DE1447480C - Cinematographic projection device - Google Patents

Description

The invention relates to a cinematographic projection device, which consists of a device for driving of the film and an unwinding and winding device, a projection light source ,. one periodically between the light source and the film insertable diaphragm, an optical system, means to to change the projection frequency of the images by acting on a gripper and from film drive devices, consists.

It is already a camera for recording motion pictures with different, predetermined gear counters and with automatic adjustment of the aperture cross-section of the diaphragm to the given lighting conditions, became known, in which the camera in addition to the devices for gradual Change the number of turns and the opening cross-sections of the diaphragm separate facilities for changing the number of gears in the fast and for automatic adjustment of the opening cross-section the aperture has the changed exposure times.

This known camera is a device for recording motion pictures and not for projecting the same.

A cinema projector with an electric motor drive for two image speeds has also become known, in which the change in the frequency of the image projection electrically by means of a pole-changing Motor is made, the number of poles in relation to the sequence of images to be switched stand.

Furthermore, a device for controlling the frame rate during film playback has become known, in which the change in the frame rate by an electrical and electromagnetic Effect takes place.

Finally, it is a device for frame rate control became known in the movie playback, at which the frame rate with uninterrupted Operation of the device is changed discontinuously and each change within a Time interval of the order of magnitude of an obscuration period of the aperture takes place. In this previously known Device special control elements are provided, which during each individual longitudinal movement of the gripper influence the gripper in a predetermined manner in such a way that it engages with the film and transport either performs a movement perpendicular to the plane of the film or none such movement. This is intended to keep the movie during

cannot be transported further during this period of longitudinal movement.

The present invention has set itself the task of providing a cinematographic projection device To create the type mentioned at the outset, in which by means of a mechanical actuating device simultaneously and synchronously to the speed of the film transport rollers and the corresponding gripper can be acted on without changing the closure or the wing panel or its effect and without changing the motor speed to change the frame rate or to zero do.

According to the invention, a cinematographic projection device, consisting of a device for driving the film with an unwinding and winding device, a Projection light source, a diaphragm that can be introduced periodically between the light source and the film, an optical system, means to adjust the projection frequency of the images by acting on it to change a gripper and made of film drive devices, which is characterized is that a multi-profiled cam, which is periodically in the Film perforation engaging, under elastic spring tension interacts gripper, is axially displaceable by an actuating device in such a way that in the individual positions of the actuating device the profiles on the gripper for vertical up and down movement with different Acting frequency and that the actuating device via joint parts with a pivotable Plate with drive wheels and gears is connected in such a way that the speed of the driven thereby Transport rollers for further transport of the film of the respective position of the profiles of the cam disk is adapted to the gripper.

With the projection device according to the invention, it is possible, in addition to projecting at normal speed at will, the cinematographic images at a slow speed, e.g. B. project five or six images per second, sharp and without flicker. The interest of one Slow motion projection is known which requires an in-depth examination of the cinematographic images and the Movement by lengthening the observation of interesting scenes made possible with the photographic Projection is comparable. There are already certain measures to achieve a slow motion projection has been proposed, but these are mostly a change in the system for periodic coverage of the images without reducing the speed of the film, see above that the slowing down of the projection is accompanied by a very unpleasant flicker, which is none enables sharp observation and also tends to reduce the brightness of the projection.

In the projection device according to the invention, the speed of the shutter disc is at keep all projection frequencies when changing the frame rate, thereby reducing the change the image frequency does not cause any loss of luminosity.

With reference to the drawings, the subject matter of the invention is to be used as an example of a preferred embodiment are explained in more detail.

F i g. 1 is a diagrammatic overall view of an embodiment of the cinematographic according to the invention Projection device;

F i g. Figure 2 is a longitudinal view, on a larger scale, showing part of the internal mechanisms of the device shows with a housing part removed;

F i g. 3 is a cross-sectional view of the projection apparatus taken along line 3-3 of FIG. 2;

F i g. Figure 4 is a section taken on line 4-4 of Figure 4. 3, which is the swiveling system for parking the film drive or to drive the transport rollers that drive the film at two speeds shows, this system being in synchronism with that contained a triple-acting cam System is driven, which periodically and with variable frequencies the gripper with the perforations of the film can be engaged or made ineffective for that gripper;

F i g. 5 is a partial view of FIG. 4 corresponding side view showing the installation and the mode of operation of the heat filter. shows which one automatically locks of the light beam and the film is brought when the drive system for a projection with slower Speed is in the neutral position in which the film transport rollers and the gripper is not driven;

F i g. 6 and 7 are a side view and a plan view, respectively, of the drive grippers of the film and of the with this cooperating triple acting cam;

F i g. 8 is a perspective view of the triple acting Cam.

