This invention relates to a module for recording a digital optical soundtrack for a motion picture and more particularly, to a module for a contact printer that enables a recording of a positive digital optical soundtrack from a sound negative. Background of the Invention

Many techniques have been utilized to provide a soundtrack for a motion picture. In one technique, a magnetic medium similar to that used for magnetic recording tape is applied onto a motion picture filmstrip to form the soundtrack. However, this technique has disadvantages. A disadvantage is that the magnetic medium does not adhere well to the filmstrip, resulting in a relatively short film life. In addition, the magnetic medium typically used is abrasive, which erodes and degrades the magnetic playback head, thus rendering it inoperable.

Another technique includes the formation of an analog optical sound recording on the filmstrip. One such recording is known as a variable area recording. This type of recording provides a soundtrack having optically translucent or opaque areas whose width varies according to the instantaneous amplitude of the sound. During movie projection, the soundtrack is illuminated from behind by a lamp and is viewed in front through a slit by a photocell. As the filmstrip advances, the photocell receives an amount of light that varies in accordance with the varying width of the varying translucent or opaque areas of the soundtrack. The photocell produces a voltage corresponding to the light received which is then utilized to reproduce the sound. However, this type of soundtrack also has disadvantages. A disadvantage is that the characteristics of the translucent or opaque areas may change due to factors such as contaminants or surface scratches on the filmstrip. This results in noise or other sound degradation when the soundtrack is played back. In another type of optical recording, a soundtrack is configured such that it conforms to a curve that is empirically derived to provide the best compromise

between signal to noise ratio, dynamic range and frequency response. This type of soundtrack is known in the art as the "Academy" soundtrack. As is well known, however, the Academy soundtrack has disadvantages since it is only monophonic, has a relatively low signal to noise ratio and relatively high distortion. Digital optical recordings have also been used to provide a soundtrack.

Generally, such recordings are formed by converting analog sound signals to digital codes. A filmstrip is then exposed to light which is modulated in accordance with the digital codes to form a digitally encoded soundtrack on the filmstrip. Digital soundtracks have many advantages. One advantage is increased resistance to audible degradation caused by repeated use. In addition, digital soundtracks substantially reduce the amount of hiss and noise associated with analog soundtracks. As such, an increasing number of motion pictures include a digital optical soundtrack.

However, many movie theaters are not equipped to reproduce a digital optical soundtrack. Consequently, many motion pictures include an analog optical soundtrack and a digital optical soundtrack to insure compatibility with theaters having either analog or digital sound reproduction systems. Such motion pictures are manufactured by utilizing a contact printing process in a manner well known in the art. In this process, a picture negative and a sound negative having negative analog and digital optical soundtracks are processed by a contact printer to form a positive print.

Many conventional contact printers exist which do not have the capability of forming a digital optical soundtrack in conjunction with an analog optical soundtrack. It is desirable to modify such existing contact printers by adding a module which enables the formation of a digital optical soundtrack on a positive print. It is also desirable that the module be inexpensive to fabricate and easy to use. Furthermore, it is desirable that the module cause negligible wear of the positive print and sound negative so as to prolong their useful life. Summary of the Invention An add on module for a contact printer used to manufacture a motion picture, wherein a sound master having a negative digital soundtrack is placed in contact with unexposed film. The module includes a baseplate affixed to the

contact printer and first and second roller elements rotatably mounted to the baseplate, wherein the sound master contacts the first and second roller elements. The module further includes a pivot arm rotatably mounted to the baseplate. In addition, the module includes a main roller positioned adjacent the first and second roller elements and rotatably mounted to the pivot arm, wherein the film contacts the main roller at a printing point. Furthermore, the module includes a fiber optic light source which generates light for exposing the film at the printing point to form a positive digital soundtrack on the film from the negative digital soundtrack. Additionally, pressurized air is utilized to provide pressure on the sound master to maintain contact between the sound master and the film at the printing point. Brief Description of the Figures

FIGURE 1 is a view of the printer module in accordance with the present invention in a closed position. FIGURE 2 is a view along section line 2-2 of FIGURE 1.

