MXPA00001213A - Switchable format film projection system - Google Patents

Abstract

The present invention relates to film transport systems for motion picture projectors and, more particularly, to a film projector movement that is capable of transporting film prints having frames spanning a predetermined number of perforations per frame at a specified projection frame-rate and then automatically switching to another film format having frames spanning a different number of perforations per frame as well as a different projection frame-rate, based on the detection of an encoded trigger strip on the film which carries the format characteristics of the incoming film. A controller enables the system to automatically switch between a variety of different film formats and frame-rates, on the same projector and on the same platter of film, without substantially interrupting or delaying operation of the projector.

Description

FILM PROJECTION SYSTEM WITH CHANGEABLE FORMAT BACKGROUND OF THE INVENTION The present invention relates to film transport systems for cinematographic film projectors and, more particularly, to a movement system of the film projector, which is capable of transporting publications of films in a format and then changing to another film format, without interrupting the operation of the projector, during the change. Conventional 35mm theatrical theater contz projectors employ a motor-driven chain wheel, which pulls the film intermittently through the film gate at a standard speed of twenty-four frames per second. During the period of motion of the film, a rotary shutter, driven by a constant speed motor, locks the screen to prevent blurry views. The viewing audience is not aware of these movements of darkness, due to the phenomenon known as "persistence of vision". The film is supplied to and away from the gate of the same and the intermittent chain wheel by constant speed chain rudas on either side. The intermittent movement of the film, created in the gate of the film, is made uniform by the loops of the film on either side of the intermittent chain wheel, which are held by the constant speed chain wheels. The current projectors of theaters are almost exclusively of the mechanical type. Traditionally, the simple synchronous motor drives a propulsion shaft that carries multiple propulsion gears, which actuate the shutter just like the constant speed and intermittent speed wheels, at a single speed, which corresponds to the standard speed of frames in USA, 24 frames / second. The intermittent chain wheel is driven by a device called Geneva mechanism, whose purpose is to move a complete revolution of the propulsion shaft in a ninety-degree rotation of the intermittent chain wheel, followed by a stationary period for image projection. The ninety-degree rotation of a sixteen-tooth chain wheel results in a four-hole change of frame (ie, a "downward pulse"). The four-perforation table standard was established in the late 1800s, to accommodate the projected aspect ratio of 1.33: 1 and has not changed until now. Consequently, the commercial projectors of 35 mm were designed for the downward impulse of four perforations at 24 frames / second.

While virtually all 35mm theater projectors are mechanical design, there are several special projectors on the market that are characterized by an electronic downward impulse. These designs rely on a high response from a servomotor (auxiliary motor), instead of the Geneva device, to advance the position of the film in the gate of the same. Anamorphic systems are used for the presentation of a true wide screen, which optically compresses an aspect ratio image of 2.4: 1 at 1.33: 1, into a four-perforation camera frame, during photography, and then decompresses the image during the projection. At the end of 1959, the "1.85" screen format was developed, in order to supply the surface with a "semi-wide screen view", without having to resort to the anamorphic camera and projection lenses. Approximately eighty-five percent of movies currently in circulation use the 1.85: 1 format. To achieve this projected aspect ratio, a mask is simply inserted into the opening of the projection gate. This mask covers the areas of the top and bottom of the projection frame, thus increasing the ratio of width to height of the image. As a result, the images displayed in these masked areas are never seen.

In the accompanying drawing, Figure 1 shows this very clearly. The reticulated area 64 represents the area of film that can be used, which is wasted in the 1.85: 1 projection format with a frame height of four perforations. The area represented by the number 66 corresponds to the optical analogue sound track. One solution to the problem of the wasted film area is to change to an alternative frame height standard, which supplies the same projectable area, as shown in Figure 1, but without the wasted film area at the top and bottom . One such alternate frame standard is the three-hole frame shown in Figure 2. By removing much of the area previously wasted by the mask, the same projecting area can be adjusted in three perforations of the film instead of four. . Consequently, the elimination of this "wasted" area results in a reduction in the release footage released and, therefore, the cost, by around 25%. While the format of three perforations is a step in the right direction, it is not the last in the conservation of film, since there is still some area wasted in the upper and bottom, which must be masked during the projection. Figure 3 illustrates the final frame height for the 1.85: 1 format, in that there is virtually no area of wasted film. The standard 1.85: 1 format has an established film width which is limited by the space reserved on the left side of the film for the optical sound track. This limit frame width, together with the 1.85: 1 aspect ratio, sets the frame height to 0.446 inches (11.33 mm). When a few thousandths are added for the space between figures, this height corresponds to 2.5 perforations precisely of the length of the film. The 2.5-bore descending pulse format represents a reduction in released release footage of approximately 37.5%, when compared to the standard four bore format. While film preservation and its financial impact is one of the most important emergencies at the moment, image enhancement may be even more important in the future of cinema. As new digital technologies emerge that improve the quality of the home's vision, the theater's exhibition will have to improve proportionally for the most attractive audiences. It is possible to improve the image of the theater in two ways. One is to increase the size of the frame and the other is to increase the camera and the speeds of the projection frames. Both require changes in the way in which the film is photographed and projected. 1. Growing Frame Size With the 1.85 format, it is possible to increase the size of the frame by expanding the image in the movie laterally in the area previously occupied by the analog sound track. The analog optical sound track will be replaced by redundant digital tracks. This new format is explained more fully in patent application Serial No. 08 / 646,777, filed May 8, 1996, which is incorporated herein by reference. Combining this enlarged picture with the 3-hole downward impulse, a 32% increase in image enhancement is achieved concurrently with a 25% reduction in film usage. Alternatively, by increasing the height of the frame to five perforations and the use of novel anamorphic lenses for this, the greatly enlarged format will result in a significant increase in resolution as well. However, this will result in greater use of the movie. 2. Increase of the Speeds of the Pictures of the Camera and Projection The increase of the speeds of the pictures of the camera and projection of 24 to 30 or even 48 frames / second, has been demonstrated to provide the observer with a sense of reality significantly increased. Since the image formation of the film is temporary, higher frame rates will eliminate flicker and thus allow for greater screen brightness, which would otherwise make such flicker noticeable while simultaneously increasing the perceived resolution and elimination of motion anomalies, known as "stroboscopic". Stroboscopic anomalies occur when objects move across the screen at speeds and angles so that the illusion of cinema movement is disturbed. Strobe objects seem to jump from one position to another in an unnatural way. This problem is solved by the use of higher frame rates in photography and projection. From the above, it is evident that there are several altitudes of alternative frames and speeds of projection frames, which are highly convenient for several reasons, but which have the problem of incompatibility with the existing projection systems. The successful introduction of alternative format films and the theater exhibition will require that the installations are equipped with projectors that are capable of operating in all formats. It is essential that these projection systems have the ability to project standard four-perforation films and 24 frames / second, along with alternative format films, since the anamorphic presentation of the widescreen will continue to require the full four-frame perforations. In addition, there will always be some "classic" films and others (for example advertisements for trailers and public services) that remain in the original format of four perforations. Several designs have been proposed that attempt to provide the three / four perforation downward impulse to the existing projectors. However, the fundamental problem with these designs is that they require a manual alteration of each individual chain wheel in the projector, when the format is changed in any direction. This makes these designs totally impractical due to time and labor constraints. The present invention introduces a fully automatic, down-the-pulse, downloadable projector movement / shift pattern. This movement will allow the same theater projector to show several films of alternative format in a back-to-back form, without undue attention from technicians and without hesitation in the presentation. In this way, the present invention satisfies the problem with the above designs and provides further related advantages.

