DE394030C - Cinema with optical compensation of the image wandering - Google Patents

Description

GERMAN EMPIRE

ISSUED APRiL 12, 1924

REICH PATENT OFFICE

PATENT LETTERING

- JVr 394030 - CLASS 57a GROUP 37

(E 29648 Vl] ₅₇ O?)

Ernemann -Werke, AG in Dresden. Cinema with optical compensation for the wandering of images.

Addendum to patent 393026.

Patented in the German Empire on February 8, 1923. Longest duration: August 8, 1940.

In the patent 393026 is an improvement lighting and those for the image bean Demonstration cinematograph with optical stands.

Compensation has been specified. The beam path may first be explained

wise such apparatus will continue to grow. From the crater of an arc lamp

perfected when the there described at / t is carried out with the aid of a spotlight mirror Sp

Another relationship, a real image in the entrance hatch E _1,

between the compensation elements for the fen, the opening of which "corresponds to the dimensions of the film

304030

bildfcs is similar and which is at the focal point of the lens system L ₁ . The rays directed through this axis-parallel incident at D ₁ on one of the two distributor disks, which are inclined at 45 ° to the optical axis, and whose pivot points are attached to the side of the beam path, and are reflected vertically downward by the reflective parts of the same, so that at S _{1 they} become one about an axis

ίο arrive at S ₁ oscillating plane mirror, the size of which is adjusted on both sides after the image wandering in the image window at F. From the oscillating plane mirror at .Sj, the rays are _{thrown onto the lens system L 2} , the refractive power of which is selected so that an enlarged image of the entrance hatch at E _{1 is designed} in the image window F and through the oscillating movement of the mirror S ₁ with the film image through the Window is brought down, the height of which is twice the height of a film frame.

The two distributor disks each have a mirror coating on one half, while the other half lets the light rays pass through unaffected, and they are inserted into the beam path in such a way that while the reflecting half of one reflects the rays as it rotates, the non-reflecting half of the other reflects the Rays unaffected. If a film image has arrived at the lower edge of the image window in this way, the effects of the distributor disks change and the illuminating beam cone is tracked to the film image by the oscillating mirror S _2. The we-; effect of the distributor disk D ₁ in connection with the oscillating mirror S ₁ and that of the ver; disk D ₂ in connection with the oscillating mirror S ₂ alternate with each other. The image window F is in the focal plane of the lens system L.,: As a result, the beam path behind this is again axially parallel. The beams then pass to the distributor disc D \ and - after being reflected thereto - to the oscillating mirror S _'v by the pivoting movement of the film image in the window is optically compensated. After being reflected by this mirror S ', the rays pass unhindered through the distributor disk D \ and hit the lens system L ₄ , which, in conjunction with the lens system L _3, causes the film image to be enlarged on the projection screen. The mode of operation of the distributor disks U ₁ and D ' ₂ in analogous connection with the oscillating mirrors S \ and S''corresponds to that of the lighting compensation.

The optical compensation just described works particularly smoothly with regard to the standing of the projected images when the center lines M ₁ , M ₁ and M ₂ , M _{2 of} the compensation system of the lighting and the imaging are in certain positions relative to the assigned lenses L ₂ and L. _{Ä be} brought. These two center lines intersect the optical axis of the entire arrangement, which has been bent as a result of repeated reflections, at three points each; for lighting compensation in A ₁ , B ₁ and Cj ₁ for image compensation in A ₂ , B ₂ and C ₂ , of which A ₁ , B ₁ and A ₂ , B ₂ are to be called the outer intersections. So that the present optical compensation works particularly well, according to the invention the two outer intersection points ^ ¹ I ₁ and B _{1 of} the center line M ₁ , M _{1 should} lie on the bent optical axis at a distance from the assigned lens L ₂ , namely in front of it, which are once (for ^ ₁ ) equal to half the focal length, the other time (for B ₁ ) equal to three times the amount of half the focal length of the lens L ₂ . Correspondingly, the outer intersection points A ₂ and B _{2 of} the center line M ₂ , M ₂ lie in the image compensation on the bent optical axis at distances from the assigned lens L ₃ , namely behind it, which are once (for A ₂ ) equal to half the focal length, the other time (for B ₂ ) are equal to three times the amount of half the focal length of the lens L ₃ .

The conditions are particularly favorable for the execution if the focal lengths of the lenses L ₂ and L _x are equal to each other and if their mutual spacing is made equal to double the focal length, the film path then being in the common focal plane in a manner known per se F of L ₂ and L _{n is placed} between them.

Claims (1)

Patent claim: Demonstration cinema with optical compensation of the image movement according to patent 393026, characterized in that the outer intersection points (^ ₁ , B ₁ ) of the center line (M ₁ , M ₁ ) of the mirror system for lighting compensation with the optical axis of the apparatus in front of the second condenser subsystem (L ₂ ) are at distances, one of which is equal to half the focal length, the other equal to three times the amount of half the focal length of this subsystem (L ₂ ), and that the outer points of intersection (A ₂ , B ₂ ) of the center line (M ₂ , M ₂ ) of the mirror system for image compensation with the optical axis of the apparatus behind the first imaging system (L ₃ ) are at distances, one of which is equal to half the focal length, the other equal to three times the amount of half the focal length of this subsystem (L ₃ ) is. 1 sheet of drawings.