FIGURE 3 is a cross sectional view of first member along section line 3-3 of FIGURE 2.

FIGURE 4 is a view of a light guide along line 4-4 of FIGURE 3. FIGURE 5 is an alternate embodiment of a light guide. FIGURE 6 is a cross sectional view of a central portion of a first guide roller.

FIGURE 7 is a cross sectional view of the first guide roller locked in a desired position.

FIGURE 8 is a view of the printer module in an open position. FIGURE 9 is a cross sectional view along section line 9-9 of a spring loaded pin in an extended position.

FIGURE 10 is a cross sectional view along section line 9-9 of FIGURE 8 of the spring loaded pin in a retracted position.

FIGURE 11 depicts a portion of a pivot arm in the open position and the spring loaded pin in the extended position.

FIGURE 12 depicts the spring loaded pin in the retracted position as the pivot arm rotates past a roller element.

FIGURE 13 depicts the pivot arm in the closed position wherein the spring loaded pin is extended on a left side of the roller element.

FIGURE 14 depicts the printer module affixed to a contact printer. FIGURE 15 is an enlarged view of a section of the contact printer depicting the location of the printer module. Detailed Description of the Invention

In accordance with the present invention, a printer module will be described which may be affixed to a conventional contact printer such as a Bell and Howell Model C Printer for use in a contact printing process. The addition of this printer module enables the formation of a digital optical soundtrack on a positive print by using a sound negative having a negative digital optical soundtrack. The present invention will now be explained by referring to the following description in conjunction with FIGURES 1-15. In FIGURES 1-15, like elements are designated by like reference numerals and an element which is underneath another element is shown as. dashed lines.

Referring to FIGURE 1, a top portion 10 of a Bell and Howell Model C printer having a drive sprocket 12 is shown. A printer module 14 in accordance with the present invention is affixed adjacent and to the right of the drive sprocket 12 in FIGURE 1. As will be described, the module 14 is positioned in a film path for a sound master such as an exposed and developed sound negative 16 having negative analog and digital optical soundtracks and unexposed film such as a print film 18. The sound negative 16 and the print film 18 each include sprocket holes along their edges (not shown in FIGURE 1) which mate with the teeth of the drive sprocket 12. The drive sprocket 12 is driven to rotate by a device (not shown) associated with the printer and serves to advance the sound negative 16 and the print film 18 upward through the module 14.

In FIGURE 1, a section of the sound negative 16 and a section of the print film 18 are shown positioned within the module 14. The module 14 includes a pivot arm 20 rotatably attached to a baseplate 22. The baseplate 22 includes a first guide roller 24 and a first sprocket 26 each having end flanges 28 (only one end flange is shown in FIGURE 1 for the first guide roller 24 and the first sprocket 26). The first sprocket 26 includes teeth 82 and is positioned above and

to the left of the first guide roller 24 and to the right of the drive sprocket 12. The first guide roller 24 and the first sprocket 26 are each rotatably mounted onto the baseplate 22 and may be rotated in either a clockwise or counterclockwise direction in FIGURE 1 about respective first 30 and second 32 rotation axes. The pivot arm 20 includes cutout portions 38 around the end flanges 28 of the first guide roller 24 and the first sprocket 26 which provide clearance to enable rotation of the first guide roller 24 and the first sprocket 26. In a preferred embodiment, the first 30 and second 32 rotation axes are coplanar. A main roller 34 is rotatably mounted to the pivot arm 20 to the right of the first guide roller 24 and the first sprocket 26. The main roller 34 may be rotated in either a clockwise or counterclockwise direction in FIGURE 1 about a third rotation axis 36.

The pivot arm 20 further includes a bracket 40 having a keeper roller 42 rotatably mounted thereon and an elongated slot 44. The keeper roller 42 is positioned above and adjacent to the first sprocket 26 such that the keeper roller 42 contacts edges of the print film 18. The bracket 40 is releasably secured to the pivot arm 20 by a pair of fasteners 46. One fastener is positioned within the slot 44 to enable adjustment of the keeper roller 42 relative to the print film 18.