The cinematographic projection device has a body or a housing, which also forms a holder for part of the mechanisms and parts, which in large part of this housing to be surrounded and protected. The housing ■ becomes simpler, more expedient and more advantageous Way formed by three main parts, namely two side shells 1 and 2 made of molded plastic

or another molding compound, and an intermediate strip 3, which is made of sheet metal or any can be other material and the shells 1 and 2 connects. «

Outside the shell! Mounted housings 1 α and 1 b (FIG. 1) are provided to protect the lamp, the fan, etc. and the mechanisms attached to the outside of the shell 1. In particular, the channel for the passage of the film and the support and pressure parts is located between parts 1 a and 1 b.

The shells 1 and 2 have along the three sides of their connection with the strip 3 a groove I c and la for receiving the corresponding edge of the strip 3 (Fig. 3). This creates a connection between the components of the housing. .

In extending along the open base of the components of the housing grooves le, 2c , a mounting plate 6 is attached, which carries certain parts of the projection device directly or with the help of attached holders, z. B. the motor 7, the fan 8, etc. (Fig. 2).

Another part for quick, easy and convenient assembly and proper arrangement part of the mechanisms and parts of the projection device is supported by a simple plate 9 formed from sheet metal or any molding compound, the edges of which can be bent to provide rigidity to improve the plane of the plate. This plate is in the tray 1 in any convenient manner

(Fig. 3) attached, ζ. B. by fastening screws, not shown on support approaches formed in the shell 1. The plate 9 naturally has the necessary Cutouts for the connections between the interacting elements lying on both sides of the plate Parts and mechanisms on e.g. B. for the passage of the intermediate plates 4, the role for the drive of the shutter, the axles of gears, etc.

In Fig. 2, the extension of the shaft 7 a of the motor is shown in dashed lines, which by means of a belt pulley 10 drives a belt pulley 11 seated on a drive shaft 12. The drive shaft extends approximately over the entire length of the projection device in the vicinity of the mounting plate 9.

The shaft 12 is mounted in two bearings 13 and 14, of which the bearing 13 is a roller bearing while das.Lager 14 is a plain bearing with a ball joint, xvelches an automatic alignment of the shaft on the bearing 13 causes.

One sees in particular in FIGS. 1 and 3 the transport rollers 17 and 18 for the film advance. These rollers are formed in any known manner and with meshing with the film perforation Provided circumferential teeth. They sit on axes 19 and 20. The gears are also on these axes 21 attached, which together by a in F i g. 3 chain 22 shown in dashed lines are driven.

The axes 19, 20 are in the shells 1 and 2 and the mounting plate 9 with the help of plain bearings or Rings 23 rotatably mounted, which are preferably made of a self-lubricating material. the The angular position of the bearings 23 is determined by corresponding flattening of their bearing surfaces in openings the shells and the mounting plate. There is some play between the bearings and the mounting holes provided in the shells and the mounting plate, so that the bearings when installing the Align the axes by yourself. This avoids exact costly execution, wherein at the same time an excellent result is achieved.

One can also see in particular in FIGS. 2, 3, 6 and 7 the closure disk 24 of known design, which is mounted on the shaft 12 and is driven by the latter. This disk has flags 24 a on its circumference, which come one after the other in a manner known per se into the projection axis P for the images of the film. On the disc 24, a cam 25 for periodic actuation of a gripper for driving the film at a certain frequency in synchronism with the disc 24 and a triple-acting cam described below with a certain angular position are attached, so that one after the other each image in front of one of the flags 24 α comes.

At the same time, the change in the speed of the transport rollers 17 and 18 and the change in the drive frequency of the film by the gripper are carried out synchronously by means of a knurled button 26, which appears on the housing part 1b in the example shown.

For this purpose, the button 26 is fastened on a shaft 27 which is rotatably mounted in an axially fixed position with respect to the housing and exerts a double effect when it is driven. The shaft 27 runs on one side. within the housing of the device in an eccentric head 27 α . Furthermore, the bore 27 b at the end of the shaft 27 is provided with a steep internal thread, which has a certain position with respect to the eccentric head 27 α to achieve the effects described below.

With the threaded hole 27 b , the accordingly trained ends of a pin 28 cooperate which is simply inserted diametrically into the end of an axle 29. This slides in a by a nut 31 or otherwise on the mounting plate 9 attached shaft 30. On the shaft 30 eir worm wheel 32 is rotatable, which is in engagement with a worm 12 α , which cut directly into the shaft 12 or on this can be placed. The wheel 32 has on the shaft 30 .ein z. B. by einet collar 30 α the same certain axial fixed position.