SUMMARY OF THE INVENTION The present invention provides a changeable format projection system, comprising a film transport system, for transporting the films through a projector. In the discussion of the invention that follows, the word "format" refers collectively to the classification of those film characteristics that have an effect on the design of the projection system or operation of the number of projection frames (frames per second). ), the height of the frame (number of perforations), the aspect ratio of the frame (width to height) and the optical system (anamorphic, as opposed to spherical). For example, when used in a collective sense, such as in the phrase "alternative formats may be used", it attempts to be inclusive of any combination of the above characteristics. However, in some cases, the "format" can be used in a more specific reference, such as the "four perforation format", in this case it simply refers to a publication format that has frame height characteristics of " four perforations ". The term "mode" is generally used to indicate the selectable operation condition of the movement of the projector of that invention, which corresponds to the needs of the reference format. The film transport system, also referred to as a movement system of the film projector or "head", includes a plurality of chain wheels having teeth for coupling with the perforations in the film, and a movement element, which turn the chain wheels and move the film in a • ^ g ^ way from frame to frame, passing an opening in the projector. According to the invention, a control system is provided for regulating the movement element and thus maintaining or changing the speed of rotation and the position of the chain wheels, according to the format of the film, in terms of the number of perforations extended by each table and in accordance with the scheme of designated tables. In this way, the film transport system is capable of running the film in a variety of different formats on the same projector, with a minimum amount of experience required by the operator and without interruptions or delaying the operation. of the projector. In one embodiment of the invention, the film transport system includes a pair of chain wheels, one on each side of a film gate, and an intermittent chain wheel between the pair, to advance frame by frame the film by passing a opening in the film gate. The speed of rotation of the pair of chain wheels is determined by a variable speed motor, and the rotation speed and the placement of the intermittent chain wheel is determined by another motor, such as a high response servomotor. (intermittent servomotor). In this embodiment, these two motors comprise the movement element of the film transport. However, if desired, a single motor or three motors (or more) can be used as the movement element. Also, in this embodiment, a third separate motor is used to rotate a shutter blade, which is part of the mechanism of the projector, which must be maintained in a synchronous movement. Any change in the speed of the frames of the film will require a corresponding change in the rotation speed of the shutter, and, therefore, this shutter motor must be either a variable speed motor or a servo motor (auxiliary motor). . The control system coordinates the output of the variable speed motor, the intermittent servomotor and the shutter motor and is responsive to a trigger signal indicating the format of the film. For example, the trigger signal may be information that is encoded on the film strip and read by a sensor. Based on this type of trigger signal that is received, the control system can change the speed of the shutter motor and the output of the variable speed motor which, in turn, changes the speed of rotation of the pair of chain wheels, as well as the rate of advance of the frames of the movie . The variable speed motor and the shutter motor each drive a digital optical encoder ("encoder") having a transparent disk, of light weight, which has been dosed with radially spaced lines. A light source, such as a light emitting diode (LED) and a photodiode assembles the encoder disk so that, in operation, the light source projects a beam of light towards the photodiode. When turning the disc, the passage of each line of the encoder causes the beam to be interrupted and a pulse of each photodiode will be emitted. The output of these pulses makes it possible for the control system to keep track of the exact rotation position of the motor and the intermittent chain wheel and will cause the motor to accelerate, decelerate or stop at an exact position with an accuracy that is a function of the number of lines in the encoder disk. Encoder disks with 1000 lines or more are commonly used in industrial motion control. Alternatively, a disc, of non-transparent type, with radial grooves, can be used in place of the transparent type disc with radial lines. The optical encoder technology is well established and has been used for years in the motion control industry. The initial movement of the servo motor for each frame down pulse is controlled by the output of a conventional servo motor control card ("controller") in conjunction with a CPU, which is t ££ á ^^^ í% ~. ^ * í¿ & ^ t + ^ has programmed to supply the servomotor with a selection of predetermined movement profiles, which include acceleration, velocity and angular displacement in terms of the numbers of the encoder A selection of profiles is required in order to accommodate the needs of the various frame height and frame rates. This is achieved by alternating the component of the angular displacement of the movement profile and the time allowed to make the movement. The actual motion command originates from the shutter motor encoder, when the index pole passes the photodiodes. The encoder then generates a pulse, which is fed through the control card to the servomotor, to initiate an advance of the film by a frame. The servomotor also drives an encoder similar to the one described above, which continuously monitors the position of the servomotor, so it can feed digitized information with respect to the position of the film to the controller, enabling intermittent stopping of the movement of the film in the appropriate position and ensure proper registration of each frame in the film gate. If desired, redundant LED / photodiode arrays can be supplied in each encoder. The trigger signal is indicative that the film changes format, so there is a change in the _____ tt¡É _______ i____ film that has frames that extend four perforations per frame to a movie that has frames that extend three perforations per frame, or a change from a specified frame rate of 24 frames / second to 30 frames / second, or both changes together. Of course, the trigger signal may be representative of a change between many different kinds of formats and, in general, is designated to indicate when the film format in the projector changes from a format having frames that extend by a predetermined number. of perforations to a format having frames extending by a different predetermined number of perforations, or of a predetermined frame rate to another predetermined frame rate, or both changes together. The trigger signal indicates a change in the movie format that can be generated in a number of ways. In one embodiment, the trigger signal is generated electronically by a sensor coupled to the control system. This sensor can be designed, for example, to read the encoded information carried by the film as it enters the projector, to indicate a change in the format of the film. This information may be encoded on a magnetic sheet or strip, or an optically readable code, or by mechanical means or other appropriate means. Alternatively, the trigger signal can be £ É ^ ¡^^ generated manually based on the visual inspection on the film by the film operator. Other suitable means of generating this trigger signal will be apparent and the invention is not limited to the signals generated manually or electronically. Regardless of the manner of signal generation, an important feature of the invention is that the film transport system is adapted to switch between film formats, without interrupting or otherwise stopping the operation of the projector. This eliminates any delay when there is a change between the film formats, for example, different film formats can be spliced together in the same film projection system. A projection system comprises the film feed and the capture storage module for the projector. Likewise, no special experience is required to make an alteration between film formats, since the system is designed to be simple and reliable in operation, without requiring any significant training. In addition, the film transport system can be designed to be retromounted to existing 35mm projection systems, thus avoiding the high cost of replacing the entire projection system, which includes lamps, condenser, projection systems and other components . ^^^^ a ^ £ ^^^^ Other features and advantages of the present invention will become apparent from the following description of the invention taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

