US1799879A

US1799879A - Multiple-opening diaphragm for photographic cameras

Info

Publication number: US1799879A
Application number: US379177A
Authority: US
Inventors: Wittel Otto
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1929-07-18
Filing date: 1929-07-18
Publication date: 1931-04-07
Anticipated expiration: 1948-04-07

Description

April 7, 1931.

O. WITTEL MULTIPLE OPENING DIAPHRAGM FOR PHOTOGRAPHIC CAMERAS Filed July 18, 1929 FIQ l 18 ATTORNEYS.

Patented Apr. 7, 1931 UNITED STATES PATENT OFFICE o'r'i'o wrrriu, or aocnas'raa, new man, assrenon 'ro nasrm zonal: comm,

. or aocrmsraa, new

you, a conroaa'rron or NEW YORK manna-ornate DIAPHRAGM iron rno'roenarmc cums Application filed July 18, 1929. Serial No. 379,177.

. This invention relates to photo aphyand more particularly to diaphragms or use with photographic objectives. One object of my invention 'is to provide a'diaphragm structure which is thin and compact and which is provided with a plurality'of apertures whlch open and close simultaneously and to the same extent. Another object of my invention is to provide a multiple diaphragm having a plurality of very thin diaphragm leaves which are adapted to lie close together. Another object of my invention is to provide a plurality of diaphragm leaves normally spring pressed in one direction but being adapted to be moved opposite direction by means of a cam. Another object of my invention is to rovide a smooth working diaphragm whic requires a minimum effort to move and which includes friction reducing elements between the cam and diaphragm leaves. Another ob'ect of my invention is to provide a dup ex diaphragm which is adapted to fit into a focusin objective mount. Still anotherobject o my invention is to provide a diaphragm structure havin a plurality of leaves which may be adjuste by a. pair of friction reducing elements which, in turn, may be moved through a cam; and other objects will appear from the following s ecification, the novel features bein particularly pointed out in the claims at t e end there f.

The focusing mechanism which carries the objectives and the diaphra structure is substantially the same as the ocusing mechanism shown in my'U. S. Patent 1,690,607, for Focusing objective mount for cameras, patented November 6, 1928. For the details of the focusing mechanism reference may be had to this patent. Coming now to. the drawing wherein like reference characters denote like parts throughout:

Fig. 1 is a top plan view of a diaphragm structure constructed in accordance with and embodyin a preferred form of my invention removed or an objective focusin mount;

Fi 2 is'a similar view but wit the'parts in a iflerent position;

Fig. 3 is a section through a duplex ob-j.

jective focusing mount equipped with the diaphragm shown in the. first two figures, parts of the diaphragm being omitted for the fact of clearness Fig. 4 is a fragmentary perspective view of a. portlon 0f the setting cam and the antifriction elements used in connection with my dia hragm; I

- ig. 5 is an enlarged fragmentary view showing a single pair-of diaphragm leaves and the actuating rollers removed from the lens barrel; and

Fig. 6 is a fragmentary front plan view of the diaphragm setting member of the focusing mount. I i

In certain color processes a plurality of color records are made throu h separate objectives on different areas 0? film and it is for making such color records that the pres ent invention is particularly directed.

An optical equipment for such color work may comprise a air of matched objectives 0 and 01, these 0 jectives be' mounted in similar lens mounts 1 and 2 w ich are carried by the

annular members

3 and 4 mounted in the barrel 5. This barrel may be moved back and forth for focusing the'objectives through the threaded connection 6 with the barrel 7, a focusing scale being arranged on the bevelled portion 8 of a rin 9 which is equippedwith a flange 10 to be astened-to a support by screws passing through the apertures 11-." So. far the structure is quite similar to the structure of my above mentioned focusing objective mount patent.

For color work light rays may enter along' the line L and may be reflected by the surfaces R and R1 of the prism P, surface R being partially reflecting so that the light rays are divided and pass through the objectives 0 andOl alon the lines L1 and L2. For color work filters 1 and F2 may be placed in front I Referring to Fig. 5 the diaphragm D which lies between the lens elements of objective 0 may comprise a pair of

similar plates

12 and 13, plate 12 having an opening 14 therein and plate 13 having an openmg 15, these openings both, in the present instance, being round. There is a second pair of openings in these two plates, 16 in

plate

12 and 17 in plate 13. These openings are'larger than the openings 14, 15 and are provided solely for clearance. The diaphragm blades 12'and 13 are both pivoted upon a stud 18 and each of the

blades

12 and 13 havebent-up

lugs

19 and 20 to receive the ends 21 and 22 of a spring coiled about the pivot 18 and exerting a pressure in the direction shown by the arrows in Fig. 5.

This spring pressure naturally tends to separate the blades'12 and 13 and therefore tends to reduce the opening in the diaphragni D. H v I I To limit the outward movement, of'these blades there is a cam 23, as best shown in Figs. land 2, this cam being in the form of an annular member which is free to turn in a recess in plate '25. The ring 24, carrying thecam surfaces 23 (of which there are two in the present instance), may be turned by means of 9. lug or projection 26 which extends through an arcuate slot 27 in the annular member 28 which supports aportion of the objective mount. The end 29 of member 26 engages an aperture 30 in the annular adjusting ring 31 which, as best shown in Fig.