There is also a triple acting on shaft 30; Cam 33 rotatably mounted, which of the wheel 31 is driven by means of pins 34. However, the cam 33 is axially displaceable along the shaft 30 namely by means of the axis 29, at the end of which it can be accessed directly by means of a screw 35 or as desired other known way is attached. With any: axial position of the cam 33 cause the pins 3 ^ always its twist.

The cam 31 shown in particular in Fig. 8 has a three-fold circumferential profile on its width corresponds to a projection of 18 frames per second). The part 33 b of the cam is circular and has germ projections. It corresponds to the non-propulsion state of the film. The part 33 c has circumferential projections in a smaller number for actuating the drive gripper with a lower frequency (in the example shown there are 3 projections, which corresponds to a projection of 6 images per second).

The eccentric head 27 α of the shaft 27 lies between the legs of a fork 36 a rigidly connected to a switching plate 36 . The plate 36 can be pivoted directly or by means of a contact surface on the shaft 2C of the transport roller 18.

The plate 36 carries axes 37 and 38 in certain angular positions. These axes pass through the mounting plate 9 into openings which allow the necessary adjustments. The axle 37 carries a gear 37a and a wheel 37b, which are firmly connected to one another. The axis 38 carries a gear 38 a.

Depending on the angular position given to the plate 36, the wheel 37 b or the wheel 38 α can be brought into engagement with a gear 39 fixedly connected to a wheel 39 α. The gear 39 and the wheel 39 α are freely rotatable on an axis 40 attached to the mounting plate 9. The wheel 39 is in engagement with an α mounted on the wheel shaft 30 41st The wheel 41 is with the wheel 32, ζ. Β. by means of the pins 34.

In an intermediate angular position of the plate 36 (FIG. 4), the wheels 37 b and 38 α are not in engagement with the gear 39, so that no transmission of motion to the wheel 42 attached to the shaft 20 of the transport roller 18 takes place. That is the neutral position.

So there are two drive options for the wheel 42 and the transport rollers, namely a drive with the normal advance speed of the film (e.g. 18 frames per second) by means of

of the wheel 38 α and a drive at a lower speed (z. B. 6 images per second) by means of the wheel 37 b and the gear 37 a.

A sliding arm 43 is hinged to an extension 36 b of the plate 36 and is guided in any suitable manner along the mounting plate 9 (FIGS. 4 and 5), for. B. in cracks and upsets 9 α of the mounting plate.

The upper end of the arm 43 is freely connected at 43 α to a double lever 44 which at 44 α in fixed position relative to the housing of the device is pivotally mounted. The three ends of the lever 44 carries a heat filter 45 of any known type. The training is made so that this filter

45 automatically comes into the projection axis P between the lamp L (shown in dashed lines in FIG. 2) and the film F when the plate 36 is in the neutral position in which the transport rollers are not operated and the film is not driven . This avoids the destructive effect of the light beam from the lamp on the immovable film.

As the film is advanced, it is driven by a gripper 46 (FIGS. 6 and 7) which has drive teeth 46 α corresponding to the pitch of the film perforations.

The gripper 46 is double-articulated in two planes, namely on the one hand at 46 b on a z. B. attached to the mounting plate 9 holder 47 and on the other hand at 46 c. The gripper is made up of several parts to enable the movements corresponding to these joints, and elastic devices 48, for example spring leaves or the like, act on the various parts of the gripper to keep it in contact with the cams that drive the film Give F the movements required at the various speeds. A synchronous connection to maintain constant contact between the gripper and the cams is also possible.

Two drive pressures act on the gripper 46 attached in this way, namely a pressure in a perpendicular one Plane that acts from top to bottom and is periodically generated by the profile of the cam 25, which in any suitable manner on the upper part of the gripper or a contact part thereof acts, and one in synchronism on the gripper in a horizontal plane through the profiles 33 α or 33 c of the triple-acting cam 33 pressure exerted. The gripper has a contact finger for this purpose

46 d , which passes freely through the holder 47 and, depending on the axial position of the cam 33, comes in front of one of the three profiles thereof.

When the motor of the projection device is running, the gripper is always given a reciprocating movement in a vertical plane with a frequency determined by the profile of the cam 25 and its speed, which are selected accordingly. The drive of the film F thus depends on the horizontal movements that are given to the gripper 46 in synchronism with the vertical movements to introduce the teeth 46 α into the perforations and the film during a fraction of the pivoting under the pressure of one of the projections. 33 a or 33 c to drive, whereupon the teeth 46 a are pulled out of the perforation by the action of the gaps between the pre-cracks and the film is not driven.