Brief Description of the Drawings The accompanying drawings illustrate the invention. In these drawings: Figure 1 shows a section of a movie in a format in which each frame spans four perforations, - Figure 2 shows a section of film in another format wherein each frame spans three perforations Figure 3 shows a section of film in yet another format, in which each frame is extended by 2.5 perforations; Figure 4 is a perspective view, showing the general components of the transport system of the film of the present invention, including the control components, with portions of the projector removed for clarity; Figure 5 shows a strip of the film having multiple formats suitable for use in the film transport system; ^ I ^^ ^^^^^^^^^^^^^^^^^^^^^^^^^ jijgg the ^ g Figure 6 is an elevation view of a sprocket with rear bracket and an optical / digital encoder, both of which are driven by a servomotor; Figure 7 is an elevation view, taken along line 7-7 of Figure 6, showing an optical encoder disk; Figure 8 is a schematic layout of the main components of the film transport system; and Figure 9 is a flow chart, showing the communication paths between the main components of the film transport system.

Description of the Preferred Modality The present invention is incorporated in a film transport system, generally named by the reference numeral 10, for transporting a film 12 through a projector. As shown in Figure 4, system 10 film transport includes two chain wheels, constant speed, comprising a sprocket 22 supply and a sprocket 24 of the rear support located on opposite sides of the film gate 26. An intermittent chain wheel 28 is placed immediately below the film gate 26 and between the two chain wheels, 22 and 24, of | g | g¡ ^^ j ^ f | constant speed, to advance the film 12 intermittently, frame by frame, through the film gate in the usual manner. Thus, the intermittent chain wheel 28 accurately records each frame of the film 12 with the gate 26 of the film in the standard E.U.A. regime, twenty-four frames per second or in any other frame rate that may be desired. The film gate 28 also includes an aperture 29. A projection light source 96 and a shutter leaf 99, rotated by a shutter motor 90, are also illustrated. The slack of the film 12, in the form of loops of loose film, is provided between the chain wheel load 22 and the damper film 26 and between the wheel intermittently chain 28 and the sprocket 24 rear support for prevent the breaking of the movie. The film transport system 10 also includes a movement element, comprising a variable speed motor 30 and a servo motor 32. This variable speed motor 30, in this embodiment, can also be a servomotor. However, as explained below, the variable speed motor 30 may also be a three speed motor, or it may supply additional speeds, as desired. The intermittent servomotor 32 must be a high-response servomotor and all rotating components comprising an intermittent unit must gá ^^^ ft? ^ g ^^^^ gfiStí ^^^^ gftggj ^^ tói ^^^^^^^^^^ g exhibit a minimum of polar moments of inertia with in order to enable the chain wheel to be accelerated and decelerated in the regime required by the intermittent duty cycle. Alternatively, it is considered that the movement element may comprise a single motor with mechanical or other means for driving and changing the speed and position of the chain wheels 22, 24 and 28. The variable speed motor 30 rotates an output shaft 34, which extends from each end of the engine. One end of the shaft 34 is connected for rotation to the rear support chain wheel 24. The shaft 34 also rotates an impeller wheel 36 which carries a synchronous band 38 which engages the impeller wheel 36 to the second wheel 40. This second wheel 40 is connected to a shaft 42, which rotates the feed chain wheel 22. Thus, the supply chain wheel 22 and the rear support chain wheel 24 are coupled together by the synchronous band 38 and are rotated in unison at a constant speed by the variable speed motor 30. As also shown in Figure 6, the tree 34 on the variable speed motor 30 also carries a digital / optical encoder ["encoder"] 46. Thus, the supply chain wheel 22, the rear support chain wheel 24 and the encoder 46, which are all commonly coupled to the shaft 34 of the variable speed motor 30, they are rotated at the same speed of rotation. The encoder 46, like two other encoders described below, is associated with the servomotor 32 and the shutter motor 90, each having a disk, with a light source (LED) and a photodiode mounting the disk. As explained before, the rotation of the disk causes pulses to be emitted from the photodiode. Referring again to Figure 4, the intermittent servomotor 32 also rotates an output shaft 48, which extends from each end of the servomotor. One end of the shaft 48 is connected for rotation to the intermittent chain wheel 28 and the other end of the shaft 48 rotates an encoder 52. FIG. 5 shows a section of the film 12 having a plurality of perforations 56, along from the edges of the film. Between the perforations 56 are the squares 58 which, for purposes of illustration, are separated by vertical lines 60. The section of the film 12, which is a standard 35 mm film, is shown as having different formats for its length. The left and right sections of the film 12 have a format in which each frame 58 extends through four perforations 56. The central section of the film 12 has a format in which each frame 58 extends through three perforations 58. The transition between these two formats is represented by "^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 62, the function of the lime will be explained in