plurality of fixed focus lenses 5 film exposure lenses being mounted in fixed relation- mounted at the front of the camera. ship between one of the pairs of light focusing lenses, Cameras having the capacity to take close-up each pair of focusing lenses combining to focus photographs are not new. An example of a camera beams of light from the light source to converge at the used for close-up photography is the Acmel Macro sharpest subject focus distance of the related expos- Auto V6 camera manufactured by Acmel Corporation 10 ure lens mounted therebetween; and of Tokyo, Japan which involves a high complicated an adjuster for locating a desired combination system involving focal beams and a plurality of de- of a pair of light focusing lenses and a related expos- tachable lenses for different focal lengths. Each de- ure lens in operative position to take a photograph. tachable lens is designed for a single subject dis- This invention typically incorporates a plurality of tance. The resulting camera serves its purpose but is 15 exposure lenses in a turret mounted on the front of altogether too complicated for easy use by a camera the camera. The turret is mounted to rotate about an operator. It is both bulky and heavy, weighing about axis generally perpendicular to a line extending from 4 1/2 pounds. the focal point of the exposure lens to the centerof the The use of converging light beams from a camera exposure lens itself (i.e., the optical axis of the expos- to determine a proper subject to camera distance is 20 ure lens). Each of the plurality of exposure lenses is old art as disclosed in U.S. Patent No. 3,416,426 of a different fixed focal length and magnification, which is specifically incorporated herein by refer- from the other exposure lenses. The selected focal ence. The theory disclosed therein and in other liter- lengths listed subsequently are believed to be most ature provides a light source reflected from spaced frequently desirable for typical close-up photography apart mirrors through a lens board to converge at the 25 for which this camera is designed. subject of the photograph. This technique is useful Each exposure lens in the camera is combined where several parameters remain constant, in partic- with a pair of combination ranging light lens and ular, one of the constants is flash photography. With prisms which are located on the turret diagonally flash photography the duration of exposure is set and across from each otheron each side of the associated the only other variables are the exposure aperture 30 exposure lens. A combination of said transversely and the focus of the lens. mounted prism-lenses and ranging lights are perma- U.S. Patent No. 4,777,501 discloses a single pair nently focused and oriented to direct beams of light of laser ranging lights of different wavelengths which intersect the axis of the exposure lens system. mounted to project converging light beams at the focal The two converging light beams may be observed vis- point of a single fixed focus exposure lens of the as- 35 ually at the sharpest subject focus distance of the ex- sociated camera. posure lens system. The photographer may simply U.S. Patent No. 4,914,460 discloses a single pair observe the impinging beams of light from the two of light sources each of which projects a plurality of transversely mounted ranging lights as they impinge light beams in a particular pattern. The pattern is dis- on the subject. A single spot of light existing on the played on a surface which allows an observer to de- 40 subject formed by the two converging light beams in- termine the topography of the surface and its dis- dicates the subject is in focus through the exposure tance from an associated camera. The camera is lens system. Two spots of light or a non-circular or ob- mounted equidistant between the two light sources. long, pattern indicates the subject is out of focus. Get- U.S. Patent No. 5,142,299 discloses an under- ting the subject in properfocus is achieved by moving water camera mounted between a pair of light sourc- 45 the camera and/or rotating the turret to align a differ- es. The light sources project light beams to converge ent exposure lens together with their associated rang- at the focal point of a single fixed focus lens system ing light lenses and prisms. of the associated camera. Each pair of ranging lights is coordinated with a What is missing from the prior art is a camera for single fixed focus exposure lens such that conver- close-up photography having more that one focal 50 gence of the light beams of the ranging lights occurs length available to a user combined with a plurality of at the sharpest subject focus distance of the associ- ranging systems to insure proper focus of the subject. ated exposure lens. The photographer may manually According to the present invention, we provide a select a desired focus distance by selecting the ap- camera having more than one film exposure lens with propriate exposure lens and selection is made by ro- each such lens having a related ranging system, com- 55 tating the turret. The combined pair of lenses for di- prising: recting the ranging light beams are fixed in place on at least two exposure lenses, each of the ex- the turret and automatically move into operative pos- posure lenses having a fixed focal length which is dif- ition as the turret stops at the selected exposure lens. 2 3 EP 0 661 584 A1 4 Objects of the invention not understood from the beam focusing lenses and exposure lens combination above and the scope of applicability of the present in- into a desired position. It will be observed that the vention will become apparent from the detailed de- flash units 38, 40 remain stationary in opening 3 while scription to follow taken in conjunction with the ac- each set of three lenses shifts into operative position. companying drawings in which like parts are desig- 5 That is, there are five different exposure lenses 34 nated by like reference characters. which may be adjusted into operable position by ro- Fig. 1 is a perspective view of a camera having a tating knob 44 and each lens 34 has a different fixed plurality of exposure lenses and ranging light focal length. Each exposure lens 34 is supported in lenses mounted for selective use on a turret ac- combination equidistant between a pair of light focus- cording to this invention; 10 ing ranging lenses 26, 28. Each pair of ranging lenses Fig. 2 is a fragmentary perspective view of the 26, 28 is coordinated with its associated exposure turret, light and lens orientation of the camera of lens 34 such that the directed beams of light 30, 32 Fig. 1; converge at the sharpest subject focus distance of the Fig. 3 is a fragmentary sectional view of the gen- associated exposure lens 34. For convenience, light eral orientation of the camera adjustable turret, 15 beams 30, 32 are circular in their projection and at the lens and lighting combination of the invention; focus of the associated exposure lens 34, the beams and converge to a single circular pattern. Accordingly, the Fig. 4 is a block diagram of the manual select camera operator views the subject to be photograph- switch and turret position control of the strobe ed through an eyepiece 48 oriented with a viewing lights in the close-up camera of the present in- 20 optical system 50 and a pair of mirrors 52, 54 such vention. that the operator sees the subject to be photographed This invention includes a camera 10 having an along a viewing path coaxial with the optical axis of upper housing 12 and a lower housing 14 as shown the exposure lens 34.