The sound negative 16 is positioned to the left of the print film 18 and directly contacts the print film 18. The sound negative 16 and the print film 18 enter the module 14 from a substantially vertical position. In the module 14, the sound negative 16 contacts a right side of the first guide roller 24, the first sprocket 26 and the drive sprocket 12. The print film 18 contacts a left side of the main roller 36 at a printing point 62. As previously described, the first sprocket 26 is positioned above and to the left of the first guide roller 24 and to the right of the drive sprocket 12. In addition, the main roller 34 is positioned to the right of the first guide roller 24 and the first sprocket 26. Consequently, the sound negative 16 and the print film 18 are directed leftward after passing over the first guide roller 24 and travel in a substantially straight path from the first guide roller 20, past the main roller 34 to the first sprocket 26. Upon exiting the module 14, the print film 18 and sound negative 16 are directed in a substantially leftward direction over the drive

sprocket 12. As such, the distance traveled by the sound negative 16 through the module 14 is less than that traveled by the print film 18. This causes the sound negative 16 to undesirably slip with respect to the print film 18 resulting in an out of focus image of the soundtrack being reproduced. As a result, an out of focus or blurred soundtrack is undesirably formed on the print film 18.

In order to substantially eliminate slipping, a loop 48 is formed in the sound negative 18 between the first sprocket 26 and the drive sprocket 12. The loop 48 is formed by skipping at least one sprocket hole in the sound negative 16 and aligning the remaining sprocket holes with the sprocket holes in the print film 18. The teeth 82 of the first sprocket 26 are then inserted through the sprocket holes of both the sound negative 16 and the print film 18. The keeper roller 42 serves to provide pressure on the print film 18 and the sound negative 16 so as to maintain the teeth 82 of the first sprocket 26 within the sprocket holes and to thus form the loop 48. The module 14 further includes a fiber optic light source 56. The light source 56 includes a control knob 60 which enables an operator to turn on the light source 56 and vary the intensity of the light generated by the light source 56 as desired. Light from light source 56 is transmitted by a main cable 58 to a filter box 54. The filter box 54 enables the use of at least one light filter (not shown) to provide light suitable in color balance for exposing print film 18.

In addition, the filter box 54 includes a splitter (not shown) which serves to direct light to first 52 and second 53 fiber optic cables. The first 52 and second 53 cables extend from the filter box 54 to respective first 50 (not shown in FIGURE 1) and second 57 feed-through members. The first 50 and second 57 members are affixed by a bracket 51 to the baseplate 22 between the first sprocket 26 and the first guide roller 24. The first 50 and second 57 members include respective first 54 and second 55 light guides (only the second light guide 55 is shown) which are each positioned opposite the printing point 62. The first 52 and second 53 cables and the first 50 and second 57 members serve to transmit light from the filter box 54 to the first 54 and second 55 light guides, respectively. Light is then emitted from the first 54 and second 55 light guides which is utilized to transluminate the sound negative 16 and expose the print film 18 at printing

point 62 to form a portion of a digital soundtrack. An entire digital soundtrack is then formed on the print film 18 by utilizing the drive sprocket 12 to advance the entire sound negative 16 and the print film 18 upward past printing point 62. Furthermore, the module 14 includes first 66 and second 67 supply lines and an air supply 64. The first 66 and second 67 supply lines extend to the first 50 and second 57 members, respectively. The first 66 and second 67 supply lines and the first 50 and second 57 members serve to transport pressurized air from the air supply 64 to the first 54 and second 55 light guides, respectively. The pressurized air is then exhausted from the first 54 and second 55 light guides against the sound negative 16. This creates pressure against the sound negative 16, thus urging the sound negative 16 and the print film 18 against the main roller 34 at the printing point 62. This ensures that the sound negative 16 and the print film 18 are in contact at the printing point 62 so that a digital soundtrack may be accurately formed on the print film 18. It has been found that an air pressure of approximately 1 kilogram per square centimeter is suitable for maintaining contact.