When the gripper is driven by the section 33 α of the cam, the teeth 46 α apparently come with the Perforating the film with a large frequency in

ίο intervention, and the film is driven at its normal fast projection speed (e.g. 18 frames per second). When the gripper is actuated by the section 33 c of the cam, the teeth 46 a come into engagement with the perforation of the film at a considerably lower frequency, and the film is driven at the slow speed that enables the precise observation of the images. If, however, the cylindrical portion 336 of the cam is the finger 46 d of the gripper

so opposite, no horizontal movement is given to it and the film is not driven. This axial position of the cam 33 corresponds to the position in which the heat filter 45 by the above Brought facilities in the projection axis

»S is going to make the film stand still against the effect. to protect the light beam.

May be, with respect to which indicia mounted b by simple operation of the single knob 26 on the housing part 1, to thus generate two simultaneous effects synchronized by means of a single actuation.

First, the cam 33 is moved in the axial direction by the interaction of the parts 27 b, 28 and 29, so that one of the three profiles 33 a, 336, 33 c of the cam comes in front of the finger 46 d .

Furthermore, through the interaction of the parts 27 α, 36 α, 36, the plate 36 is pivoted, which the Profiles of the cam 33 can assume positions corresponding to, d. i.e., it can use the transport rollers 17, 18 drive at normal projection speed or stop the transport rollers and the film or drive the transport rollers 17, 18 and the film at a slow speed. This synchronization of the speed of the transport rollers and the speed of the The film moving gripper enables a so to speak "normal" slow projection below Utilization of the entire luminous intensity of the lamp under the same conditions as with the fast one usual projection. Slow-speed projection is flicker-free. This will be the unpleasant oscillation or flicker effects of the process avoided which the slow motion effect by intervening in the locking mechanism. To achieve slow motion effects do not need to take recordings at very high speed, which is expensive is because this requires a greater length of film. You can also use slow motion effects when projecting without a high speed recording apparatus; d. H. with a simpler one Recording apparatus.

For this purpose 2 sheets of drawings

309 618 / Π3

Claims (5)

Patent claims: 1. Cinematographic projection device, consisting of a device for driving the FiI-mes with an unwinding and winding device, a projection light source, an aperture that can be periodically inserted between the light source and the film, an optical system, devices to adjust the projection frequency of the images by acting on them to change a gripper and from film drive devices, characterized in that a cam disk (33) provided with several profiles (33 a, 33 b, 33 c) , which interacts with a gripper (46) which periodically engages the film perforation and is under elastic spring tension , is axially displaceable by an actuating direction (26) in such a way that in the individual positions of the actuating device the profiles ao (33 a, 33 b, 33 c) act on the gripper for vertical up and down movement at different frequencies and that the actuating device ( 26) via joint parts with a swiveling plate (36) with drive s and gears is connected in such a way that the speed of the transport rollers (17, 18) driven by them is adapted to the further transport of the film of the respective position of the profiles (33 a, 33 b, 33 c) of the cam disk (33) to the gripper (46) will. . 2. Projection device according to claim 1, characterized in that the multi-profile driven cam disc (33) has a triple circumferential profile, namely a portion (33 a) with circumferential projections, the number of which corresponds to a drive frequency of the film for normal projection, a second Section (33 b) with a smooth circumference, which corresponds to a position of the non-drive of the film, and a third section (33 c) with a smaller number of circumferential projections, which corresponds to a drive frequency of the film at a lower speed. 3. Projection device according to claim 1 and 2, characterized in that an extension (36 6) of the pivoting plate (36) is articulated on an arm (43) which on its other End freely connected to one end of a double lever (44) which is at a fixed point of the housing is pivotable and carries a heat filter (45) which is in the projection axis of the Light beam arrives when the pivoting plate (36) is in the non-drive position of the delivery rolls. 4. Projection device according to claim 1, characterized in that the actuating device (26) actuates a shaft (27) which at the free end has an eccentric head (27 a) and a threaded bore (27 b) which is connected to a pin (28) cooperates, which is inserted into the end of an axially displaceable cam disk (33) bearing axis (29), the cam disk (33) being non-rotatably but axially displaceably connected to a wheel (32) driven by the drive shaft (12) and the The head (27 a) of the shaft (27) interacts with a fork (36 a) of the plate (36) which is displaceable on the axis (20) of the lower transport roller (18). 5. Projection device according to claim 1, characterized in that the plate (36) drive and Gears (37 a, 37 6, 38) or gear sets, which on the one hand with the drive shaft driven gears can be brought into engagement and on the other hand with a gear (42) are in engagement, this the transport rollers at different speeds drives and the plate (36) can be brought into a neutral position in which the transport rollers (17,18) are not driven.