more detail below: Figures 1 and 2, discussed previously, show the two film formats in greater detail, Figure 4 also shows a host computer ["UCP"] 95, a motor controller 94, a motor amplifier 93 and a DC power supply 92, which, together, comprise the power / control system ("control system"). The motor controller 94 includes controllers for the motor 30 of variable speeds, servomotor 32 and shutter motor 90. Similarly, amplifier 93 of the motor includes amplifiers for each of these motors, 30, 32 and 90. Located near the entrance of the gate of the film, is a sensor 97, which is used to detect format change information, encoded in the film trigger strip 62, which is then dependent on the system of control The operation of the film transport system 10 is described below and is better understood with reference to Figure 4, in conjunction with Figures 7 and 8. For purposes of the description, it will be assumed that the film transport system 10 it is initially adjusted for the operation with a film format, in which each frame is extended by four perforations and the frame rate - '^ - "Srify ^ yr-- is the standard of 24 frames / second, followed by the subsequent change to a film format in which each frame is extended by three perforations and the projection frame rate is 30 frames / second, such that these two film formats are spliced together in the same projector system For convenience, these two film formats are referred to below as the "24-four" format and 30-three format, respectively. In this case, there will be two control cards used. One card is a "shutter driver", which serves the shutter motor, as well as the variable speed motor, and the other card is an "intermittent controller", or "servomotor controller", which serves the intermittent servomotor. Any reference to the "control system" will also include both controllers and any related software (program). At the start, the control system has been conditioned for the 24 -four format by the information delivered from the contact by the sensor 97 with a strip 62 of the open trigger or from the existence of an implicit mode in the loop. Shutter motor 90, like the variable speed motor 30, are, therefore, energized and commanded by the control system to rotate their output shafts at the appropriate respective rotation speeds, corresponding to a 35 mm film having a 24-four format. This results in the rotation of the supply chain wheel 22 and the rear support chain wheel 24, in the direction of advancement of the film, thus providing and taking equal amounts of the film 12 on the opposite sides of the gate 26 of the film and the chain wheel 28 flashing. At the same time, the variable speed motor 30 rotates the encoder 46 and the shutter motor 90 rotates the shutter 99 at 24 revolutions / second, while, at the same time, an encoder 91 rotates, at the same speed. The shutter coder 91 has been rotationally adjusted so that the passage of the index finger of the encoder disk between the associated LED and the photodiode corresponds to the projection shutter 99 which first reaches the fully closed position. With the shutter 99 closed, no light is able to reach the screen and any movement of the film in the gate 25, due to the advance of the frame, will not be perceived by the observers. The passage of the index pole causes an index pulse 101 to be generated by the encoder 91 of the shutter motor and this pulse is directed to a motor controller 94. The motor controller 94 then sends a signal 102 to the servomotor 32 to advance the film 12 by the rotational equivalent of a frame, "" '- "- ^ - ^ J» M .____. - ~> ^ * ^ - ^^ according to the profile of movement of four perforations, previously programmed, with the motor 90 of the shutter turning to 24 revolutions / second, the intermittent movement continues with an advance of • the film of four 5 perforations of 24 frames / second, until pointing out otherwise .. As this film advance, the CPU 96 is continuously looking for a signal from the sensor 97 When this change occurs, it signals the motor controller 94 to change the operating mode, 10 changing the various outputs of the motor, as required, by the entering film format. Figures 7 and 8, the sequence of events will generally be summarized as follows: 1. The control system is activated and the 15 motor controllers 94 are started 2. The implicit motion profile is loaded into the intermittent servomotor controller of the motor. CPU 95. 3. Charged at the film and frame load rates implicit in the throttle motor controller, from the CPU 95. 4. The variable speed motor 30 and the shutter motor 90 are each accelerated at a constant speed. 5. The intermittent servomotor controller reacts continuously to the index pulse once per «^^^^^^^^« ^^^^^ t ^^^^^^^^^^^^^^ gß? S ^^^^^ ßÉ? ^^ ÉÉ ^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^ revolution, generated by the encoder 91 of the shutter motor, which causes the chain wheel 28 to rotate intermittently through the motion profile loaded and causes the film 12 to advance through a frame for each received index pulse and then stop for the projection. 6. CPU 95 enters a loop, in which it continually searches for a trigger signal indicating a change in the film format and thus the operation mode. When this change occurs, the signals are sent to the motor controllers 94 to change the frame height and the frame rate, accordingly. 7. Step 5 continues without interruption until the CPU 95 encounters another format change signal, which causes the step 6 to be repeated or a "stop" signal from the sensor 97, in which it instructs the motor controllers 94 to stop the system 10.

