SU1295359A1 - Method and apparatus for motion-picture projection - Google Patents

Abstract

The invention relates to optical instrument making and allows improving the quality of film projection by increasing the importance. In the intermittent movement of the film 4 in the film channel 5, using the jump drum 6, the illumination system scans the frame in the projection area and the image is projected by the lens 8 onto the screen 15. - a mirror with a mirror 10 translucent parts of the previous and subsequent frames. The rotation of the mirror 10 around the optical axis of the lens 3 is carried out by the cam 13 acting on the pusher 11. The mirror 10 is returned to its original position by means of the counter spring 14. 2 cps f-ly, 1 ill. c (L tsD CD cl with SP QD

Description

The invention relates to optical instrumentation, specifically to film projection technology.

The purpose of the invention is to improve the quality of film projection by increasing the illumination, as well as increasing the useful luminous flux.

The drawing shows a device for implementing the proposed method of film projection.

The device consists of a source of light 1, a condenser 2, which provides uniform illumination in the frame window of 3 frames, intermittent moving film 4 in the film channel 5 by means of a jump drum 6 of the intermittent motion mechanism (not shown). The device also contains a one-blade mirror obturator 7, a projection main 8 and an additional 9 lenses, a compensating mirror 10, a pusher 1, which causes the compensating mirror 10 to rotate relative to the axis of rotation 12 with a cam 13, kinematically connected with the mechanism of continuous motion of a film 4 as well as an opposing spring 14, leading the mirror 10 to its original position. The device projects images of film 4 frames onto screen 15.

A device for implementing the method works as follows.

The tape 4 is intermittently advanced in the film channel 5 with a projection frequency that is currently 24 frames per second using an intermittent motion mechanism (not shown) and a jump drum 6. The projector's projection system consisting of a light source 1 and condenser 2, provides for the transmission of the frame at the projection site, i.e. in the frame window 3. At that, 3/4 period T occurs the projection of the still image using the main projection lens 8 onto the screen 15. Then 1/4 T, when the frame changes, the single-blade mirror obturator 7 overlaps the projected image through the main projection lens 8. Translucent portions of the previous and subsequent frames reflected by the mirror blade of the obturator 7 using an additional lens 9 and a compensating mirror 10 of motion of the film 4, the projection

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They are guided to the screen 15 at the place of the projected 7 stills of the previous frame projected before the overlap of the light flux by the shutter 7.

The compensating mirror 10 operates as follows. At the time of the frame change, i.e. the beginning of the motion of the film 4, the cam 13, kinematically associated with the intermittent motion mechanism (not shown), acts on the push rod 11, which rotates the compensating mirror 10, allowing the screen image to be kept fixed during the next frame change. At the end of the frame change by moving the film 4, the still frame is projected using the main lens 8, since the blade of the mirror obturator 7 does not block the flow through the lens 8. The compensating mirror 10 returns to its initial state with the spring 14, as the pusher 1I does not It acts on the mirror 10 at the moment with the help of the cam 13.

Claims (2)

1. A method of film projection, which consists in projecting a picture of a frame onto a screen from an intermittently moving film frame in a movie canape, while changing the frame of the previous to the next one, block the luminous flux of the frame window, which in order to improve the quality of film projection by increase in illumination, when changing the frame in the frame window, they project the parts of the previous and next frames. 2. A device for film projection, xg containing a lighting system successively installed along the optical axis, a film channel with a frame window, a shutter, a projection lens, and a mechanism for pre-moving film movement, characterized in that it increases the effective light flux. mounted by an additional projection lens optically conjugated to the frame window through a reflecting surface made on the blade of the obturator located at an angle to the optical eskoy axis and kompensato5 0 312953594 A rum made in the form of a mirror. The lance is spring-loaded, and its other end, set at an angle to the optical one, interacts through the pusher with the cube of the additional projection curtain, kinematically connected to the lens, with the possibility of turning the intermittent movement of the ki , with one end of the grain film.