Referring to FIGURE 2 in conjunction with FIGURE 1, a view of the module 14 along section line 2-2 of FIGURE 1 is shown. In FIGURE 2, the pivot arm 20 and main roller 34 are not shown for clarity. The print film 18 may be 35 millimeter film and have a standard configuration as specified in ANSI standard PH22.111, although other configurations may be used. The print film 18 and sound negative 16 each include a righthand column of sprocket holes 70 and a right edge 72 and a lefthand column of sprocket holes 74 and a left edge 76. In addition, a plurality of vertically arranged picture frames 78 are positioned between the lefthand 74 and righthand 70 columns of sprocket holes of the print film 18. An analog soundtrack (not shown), which may be a variable area soundtrack, is formed in a portion of the area between the righthand sprocket holes 70 and the picture frames 78 after the digital soundtrack 68 has been formed. As such, the configuration of the print film 18 conforms to generally accepted standards in the industry and is compatible with movie theaters having analog sound reproduction systems.

In a preferred embodiment, the first light guide 54 is positioned adjacent the right edge 72 and the second light guide 55 is positioned adjacent to the left edge 76. Light is then emitted from the first 54 and second 55 light guides for transluminating the sound negative 16 and to expose a section of the print film 18 at printing point 62. A digital soundtrack 68 is then formed on the print film 18 by driving the drive sprocket 12 to advance the entire sound negative 16 and the print film 18 past printing point 62. In FIGURE 2, the sound negative 16 and print film 18 are advanced upwardly past printing point 62 by the drive sprocket 12. As such, the digital soundtrack 68 is formed above printing point 62 (digital soundtrack 68 is not shown in area of first sprocket 26 and the first light guide 54 for clarity).

The digital soundtrack 68 is formed in sublayers of the print film 18 and is formed in an area between each of the righthand 70 sprocket holes. The digital soundtrack 68 is also formed in an area between each of the lefthand 74 sprocket holes. In addition, the digital soundtrack 68 extends from the right edge 72 to the righthand sprocket holes 70 and the left edge 76 to the lefthand sprocket holes 74. It is understood that other configurations for the digital soundtrack 78 may be obtained by changing the placement of the first 52 and second 53 cables.

Air exhausted from the first 54 and second 55 light guides creates pressure against the right 72 and left 76 edges, respectively, of the sound negative 16. This urges the right 72 and left edges 76 of the sound negative 16 and the print film 18 against the main roller 34 at the printing point 62. This ensures that the right 72 and left 76 edges of the sound negative 16 and the print film 18 are in contact at the printing point 62 so that a digital soundtrack may be accurately formed on the print film 18.

Referring to FIGURE 3 in conjunction with FIGURE 2, a cross sectional view of the first member 50 along section line 3-3 is shown. It is noted that the second member 57 has a similar configuration as the first member 50 and that the following description is exemplary of both the first 50 and second 57 members. The first member 50 includes an inlet end 88 and the first light guide 54 which includes an output end 90. A central opening 92 extends through first light guide 54 to the output end 90. A first passageway 94 extends through the first member

50 from the inlet end 88 to the central opening 92 and is in light communication with the central opening 92. Referring to FIGURE 1 in conjunction with FIGURE 3, this enables light transmitted from the first cable 52 to enter the first passageway 94 from the inlet end 88 and to travel through the first passageway 94 and the central opening 92. light is then emitted from the central opening 92 which serves to ultimately expose the print film 18 as previously described. In a preferred embodiment, the central opening 92 includes a reflecting element 96 such as aluminum foil which serves to harmonize light output.

Referring back to FIGURE 3, the first light guide 54 further includes an air channel 98 which extends circumferentially around the first light guide 54. A plurality of orifices 100 extend from the air channel 98 to the output end 90. The first member 50 further includes a second passageway 102 which extends from the inlet end 88 to the air channel 98 and is in fluid communication with the air channel 98 and thus the orifices 100. Referring to FIGURE 1 in conjunction with FIGURE 3, this enables pressurized air provided by the first supply line 66 to enter the second passageway 102 from the inlet end 88 and to travel through the second passageway 102, the air channel 98 and each of the orifices 100. Air is then exhausted from each of the orifices 100 which serves to provide pressure on the sound negative 16 to thus maintain contact between the sound negative 16 and the print film 18 as previously described.