In this way, the intermittent movement is secondary to the shutter motor 90, in terms of the frame rate and secondary to the controller 94 of the intermittent servomotor, in terms of the increase in the advance of the film. As the intermittent chain wheel 28 is driven, the film 12 is advanced through the ^^^^^^^^^^^^^^^^^^^^^^^ dßHßMßffl | ^^^^^^^^^^^^^^^^^^^^^ 26 of film at the rate of one frame for each pulse 101 of output of encoder 91 of the shutter. During this operation, the motor controller 94 ensures that each film frame is accurately positioned in the film gate 26. This is achieved in the following way. As the intermittent chain wheel 28 advances the film frame 58 in position in the film gate 26, the intermittent encoder 52 detects the position of the servomotor / intermittent chain wheel (32, 28) and, similarly, the position of the film frame 58, in terms of the number of advanced encoder lines and this information is fed to the servomotor controller 94 via the feedback signals 103. the servomotor controller 94 is then compared in its position with the ideal position defined by the command movement profile and, correspondingly, generates correction signals 102 instructing the servomotor 32 to accelerate, decelerate or stop. In this form, the film frame 58 is moved quickly in the film gate 26 and positioned with the greatest accuracy. With respect to the sequence of events described above, the power / control system, mentioned previously (control system), works in the following manner. Since the high-response intermittent servomotor 32 requires a very large energy supply in ^^^^^^^^ ßHß ^ ¡É ^ | ^^^^^^^^^^^ g ^^^^^^^^^^^^^^^^^^ very little time, it is necessary Supply the control system with 92 high output power DC power. The operation of this power supply 92 is provided by the motor amplifier 83 which, in turn, is driven by the motor controllers 94. Therefore, when it is said here that the controller 94 sends signals to the motors to accelerate, decelerate or stop, it is actually said that the controller 94 sends signals to the amplifiers 93 of the motor, which are used to dose the power from the supply of power 92 to the motors, in the necessary way to achieve the command movement the adjustment. As the film 12 continues to advance through the system 10, one of the trigger strips 82 on the film will be read by the sensor 97 in front of the film gate 26. In one embodiment, the trigger strip 62 carries information that is encoded magnetically, optically or otherwise or applied to the strip 62. Ideally, the strip 62 of the trigger is located at the junction between the two film formats, as shown in Figure 5. The information read by the sensor 97 in this case, in the form of an example, indicates a change of the film format from the 24-four format to the 30-three format, and an appropriate pulse or series of pulsesl04 is generated by the sensor 97 that corresponds to this change in format. This pulse-current 104 is amplified in an amplifier (not ^^^^^^^ --a- ^ aaSM ° - - displayed) and directed to the PCU 95, which serves as a watchdog of format changes and loads the motor controller 94 with the appropriate motion profile for change the motor output, as necessary, to meet the requirements of the new mode of operation. At the same time that the alteration of the format takes place, the change in the scheme of tables must also be achieved. The same coded trigger signal 104, which is derived from the trigger strip 62 in the film 12 is used to accomplish these tasks. The trigger signal 104 is directed to the section of the motor controller 94 which serves the shutter motor 90 and that component of the coded signal which identifies the frame rate of the projector causes the shutter motor 90 to adjust the speed correspondingly, which in this case it is an increase at 30 revolutions / second. Since the advance of the film must always be maintained in synchronism with the rotation of the shutter, as previously described, the intermittent servomotor 32 is secondary to the movement of the shutter 99. For each revolution of the shutter motor 90, an index pulse is generated by the encoder 91, which is directed to the intermittent servomotor section of the controller 94. This controller 94, in turn, sends a signal to the servomotor 32, via the amplifier 93 of the motor, to advance the film 12 through a frame 58, that in ^^^^^ g ^^^^^^^^^^^^^^^^^^^^^ ggggg ^ g ^^^^ || ^^^^^^ j ^^^^^^^ ^^^^^^^^ This case is of three perforations. In this way, the frame rate of the projector is increased from 24 frames / second to 30 frames / second, and at the same time that the frame height is changed from four perforations to three perforations without stopping the operation. It is important to note that in the three perforation format, shown in Figure 2, the centerline of the frame, from left to right, passes through the center of a film perforation 58. In the four perforation format, shown in Figure 1, however, the center line of the format bisects the space between two film perforations 56 - a displacement of half a perforation between the two formats. Consequently, the first step from center to center when changing from a four perforation format to one of three perforations should be a 3.5 perforation stage. Without this initial index movement, the projected image would be supplied with an incorrect box, in which the line separating the movie frames would appear on the screen. Next, the spacing from center to center will be constant with three perforations per frame. The film transport system 10 is designed to accommodate this displacement by an initial repositioning of the intermittent chain wheel 28 with respect to the orientation of teeth in the stopped position. This can be accomplished by programming the controller £ á & ^^^^^^^^^ 94 to start a first stage equal to half the sum of the sizes of output and input tables (in this case, (4 + 3) ¡2 = 3.5 perforations) This index step must be executed with precision in the film splice, in order to avoid an error of the frame and the need for a subsequent correction. In this way, the intermittent chain wheel 28 is reoriented to maintain the appropriate film frames in the three-hole format and all subsequent movements are in three-hole advancements. It will be appreciated that the film transport system 10 is capable of changing, not only between the two film formats described above, but between any other number of film formats. Thus, as a further example, the film transport system 10 can be configured to use the film format shown in Figure 3, which illustrates a section of the film 12, in which each frame 58 is extended by 2.5 perforations. When the transport system 10 is changing from the format of four perforations to the format of 2.5 perforations, an initial stage of 3.25 perforations ((4 + 2.5) / 2 = 3.25), followed by subsequent stages of 2.5 perforations, will be required and will be achieved in the same way as described above. Similarly, the alteration of the format of three ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Since the sensor 97 is preferably positioned in front of the film gate 26, the passage of the trigger strip 62 on the sensor 97 will generate a pulse 104 slightly before the film 12 is in the proper position for the change. Consequently, the control system must provide a delay in the process. The delay period will be determined by the distance between the sensor 97 and the film gate 