SU13735A1 - Device for optical alignment in a film projector - Google Patents

Description

It is known to use rotating mirror drums for ontic alignment in film projectors with continuous feed. In the proposed device, a mirror drum with mirror-like mirrors stably reinforced by it and a rotating opaque disk with a spiral cut designed to eliminate simultaneous images of parts of two frames from the screen are used.

In the schematic drawing of FIG. 1 is a side view of the device; FIG. 2- disk with spiral cuts.

The proposed device consists of a rotating drum 7 with a diameter of 265 mm. Along the circumference of the drum 7, mirrors a, b, c, size 25x25.W “are installed, each, in the amount of thirty-two pieces, located stepwise on the surface of the drum, while each mirror forms a small leg of a right-angled triangle composed of two radii from the center of the drum to the ends of the mirror. The mirror drum 7 is linked by a worm gear with a driving drum 4 having thirty two teeth, i.e. promotion tape 3 at each turn of eight frames. The ratio of the heart rate is 4: 1, thanks to what

during the advancement of one frame of tape 3 - the mirror drum 7 rotates 1/32 of a turn.

By the action of the leading drum 4, the tape 3 is moved, uniformly passing the frame window of double height in the beam of the light source 1 collected by the capacitor 2. Reflected from one of the mirrors of the drum 7, the beam of rays is directed through the lens 6 to the prism 8 with full internal reflection, rejecting i.e. image frame tape on the screen. To eliminate the design of two frames on the screen at the same time, a rotating opaque disk 5 (Fig. 2) with a cutting frame 9, installed between the frame window and drum 7 and linked to the last worm gear with a ratio of 32: 1, was applied. for the distance of one frame, the disk 5 makes one revolution, passing through the hole 9 to the mirror of the drum 7 an image of only one frame.

The subject of the patent.

A device for optical alignment in a film projector, consisting of a rotating mirror drum, characterized in that the reflector mirrors

are arranged on the drum surface in steps, in such a way that each Mirror forms a small leg of a right triangular triangle composed of two radii drawn from the center of the drum to the ends of the mirror, and in order that two frames are not projected on the screen at the same time a rotating opaque spiral disc 5 is installed.

figure 1

FIP 2