In addition, the first member 50 includes flanges each having an elongated slot. The first member 50 is releasably secured to the bracket 51 by a fastener which extends through each slot. This enables adjustment of the position of the first member 50 relative to the right edge 72 (FIGURE 2) of the sound negative 16 and the print film 18 and the second member 57 as desired. It is noted that the second member 57 may also include slots to enable adjustment.

Referring to FIGURE 4, a view of the first light guide 54 along line 4-4 is shown. The central opening 92 may have a rectangular shape, although other shapes may be utilized. In addition, the orifices 100 may be arranged circumferentially around the central opening 92, although other configurations may be utilized. During normal operation of the printer, dust and other contaminants frequently form and collect within the central opening 92 of first

light guide 54. This undesirably blocks portions of light emitted through central opening 92 and substantially hinders the formation of portions of the digital soundtrack 68. Referring to FIGURE 5, an alternate embodiment of the first light guide 54 is shown. In this embodiment, the orifices 100 previously described are not included and the central opening 92 is enlarged to enable both light and air to be emitted from the first light guide 54. This enables dust and other contaminants which form within the central opening 92 to be continuously cleaned by the pressurized air stream emitted through the central opening 92. As such, the formation of the digital soundtrack 68 on the print film 18 is not substantially affected by dust and contaminant formation. It is noted that in this embodiment, the first 66 and second 67 supply lines extend directly to the first passageway 94 (FIGURE 3). Furthermore, to enable both light and air to be emitted from the central opening 92, the central opening 92 may be enlarged to any suitable size. One such size is approximately 2 millimeters wide and 4 millimeters long. Referring back to FIGURE 2, the first guide roller 24 and the first sprocket 26 are connected to the baseplate 22 by studs 104 having external stud threads 108. The end flanges 28 are positioned on opposite ends of the first guide roller 24 and first sprocket 26 and are spaced apart to accomodate the sound negative 16 and the print film 18. The end flanges 28 serve to guide the sound negative 16 and the print film 18 as they are advanced through the module 14. Hole registration of the print film 18 and the sound negative 16 is maintained by existing printer sprockets. In addition, the keeper roller 42 rolls on the right 72 and left 76 edges of the print film 18 so that teeth 82 of the first sprocket 26 remain inserted into righthand 70 and lefthand 74 sprocket holes of the sound negative 16 and print film 18 in order to form the loop 48.

As previously described, it is desirable that the sound negative 16 contacts the print film 18 at printing point 62 so that an accurate digital soundtrack is formed. However, during normal operation of the printer, the sound negative 16 or print film 18 may undesirably twist, thus causing the sound negative 16 to become separated from the print film 18. In a preferred embodiment, the position of the first guide roller 24 is adjustable in the left and right directions as shown by the arrow in FIGURE 2. This enables the end flanges 28 of the first

guide roller 24 to be adjustable in the left and right directions relative to the end flanges 28 of the first sprocket 26. As such, any undesirable twisting of the sound negative 16 or the print film 18 may be substantially eliminated by adjusting the position of first guide roller 24 to the left or right as required to ensure contact between the sound negative 16 and the print film 18 at printing point 62.

Referring to FIGURE 6 in conjunction with FIGURE 2, a view of the first guide roller 24 along line 6-6 is shown. In FIGURE 6, only a cross section of a stationary central portion 80 of the first guide roller 24 is shown. The first guide roller 24 includes internal threads 106 which are threadably engaged with the external stud threads 108. The stud 104 extends partially within the first guide roller 24 and includes a stud contact surface 110. The first guide roller 24 further includes a screw element 112 having external screw threads 114 which are also threadably engaged with the internal threads 106. The screw element 112 includes a screw contact surface 116 which is spaced apart from the stud contact surface 110. As such, the first guide roller 24 is moveable in the left and right directions relative to the stud 104 as indicated by the arrow by turning the central portion 80 of the first guide roller 24 relative to the stud 104. This enables the end flanges 28 of the first guide roller 24 to be adjustable in the left and right directions relative to the end flanges 28 of the first sprocket 26 in order to substantially eliminate twisting of the sound negative 16 and the print film 18.

