SU23084A1 - Cinema projector with uniform film movement and optical alignment - Google Patents

Description

The invention is a further development of a film projector with uniform film motion and optical alignment described in patents No. 8547 and No. 18437. A device for synchronizing the motion of a film and compensating lenses is proposed.

In FIG. 1 shows a side view of a film projector equipped with the proposed device; FIG. 2 is the same, top view; FIG. 3-scheme of the device; FIG. 4-view of the compensator in front; FIG. 4 is the same side view; FIG. 5-plate with guide chutes, side view; Fig 5 is the same, front view; FIG b-obturator. The numerical designations in the drawing and in the text correspond to the designations used in the description of patent No. 18437.

In the projector described in the above patents, the primary image of the frame continuously moving in the window is already fixed and located approximately at a double focal length from the window. With full synchronization of the frame and the compensator lens (with a perfectly fixed primary image), an imaginary right passing through the centers of the compensator, the designed frame and the primary image must rotate in compensation around the center of the primary image, as around its axis, during compensation.

In the proposed device in place of this imaginary line is located the rod 105 (Fig. 4), which engages with the perforation of the projected frame. If this rod, which rotates around a fixed axis 100, will convey movements: to a film strip in plane A A, and to a compensator in plane BB (with which the planes AA and BB are parallel) so that the center of the projected frame and the center of the lens are all the time the distance, respectively, from the points of intersection of the planes of their movement and the geometric center line of the rod / 05, it is obvious that a full compensation of the frame movement in the plane CC, parallel to the AA and BB planes of the frame and compensator and passing through the geomet matic center of rotation of the rod 105. The position of the still picture in the plane CC depends on the sizes and ratios of distances frame and the compensator to centers of the rod 105,

The proposed fixture consists of two rods 105 (Figs. 1 and 2) that can freely rotate on the fixed axis 100 fixed in the tide 1a with the aid of the head 101 and the cutting 104, Each rod 105 has a wipe with a slot in which the finger 106 of the leg goes the compensator 19 (figs. 4 and 4}. The second finger 106a of the same leg runs in the guide disk 107 of the B3 disk. At the other end of each rod 105 there is a swiveling hinge 108 in which lever 109 (fig. 1 and 2) rotates with a grapple, having two teeth /// and a finger 110. The latter walks along the guide chute 112 of the 11S plate ( u. 5 and 5), which is screwed to a side door for the tape.

Unlike the former versions of the projector, here the drums 21, 21a are made for five frames. The gear ratio of gears 25, 26 is 5: 2 and the ratio of helical gears 29, 30-1: 1. At the end 117 of shaft 28 (Fig. 2), a shutter is installed to destroy diffuse light from a non-compensating compensator, structurally no different from the obturators of conventional apparatuses, but with such a cutout shape 120, as shown in FIG. 6. The eccentric 115 (fig. 1) can, using a handle not shown in the drawing, freely rotate around the axis 116 and thereby pull the tape upwards.

When the shaft 31 rotates (Fig. 2), during which one frame passes through two frames, the fingers 106a (Fig. 4) of the compensators 19 slide in the respective grooves of the BZ disks and thereby give the compensators oscillatory movements in the guides O. At the same time, the other fingers 106 of the compensators impart rotational-oscillatory movements on the axis 100 to the rods 105, so that the grabs (when moving in the working direction) alternately uniformly pull the frame currently projected for its perforation. Coupling and uncoupling of the grabs with the film is due to the action of the fingers 110 (Fig. 1; C2), which run in the guide grooves 112 of the plate 113 (Fig. 5). For this purpose, the grooves 112 are given such a shape that the finger 106 from the upper (or lower) position during its reverse movement could not get into the groove from which it had just left, but would move in an ellipse in one direction. While moving one compensator up, the grab does not have a tape also up, and at the same time the second compensator returns from top to bottom to its original position, and its grapple, not touching either the tape or another working grab, moves also down. At the moments of transferring the tape from one grab to another, they must have the same direction and approximately the same speed of movement, which is achieved by an appropriate selection of the outlines of the guide grooves of the disks 36 (Figs. 1 and 2). The range of oscillations of the compensators is coordinated with the height of the stroke of the guide grooves 112 in order to avoid the impact of the finger 110 o the top and the bottom of the part. Thus, alternately appearing primary images in the plane of the CC (Fig. 3) are projected onto the screen with two fixed lenses 18, the crestal which are fixed on the axis b (Figs. 1 and 2). The drum 21 feeds the tape, forming a lower loop; The grabs alternately and continuously pull it through the window, forming the upper loop, and the drum 21a feeds the tape into the upper cassette. If the frame is not in the frame, then by rotating the eccentric 115 around the axis 116 (Fig. 1), the tape is pulled back by an integer number of perforations upwards; this is done seamlessly, since the teeth of the grabs are so bevelled that they allow free one-way movement of the tape up even during the engagement.

The subject matter of the invention.

A device for synchronizing the motion of a film and compensating lenses in a film projector described in patent No. 8547, characterized by the use of two identical rods 105, which perform rotational-oscillatory movements around the fixed axis 100 and provided with their cuts for the fingers 106 of the compensators 19, and at the ends hinges 108 for rotating levers 109 carrying teeth /// for gripping the perforations of the reel and the fingers 110 moving in the guide grooves 112 of a special outline of the plate 113 attached to the b Eye door for filmstrip.

to the dependent author's testimony of A. V. Mikhailov

No. 23084