26, a constant, and the current mode of operation of the system 10, as determined from the information encoded in the trigger strip 62. Because film 12 moves slower in the three perforation format, the delay period will be slightly longer. An alternative means of compensating the displacement position of the sensor 97 will be to shift the placement of the trigger strip in the film publication (ie the register) by an amount equal to the displacement of the sensor from the opening 29 of the film. In this way, the change will be timed exactly under any condition of frame height or frame rate, without requiring the inclusion of a time delay. At the time as another trigger strip 62 in the film 12 is read by the sensor 97, another pulse 104 will be sent to the controller 94 by means of the CPU 95, which will indicate all the components of the system 10 to return to the condition of operation that corresponds to the 24-hour format, as described above, or any other mode of operation that may be specified on the coded trigger strip. It is also considered that the firing strip 62 can be a sheet strip that can not be demagnetized, an optically readable key, a mechanical trigger (e.g., groove, perforation or embossing of the film) or other appropriate means. Also, if desired, the sensor 97 can be replaced or augmented by a manual switch 130 in the projector 14, to initiate a format change based on visual inspection of the film 12 by a film operator. Of course, it will be understood that when a new reel or film projection 12, which has a constant format is first loaded into the projector, the shot strip 62 can be placed at the beginning of the film strip or a manual switch 130 can be activate to command the proper operation of the projector.- Thus, in the reading of the trigger strip 62 or in the activation of a manual switch 130, the control system can make the necessary adjustments, described above, for operating the film transport system 10 in the manner appropriate for the particular format of the film 12 running through the projector. In addition, it will be appreciated that redundant encoders can be provided for each of the motors. This redundancy helps ensure trouble-free operation in the event of a malfunction of one of the associated sets of LEDs or photocells / photodiodes. The system of projection of changeable format, previously described, will allow the distributors to manufacture circulating publications in alternative formats which eliminate waste. By doing this, they will save materials and money without concurrent reduction in the quality of the image displayed to consumers. The benefits of this process go beyond the initial savings mentioned. Because the waste is limited, the publications are physically shorter and lighter. Therefore, they cost less to transport and can still be transported completely assembled and ready for projection. Currently, a 100-minute movie has 9,000 feet (2,743 meters) long and, because of its weight, it is transported in 2,000-foot (609.60 meters) reels. These reels can be joined together in the specific projector for the screen where they will be displayed. This process is called the "montage" of the movie. It can be done by people _-______ «_« "_« __._ .ti! R- - jjj nt _ ^ ..__, _ ... ^^. ^, _ M _ ^^ __ ^ > ,. experts, such as those who project it. When the theater administration decides to move that publication from another screen, it should usually "disrupt" and "re-mount" again, as it is too heavy to move easily from one projector to another. However, in the new more compact form, made possible by the present invention, the same 100 minutes will be made at only 6,750 feet (2057.4 meters) long (using film having a three perforations format) or 6,625 feet (1714.5). meters) (using a film that has a 2.5-perforation format). With this reduced length and weight, it will be possible to transport films on a single pre-mounted reel and move that reel from one projector to another without "breaking down" and "tracing" the stage. A further advantage of the film transport system 10 of the present invention resides in the ability to automatically rewind a complete system of the design, which supplies and takes the film to and from the film transport system 10, in the design systems Previously, the projection person was required to re-coil the system between the projections of each complete assembled design. Also, conventional film transport systems employ mechanical devices that prevent the film from being re-wound at high speed. The film transport system 10 of the ^^^^ ggggBgggg ^ i ^^^ i ^ _ ^^^^ this invention, however, eliminates these mechanical devices and uses a completely electronic design that prevents intermittent movement in the intermittent chain wheel 28 during the rewinding operation and, therefore, it provides a movement of the film at high speed, uniform, in reverse. The film transport system 10 can be commanded to operate in the high speed rewinding mode, by the provision of a trigger strip 62 at the end of the film 12, which, by the process described above, commands the motors 30. and 32 to rewind the film at high speed. From the above, it can be seen that different or additional film formats can be run in the film transport system 10 by the appropriate programming of the control system to identify the format or frame rate of its trigger strip code. and to provide the various engines with the appropriate commands to operate harmoniously in the recently defined mode of operation. In this way, the film transport system 10 of the present invention, among other things, can: (1) change, back and forth, between film formats having different frame heights; (2) change between formats that have different film frame speeds and (3) make any format change in the same film design 12, -rUJff ", ~ * a-t * • ^ JhafcJ * ^ JMI *" "- - ^ - <" - - < - * - * + ** * - *. automatically, without interrupting or stopping the operation of the projector 14. Never before had a simple design been proposed that would characterize or even suggest more than one of these three characteristics. 5 This combination of features must be fully applauded by film producers and directors with budgets ranging from less than one million to 100 million or more dollars. Finally there will be an ideal format available for any company. The productions with low budgets can enjoy the financial benefits of reduced publication costs and films with high budgets can enjoy the improved value of presenting larger and higher speed formats. 15 This flexibility will also be welcomed by distributors and movie exhibitors, who will have better options in bringing two or more different film formats together in the same movie design. The expenses and efforts in the distribution and exhibition of films are thus greatly reduced. Likewise, for projection purposes, little experience or training is required to carry out the change between film formats, thus making the ideal system for the operation by employees of film theaters relatively non-existent. experienced. sggg¡ ^ gt ^^^^ ^^ stt ^ t ^^ í &S? rí ^^ ^ s': tl? * r - While a particular form of the invention has been illustrated and described, it will be evident that vain modifications can be made without departing from the spirit and scope of the invention. Therefore, the invention is limited only by the appended claims. ^^^^^^^^^^^^ ß ^^^^^^^^ _ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ j ^^^^^^^^^^^^^^

