SU728106A1 - Device for automatic matching of phases of obturators of motion-picture projector and motion-picture camera - Google Patents

Description

The invention relates to film technology.

A device is known for automatic combining the phases of the shutters of film projection and kinfilms. devices containing photosensitive elements, light sources / ce ro actuator, control circuit and code elements 1.

In the known device, the stator of the synchronous electric motor of the drive of the film projector is attached to the body so that, with N. ELICI, there is a mismatch in the film holders of the film project; and movie cameras can be rotated with a special servomotor. Together with the stator, the rotor of the electric projector of the film projector is rotated, which leads to a change in the position of the shutter of the film projector relative to the shutter of the camera. The stator is rotated until the sensors, related to the shutters of the film projector and the movie camera, do not give a signal that their positions coincide and do not turn off the servo drive,.

This is the most common. closer to the technical essence and the achieved result to the described invention.

The disadvantage of the known device is that the stator is always rotated to one side and the stator is turned off.

to the position of agreement about the bturators, the greater, the greater the angle

mismatch obturators.

The aim of the invention is to increase speed. / Pel- is achieved by the fact that in the device containing photosensitive elements, light sources, servo drive, control circuit code elements, one of which is made in the form of a half disk, the second code element is made in the form of a disk with a sector cut.

FIG. 1 is a schematic representation of the obturators, code elements and photo-branch elements; in fig. 2 - scheme

servo control; on

Fig. 3 (a, b) shows the location of the code elements of the film projector and the movie camera for cases of mismatch AND voltage plot, which explain the operation of the control circuit. The device contains a coding element of the camera / made in the form of an opaque half disk 1, mounted on the same shaft as the obturator 2 of the camera and located between the light source 3 and the photosensitive element 4, the code element of the film projector is made in the form of an opaque disk 5 with a sector cut 6, mounted on the same shaft with the shutter 7 of the movie projector and located between the light source 8 and the photosensitive element 9, Both code elements are oriented relative to their shutters and photosensitive lementov so that overlapping shutters FAE occurs at the time the coincidence, passers spinning disk sectorial notch 6 film projector 5 and the trailing edge 10 of the code by cameras poludiska.1 GOVERNMENTAL respective photosensitive elements (photosensors). The servo control circuit has two inputs to which signals from photosensitive elements are received, and three outputs — two dp reverse control of the servo motor and the third for giving a signal to stop the servo at the moment of matching the shut-off phase. The control circuit contains three logic elements AND 11, 12, and 13, an inverter 14, and a differentiated 1 st coil 15, the device operating as follows. When the cinema camera and film projector electric motors are turned on and they reach synchronous speed, the mutual position of the shutters and, therefore, the code elements is established, but it is random and the shutters are generally not phased. Depending on the mutual position of the shutters, the sector cut-out b of the code disk 5 of the projector can walk past your photosensitive element or into that when the photosensitive element of the film is lit (Fig. Pro),. or when it is dark (fig. 36), the signals of the photosensitive elements are washed at the inputs of the control line and, depending on the possible cases described mutual: the location of code elements 5 and 1, signals are generated at the corresponding outputs that turn on the servo motor that turns the stator of the film projector in the side alignment of the phases of the shutters along the shortest path. When the phases of the shutters coincide, a signal arises at the third output, turning on the servo drive. A more detailed write-off of the operation of the control circuit is illustrated by voltage plots given in dp of two cases of phase mismatch, where U, are the pulses of the photosensitive element of the camera; Uj - pulses at the output of the inverter 14; Uj- pulses at the output of the differential RC-chain 15; Od -, pulses of a photosensitive element of a film projector; Us is the pulses at the output of Out1 for the case shown in FIG. Pros and Out2 for the case shown in FIG. 36, Ugpulse at the output of the Exit, In steady state, from the photosensitive elements enter the inputs B, and B, the signals of a rectangular shape and and U, the duration of which is determined by the design of the sector-cut-off code elements. The signal of the photosensitive element of the film projector U is fed to all elements And 11, 12, and 13, and the signal of the photosensitive element of the camera And is fed to the elements And 11 directly, to the element And 12 through the inverter 14 and to the element And 13 through the differential R C-chain 15 . . In the case when the photosensitive element of the camera is illuminated, the signal coincides with the signal U. As a result, at the output of the element 11, a signal is generated that turns on the servo drive in the desired direction. St. The torus of the electric motor of the film projector begins to turn, as a result of which the pulse VJ begins to shift to the left to the leading edge of the pulse and, B, the moment of combining the pulse Id with the leading edge of the pulse and a, chzo. is the phase alignment moments, at the output of the element And 13, a signal is turned off, turning off the servo. In the case when the photosensitive element of the camera is dimmed, the signal Uj coincides with the signal and. As a result of the coincidence of the output of the element 12, a signal is generated that turns on the servo in the opposite direction to the previous one. The stator of the electric motor of the film projector starts to turn, as a result of which the pulse Od begins to shift to the right to the leading edge of the pulse U, At the moment of combining the pulse Cd with the leading front of the pulse of the output element And 13, as well. in the first case, a signal arises that turns off the servo. The invention makes it possible to reduce the time for matching the phases of the shutters of the film projection and filming apparatus, and thereby significantly save film consumption.

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Claims (1)

Claim A device for automatically combining the phases of shutters of film projection and filming apparatus, containing photosensitive elements, light sources, a servo drive, a control circuit and code elements, one of which is made in the form of a half-disk, characterized in that, in order to improve performance, the second code element made in the form of a disk with a sector cut.