In order to lock the first guide roller 24 in a desired position on the stud

104, the screw element 112 is advanced toward the stud 104 such that the screw contact surface 116 mates against the stud contact surface 110. This causes the screw element 112 to be pushed against the stud 104, resulting in an increase in friction between the internal threads 106 and the external screw 114 and stud 108 threads. This locks the first guide roller 24 in a desired position. Referring to FIGURE 7, the first guide roller 24 is shown locked in a desired position.

In order to move the first guide roller 24 to another position, the screw element 112 is moved away from the stud 104, thus reducing friction between the internal threads 106 and the external screw 114 and stud 108 threads. This unlocks the first guide roller 24 and enables the first guide roller 24 to be moved relative to the stud 104.

Referring back to FIGURE 1, the baseplate 22 further includes a stop block 84 having an adjustment screw 86 which is moveable into or out of the block 84. The pivot arm 20 is rotatable in clockwise and counterclockwise directions relative to the baseplate 22. The adjustment screw 86 serves to stop clockwise rotation of the pivot arm 20. In a first or closed position, the pivot arm 20 is rotated clockwise until the pivot arm 20 contacts the screw 86 and the main roller 34 contacts the print film 18 to form printing point 62. The position of the pivot arm 20 may be adjusted by moving the adjustment screw 86 into or out of the block 84 as desired in order to maintain contact between print film 18 and the sound negative 16 at printing point 62.

The module 10 further includes a locking mechanism 118 having a spring loaded locking pin 120 and a roller element 122. The roller element 122 is positioned underneath a portion of the first guide roller 24 and the pivot arm 20 and is rotatably affixed to the baseplate 22. As will be described, the locking mechanism 118 serves to maintain the pivot arm 20 in the closed position.

The pivot arm 20 and the main roller 34 may be rotated in a counterclockwise direction away from the adjustment screw 86 into a second or open position and then rotated clockwise back to the closed position as desired. Referring to FIGURE 8, the module 14 is shown in the open position. The open position enables the operator to thread the sound negative 16 and print film 18 through the module 14. In use, the operator positions the sound negative 16 on a right side of the first guide roller 24 and the first sprocket 26 and to the left of the print film 18. The operator then rotates the pivot arm 20 in a clockwise rotation until the pivot arm 20 contacts the adjustment screw 86, thus locating the pivot arm 20 in the closed position. This causes the print film 18 to contact the main roller 34 and the sound negative 16 such that the sound negative 16 is positioned a predetermined distance from the first 54 and second 55 light guides.

Referring to FIGURE 9, a cross sectional view of the pivot arm 20 and the pin 120 along section line 9-9 of FIGURE 8 is shown. The pivot arm 20 includes a cavity 124 having an open end 126 and a closed end 128. A collar 130 having a bore 132 and a collar end 134 is threadably affixed within the open end 126. The pin 120 includes an elongated portion 136 having a predetermined length and

a base portion 138 that is wider than the bore 132. The pin 120 is positioned such that the base portion 138 is located within the cavity 124 and the elongated portion 136 extends through the bore 132. The elongated portion 136 is vertically moveable within the bore 132. In an extended position, the base portion 138 contacts the collar 130. Consequently, the elongated portion 136 is fully extended out of the bore 132 and past the collar end 134. A spring 140 is positioned between the base portion 138 and the closed end 128. The spring 140 serves to urge the base portion 138 against the collar 130 thereby placing the pin 120 in the extended position. In a retracted position, an upward force is applied to the elongated portion

136 such that the elongated portion 136 is retracted into the bore 132, thereby biasing the pin 120 to move to the extended position. Referring to FIG 10, the pin 120 is shown in the retracted position. In this position, the spring 140 is compressed, thereby urging the pin 120 to move downward to the extended position. Upon removal of the upward force, the pin 120 is caused to move to the extended position by the spring 140.