Claims (23)

1. A system of movement of a film projector, to transport a film through the projector of the cinematographic film, in which this film has a series of frames and a plurality of perforations along the edges thereof, this system comprises : a plurality of chain wheels, which have teeth to engage with the perforations and to move the film through the projector; an intermittent advance mechanism, which moves the film, frame by frame, passing an aperture in the projector; an element of movement, which turns the chain wheels and drives the intermittent mechanism of advance; and a controller, which controls the movement element and is adapted to maintain or change the rotation speed of the chain wheels and to position the intermittent advancing mechanism, based on the format of the film, in terms of the number of perforations that they extend for each frame in the film or based on the speed of the projection pictures, in terms of frames per second.

2. The motion system of the film projector according to claim 1, wherein the plurality of chain wheels comprises a pair of constant speed chain wheels, one on each side of the opening, having teeth for coupling with the perforations. and to move the movie through the projector.

3. The movement system of the film projector according to claim 2, wherein the intermittent advancing mechanism comprises an intermittent chain wheel, having teeth for coupling with the perforations and for advancing the film intermittently, frame by frame, passing the opening.

4. The movement system of the film projector according to claim 3, wherein the movement element comprises: a first motor, having a rotation output for rotating the pair of constant speed chain wheels; a second motor, having a rotation output for intermittently rotating the intermittent chain wheel; and a third motor, which has a rotation output to rotate a shutter. ______ »__» _-._. !. * a * > í *. * > ?? ^ mmma ** .... .. _ ^ _ a_h .-- • ..... ^ A ^

5. The motion system of the film projector according to claim 4, wherein the first motor comprises a servomotor (auxiliary motor) and the second motor comprises also a servomotor.

6. The movement system of the film projector according to claim 5, wherein the controller controls and coordinates the first and second motors and is responsible for a trigger signal for changing the output of the first and second motors, individually, and so the 10 rotational speed of the pair of chain wheels and the placement of the intermittent chain wheel, where the trigger signal indicates when the film in the projector changes from one format, in which each frame is extended with a first predetermined number of perforations on 15 the film, to a format in which each frame is extended with a second predetermined number of perforations in the film.

7. The motion system of the film projector, according to claim 5, wherein the controller 20 controls and coordinates the third motor and in response to the trigger signal to change the output of the third motor and thus the rotation speed of the shutter, in which the trigger signal indicates when the film in the projector changes from one mode, in which the movie advances to a first 25 frame rate predetermined to a mode in which the ^. ^? a. ^! -: Sfeé., ..- j ..-...! .. Movie advances at a second predetermined frame rate.

8. The movement system of the film projector according to claim 7, in which the controller, in response to the firing signal, controls the output of the second motor, to execute a first "dosed" film advance, whose extension is determined by the frame heights of the output and input movie formats, followed by an output of successive movie-plays with an extension corresponding to the frame height of the input format.

9. The motion system of the film projector according to claim 8, wherein the firing signal is based on the number of perforations extending in each frame on the film.

10. The movement system of the film projector according to claim 9, in which the firing signal is generated automatically during the operation of the projector by electronic, magnetic, optical or mechanical means.

11. The motion system of the film projector according to claim 9, in which the trigger signal is generated manually. ^^^^^ j ^^^^^^^ _ ^^? ^^^^? ^^^^^^^ m ^^^^^ lj ^^^^^^^^^^^^^^

12. The movement system of the film projector according to claim 2, wherein the intermittent advancing mechanism comprises a mechanism in addition to the toothed chain wheel that rotates. .

