US1962356A

US1962356A - Optical system for projecting machines

Info

Publication number: US1962356A
Application number: US663111A
Authority: US
Inventors: Mihalyi Joseph
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1933-03-28
Filing date: 1933-03-28
Publication date: 1934-06-12
Anticipated expiration: 1951-06-12

Description

June 12, 1934. J. MIHALYI 1,962,356

OPTICAL SYSTEM FOR PROJECTING MACHINES Filed March 28, 1933 anormqa/ Patented June 12, 1934 PATENT OFFICE OPTICAL SYSTEM FOR PROJECTING MACHINES Joseph Mihalyi, Rochester, N. Y.;' assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New York Application March 28, 1933, Serial No. 663,111 Claims. (CI. 88-24) This invention relates to projectors and more particularly to means for adjusting the elements of a projection system relative to each other. One object of my invention is to provide a simple 5 inexpensive and efiicient means for adjusting a reflector relative to a light source and relative to a condensing system. Another object of my invention is to provide a simple adjustment by which a reflector may be regulated axially and eccentrically with respect to a light source. An-

other object of my invention is to provide a single threaded connection between a reflector unit and a support through which a reflector may be moved both to and from a light source and eccentrically with respect thereto and other objects will appear from the following specification, the novel features being particularly pointed out in the claims at the end thereof.

Coming now to the drawing wherein like reference characters denote like parts throughout;

Fig. 1 is a fragmentary view through a lamp house and optical system construction in accordance with and embodying a preferred form of my invention; I

Fig. 2 is a fragmentary sectional view showing the reflector in elevation;

Fig. 3 is a perspective view of the reflector unit removed from the lamp house.

The reflector and optical system construction in accordance with my invention may be employed in any case where it is desired to project a beam of light. 7 Such a' beam of light can be advantageously used in connection with a motion picture projector, in connection with a projector for lantern slide work, or in connection with any other machine in which a collimated beam of light is required.

As a specific embodiment of my invention 1 have shown an optical system of a simple type used in connection with a lamp house suitable for motion picture or slide projection work.

In Fig. 1 there is a support or lamp house 1 carrying a base 2 having a lamp 3 supporting a grid filament 4 such as is well known. The lamp 3 and 5-. the base 2 are preferably of the pre-focus type as is also well knownso that the filament 4 will always occupy a fixed position with respect to the is so positioned with respect to the lamp that the axis passes through the center of the filaments 4. In Fig. 1 the axis of the condenser elements and filament is indicated by the dot and dash line A.

Opposite to the tubular extension on the lamp house there is a second tubular extension 10 which is axially arranged with respect to the axis A and which is internally threaded at 11. I This tubular extension forms a support for the reflector unit which is broadly designated by the numeral 12. As best shown in Fig. 3, the reflector unit 12 comprises a tubular member 13 having a knurled ring 14 on the outside and having a ring 15 formed upwardly from the tubular part 16 a suflicient distance to carry a thread 1'7. The ring 15 is not concentric with respect to the tubular member 16 and in Fig. 3 the distance (a) from the thread to one side of the ring is considerably less than the distance (b) from the thread to the other side of the tubular mount 16. In other words, the ring 15 is an eccentric ring so that the thread 17 is eccentric with respect to the reflecting unit as a whole. Thus when the reflecting unit 12 is turned by means of the knurled ring 14, the reflector 19 is moved both 30 to and from the .lamp filament 4 and the axis of the reflector 19 is moved parallel to the axis A of the condenser unit eccentrically with respect thereto.

The reflecting element may consist of a con- 35 cave mirror surfaced with silver as is customary in projecting machines and this mirror is held onto the reflecting unit 12 in any suitable manner.

In projecting systems where the'lamp filament 9o 4 is fixedly mounted with respect to the base and where the condensers are fixedly mounted with respect to the base it is desirable to move a reflector only a very short distance to and from the lamp and a very short distance to and from the axis of the condenser so that when slight variations'in the position of the filament 4 with respect to the lamp base 2 may be taken care of.

It is also desirable to move the reflector a comparatively slight distance about the axis A since it is desirable, as indicated in Fig. 2, to adjust the reflector into a position in which the reflected lamp filaments 4 appear to lie between the actual lamp filaments 4, thus making a comparatively solid square area of brilliantly illumisingle adjustment as above described adequately takes care of properly focusing the lamp filaments for most efiicient use.

With an optical system as above described the set screw 20 may be released after a new lamp has been placed in the lamp house and the knurled ring 14 may be turned so that the reflector will move to and from the filaments 4. The threads 17 and 11 are comparatively fine threads so that at each revolution of the reflecting unit 12 the reflector 19 moves a comparatively short distance along the axis A. At the same time the reflector 19 is moved eccentrically with respect to the axis A and when the reflector filaments 4 are in the correct position with respect to the filaments 4 the set screw 20 may be tightened to hold the reflector in the desired position.

It will thus be seen that I have provided an extremely simple adjustment for a reflector by which movement in one direction actually takes care of an adjustment in two directions. The eccentric ring which I have shown in the drawing permits the reflector 19 to move a distance sufiicient to take care of the proper focusing of the commercial type of pre-focus lamp when inserted in a pre-focus base of the commercial varieties now obtainable.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In an optical system for projection purposes, the combination with a lamp having filaments, a condensing lens associated therewith and a reflector adapted to reflect the lamp filaments, said reflector comprising a unit including a threaded annular member carrying said reflector eccentrically mounted with respect to said annular member, a threaded mount for the annular member,

whereby the reflector may be moved through the threaded mount with respect to the lamp filaments.

2. In an optical system for projection purposes, the combination with a lamp having filaments, a condensing lens associated therewith and a reflector adapted to reflect the lamp filaments, said reflector comprising a tubular device having a reflector and a threaded area eccentrically positioned with respect to each other, a threaded member fixedly mounted with respect to said lens, and adapted to receive the threaded area of the reflecting unit whereby the reflector may be moved eccentrically and to and from said lamp upon said threads.

3. A reflecting unit for optical systems comprising a tubular element, a concave reflector mounted therein, a threaded ring carried by the tubular element, said threaded ring being eccentric with respect to the tubular element and reflector.

4. A reflecting unit for optical systems comprising a tubular element, a reflector mounted inside of said tubular element and coaxially therewith an eccentric ring carried by the tubular element and a thread on the eccentric ring.

5. In an optical system the combination with a support, of a lamp fixedly mounted with respect to said support, a threaded opening in said support having a fixed relation to said lamp, a reflector unit including a reflector, and an eccentric ring having a fixed relation to the reflector, said eccentric ring including a thread adapted to engage the threaded opening in the support whereby said reflector may be moved in two direct-ions with respect to said lamp on said threads.

JOSEPH MIHALYI.