' 6, is provided with a pointer 32 which may be brought opposite an indicating member 33 on the diaphragm scale 34 to lndicate the quantity of light admitted by the aperture.

As best shown in Fig. 6 the annular membe? 31 has a knurled edge by which it may be turned and the ring 31'moves with the objective mount as it is moved to focus the objectives.

The cam surfaces 23 form stops which limit the movement of the

shutter blades

12 and 13 in thefollowing manner. As best indicated in Fig. 4 the cam surfaces 23 are adapted to contact with friction reducing elements 36 which may com rise small rollers having short shafts 37 w ich may extend-down into guiding slots 38 which are cut into the Slipporting plate 39. These rollers are alike and are free to turn so that as the ring 24 is turned the. cams will be moved and the rollers may move in and out with respect to the center of the objectives.

As the rollers move away from each other the springs 22 and 21 thrust the shutter leaves 12 and 13 apart and as they move towards each other. the blades are moved against the pressure of the spring and the aperture D is opened permitting more light to ass. o faronlyone' diaphragm opening I) has beendescribed. The second diaphragm opening D is identical with the first opening comprising a second pair of blades 52 and 53 pivoted upon a single stud 58 which is arranged opposite to stud l8 and operable in the clearance opening formed 'by the

large apertures

16 and 17 in the

dia hragm blades

12 and 13. Since the seon pair of dia- 1 phragm blades 52 and 53 operate in exactly moved. Each roller, of course, contacts and actuates one diaphragm blade of each pair of diaphragms so that the openings D and D are not round but are elongated. With highly corrected lenses itis not possible to detect 7 any difference in definition between a round diaphragm and a diaphragm opening of the type herein shown although theoretically such an opening is not as desirable as a round one. It is possible that some diflerence in re-- sults might be detected from extremely poorly correcte lenses although I have never tried to use such lenses in my present mount. 7

Having thus. described'my invention, what I cla1m as new and desire to secure by Letters Patent is:

1. In a diaphragm for photographic objectives, the combination with an apertured support, of means for altering the a erture in the support includin a pa r of b ades, a pivot upon which the bfiides are mounted, a sprin tendingv to move the blades in op 0- site directions about the pivot and a cam or limiting the movement of the blades under the influence of the spring.

'2. In a diaphragm for photographic objectives, the combination with an apertured support, of means for altering the aperture in the support including a pair of pivoted blades, a cam for moving the blades, and an anti-friction blades. a

3. In a diaphragm for photographic objecti'ves, the combination with an apertured support, of means for altering the aperture element between the cam and in the support including a .pair of pivoted blades, a cam for moving the blades and an anti-friction element between the cam and blades comprising a roller adapted to lie between and contact with the blades and cam.

4. In a diaphragm for photographic objectives, the combination with an apertured support, of means for altering the aperture in the support inclu'ding a pair of pivoted blades, a cam for moving the blades,'and an anti-friction element between the cam and blades comprising a guided roller, said roller having engagement with the camand blades.

5. In a diaphragm for photographic ohjectives, the combination with an apertured support, of means for altering the aperture in the support including a pair of pivoted blades, a spring tending to move the blades in one direction, a cam adapted tolimit the movement of the blades under the influence of the spring, said-cam comprising an annular member movable on the apertured support.

1O 6. In a diaphragm for photographic objectives, the combination with an apertured sup ort, of means for altering the aperture in t e support including a pair of pivoted blades, a spring tending to move the blades in one direction, a cam adapted to limit the movement of the blades under the influence of the spring, said camcomprising an annu lar member movableon the apertured sup port and having a plurality of cam faces, one

ace being adapted to serve a limiting etc for a pivoted blade, whereby each blade is separately controlled through the cam,

'6". in a diaphragm for photographic ohjectives, the combination with an apertured support, of means for altering the aperture in the support including a pair of pivoted blades, a spring tending to move the blades in one direction, a cam adapted to limit the movement of the blades the influence of the spring, said cam comprising an annu lar member movable on the apcrtured su; port and having a plurality out cam faces, a plurality of anti-friction devices between. the cam faces and the diaphragm blades Whereby the blades may be positioned by the cam faces through the anti-friction devices,

8. In a diaphragm for photographic ob jectives, the combination with an apertured support, of means for altering the apertures including pairs of pivoted blades two for each aperture, means for positive?! moving the blades in one direction inclu ing cams and rollers and springs for moving the pairs of blades in an opposite direction,

455 9. In a diaphragm for photograph jectives, the combination with an apertured support, of means for altering the apertures including pairs of pivoted blades two iier each aperture, means for positivel moving so the blades including cams, and r0 lers contacting with the cams, each roller being:

adapted to contact with one blade of en pair of pivoted blades whereby the bile may be moved together and to a like extent, Signed at Rochester, New York, this 15th day of J uly, 1929.

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