13. The movement system of the film projector according to claim 12, wherein the intermittent advancing mechanism can rotate or provide a reciprocal movement to intermittently advance the film.

14. The movement system of the film projector according to claim 13, wherein the movement element comprises: a first motor, having a rotation output, for rotating the pair of constant speed chain wheels; a second motor having a rotational or reciprocal output, to drive the intermittent advancing mechanism; and a third motor, which has a rotation output to rotate a shutter.

15. The movement system of the film projector according to claim 13, wherein the movement element comprises: a first motor, having a rotation output, for rotating the pair of constant speed chain wheels; and a second motor, having a rotational or reciprocal outlet, for driving the intermittent advancing mechanism and the obturator.

16. In a projector of motion film films, a movement system of the projector, to transport the film, which has a series of frames with 10 images in them, and a plurality of perforations along the edges of the film, this The projector comprises: an intermittent advancing mechanism, to be coupled to the perforations and to advance the film frame by frame, passing an aperture in the projector; a pair of constant speed chain wheels, one on each side of the aperture and the intermittent advancing mechanism, having teeth 20 to engage the perforations and to move the film through the projector, in cooperation with the intermittent mechanism of Advance; a first motor, having a rotation output, for rotating the pair of constant speed chain wheels; a second motor, which has a rotational or reciprocal output, for actuating the intermittent advancing mechanism; a third motor, having a rotation output, for rotating a shutter; a first controller, which controls and coordinates the rotation output of the first motor, where this first controller is adapted to change or maintain the rotation output of the first motor, without substantially interrupting the operation of the projector, thereby changing or maintaining the speed of rotation of the pair of constant speed chain wheels, when the film in the projector changes from a first film format, in which each frame is extended by a first predetermined number of perforations in the film, to a second format of film, in which each frame is extended by a second predetermined number of perforations in the film; wherein the first controller also controls and coordinates the third motor and in response to a trigger signal, to change the output of the third motor and thus the rotation speed of the third motor, where the trigger signal indicates when the film in the projector change in a way, in which the movie ^ effeiM ^^^^^^ g ^ TOj »^^^^ sgg ^ | M < ^ fete advances at a predetermined first frame rate, to a mode in which the film advances at a second predetermined frame rate; and a second controller, in which, in response to the firing signal, it controls the output of the second motor, to execute a first advance of dosed film, the extent of which is determined by the heights of the frames of the formats of film 10 exiting and entering, followed by an output of successive film advancements, with an extension corresponding to the frame height of the entering format.

17. A motion system of the projector 15 films, for transporting a film through a projector, in which the film has perforations along its edges and squares between the perforations, this system comprises: a plurality of chain wheels and an intermittent movement device, for move the film through the projector; a motor element, to rotate the chain wheels and operate the intermittent motion device at selected speeds and to place ^^^^^^^^^^^^^^ g ^^^^ __? < __ ^ _ ^^^^^^^^^^^^^ jU ^ g ^^ g ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ , passing an opening in the projector; a control element, for controlling the motor element and for maintaining or changing the movement of the intermittent motion device, the rotation speed of the chain wheels and the motion of the film based on the film format, in terms of the number of perforations that extend in each frame in the film and based on the speed of projection frames, in terms of frames per second; and a control element, for controlling the motor element and for providing a first dosed movement, based on the heights of the frames of the output and entering film formats, to supply the appropriate frame of the entering film format.

18. A method for transporting a film through a projector, having a movement element that rotates a plurality of chain wheels advancing the film, and an intermittent motion device, which moves the film frame by frame, passing an aperture, which comprises determining the format of the film in terms of the number of perforations that extend in each frame in the film and determining the speed of pictures of the film in terms of frames per second, passing through the aperture, and controlling the movement element to maintain or change the rotation speed of the chain wheels and the movement of the intermittent motion device based on the movie format.

19. A method for transporting a film through a projector, which has a pair of constant speed chain wheels, which are coupled to 10 perforations in the film, to advance this film to a uniform regime and an intermittent advancement device, to advancing the film, frame by frame, passing an aperture in the projector, in which a first motor has a rotation output, which rotates the chain wheels of 15 constant speed, a second movement element has an output that places the device ' of intermittent advancement and a third engine has a rotation outlet that rotates a shutter, this method comprises: determining the height of the frame of film entering, in terms of the number of perforations extending in each frame on the film; determine a first dosing movement, based on the heights of frames of the film formats that come and go; g ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^ Determine the frame rate of the movie, in terms of frames per second, that pass through the aperture; controlling the rotation output of the first motor and the rotation speed of the constant speed chain wheels, based on the film format; controlling the output of the second movement element and the placement of the intermittent advancing device based on the first dosing movement and the entering film format; and controlling the output of the third motor and also the movement of the intermittent advance device based on the frame rate of the film.

20. The method of claim 19, further comprising generating a trigger signal that controls the output of the first, second and third engines, in which this trigger signal is based on the format and speed of frames of the film.

21. The method of claim 20, further comprising encoding the information about the film, which identifies the film format and the frame rate, and then detecting that information to generate the trigger signal. s1ß ^^^^^^ _ ^ iiiii _____ ^^^^^^^^ _ ^^^^^^^ gj

22. The method of claim 21, further comprising sending the trigger signal to a controller which, with Based on this trigger signal, it generates a second signal which controls the rotation output of the first motor.

23. The method of claim 22, further comprising supplying a plurality of shot strips in the film, at locations corresponding to a change in the film format or the frame rate, which encode the information on the strips. of trigger, the 10 which identify the format of the film or the speed of changed frames, and detect that information to generate the trigger signal.