Referring to FIGURES 11, 12 and 13, the operation of the locking mechanism 118 is shown as the pivot arm 20 is rotated to the closed position (FIGURE 1). In FIGURES 11, 12 and 13, a portion of the pivot arm 20 is depicted and the baseplate 22 is not shown for clarity. In FIGURE 11, the pivot arm 20 is shown rotated clockwise from the open position (FIGURE 8) and with the pin 120 in the extended position (FIGURE 9) at the moment before the pin 120 makes contact with the roller element 122.

In FIGURE 12, the pivot arm 20 is shown further rotated in a clockwise direction toward the closed position wherein the pin 120 contacts the roller element 122. This exerts an upward force on the elongated portion 136 of the pin 120 thereby retracting the pin 120 into the cavity 124 (FIGURE 10) and biasing the pin 120 such that the pin 120 is urged against the roller element 122. This causes the roller element 122 to rotate in a counterclockwise direction thus enabling the pivot arm 20 to rotate in the clockwise direction. The pivot arm 20 then rotates clockwise past the roller element 122 until the pivot arm 20 abuts

against the adjustment screw 86, thus placing the pivot arm 20 in the closed position (FIGURE 1).

Referring to FIGURE 13, the pivot arm 20 is shown in the closed position. After the pin 120 moves past the roller element 122, the spring 140 urges the pin 120 back into the extended position (FIGURE 9). Consequently, the pin 120 is positioned on a left side of the roller element 122. As such, contact between the elongated portion 136 of the pin 122 and the left side of the roller element 122 inhibits counterclockwise rotation of the pivot arm 20. In order to move the pivot arm 20 to the open position, a force is exerted in a counterclockwise clockwise direction on the pivot arm 20 sufficient to overcome the spring 140 bias on the pin 120. This retracts the pin 120 and enables the pivot arm 20 to be moved counterclockwise to the open position in a manner opposite from that described above. Upon rotating past the roller element 122, the pin 120 returns to the extended position (FIGURE 9). Referring to FIGURE 14, the module 14 is shown affixed to the top portion 10 of a Bell and Howell Model C Printer 142. In FIGURE 14, balloon section 144 is depicted as an enlarged view in FIGURE 15 for clarity. In an alternate embodiment, it is noted that the first guide roller 24, first sprocket 26, pivot arm 20, bracket 51 and locking mechanism 118 are directly attached to a contact printer. Referring to FIGURE 14 in conjunction with FIGURE 15, the light source 56 is affixed to a lower portion of the printer 142 and is coupled to a power supply (not shown). In accordance with the present invention, the operation of the printer 142 and the contact printing process are not substantially changed by the addition of the module 14. Printer 142 includes a first supply reel 146 for supplying the sound negative

16 and a first motorized take-up reel 148 for collecting the sound negative 16. The printer 142 further includes a second supply reel 150 for supplying the print film 18 and a second motorized take up-reel 152 for collecting the print film 18. In addition, the printer 142 includes a third supply reel 154 for supplying a picture negative 156 and a third motorized take-up reel 158 for collecting the picture negative 156. Furthermore, the printer 142 includes drive sprockets which coact with the lefthand 74 and righthand 70 sprocket holes (FIGURE 2) to advance the

15 sound negative 16, print film 18 and picture negative 156 from the supply reels 146, 150, 154 to the take up reels 148, 152, 158, respectively. In FIGURES 14 and 15, the direction of travel of the sound negative 16, print film 18 and picture negative 156 is indicated by arrows. The print film 18 and picture negative 156 are advanced from the second

150 and third 154 supply reels to a first set rollers which place the print film 18 and picture negative 156 in contact with each other. The first set of rollers guide the print film 18 and the picture negative 156 to a picture head 160. The picture head 160 serves to expose the print film 18 to form a positive print from the picture negative 156. The picture negative 156 is then separated from the print film 18 by a second set of rollers and collected by the third take-up reel 158.

The sound negative 16 and print film 18 are advanced to a third set of rollers which place the sound negative 16 and print film 18 in contact with each other. The sound negative 16 and the print film 18 are then advanced through the module 14 as previously described. The print film 18 is then exposed by light generated by the light source 56 and emitted by the first 54 and second 55 light guides (FIGURE 2) to form a positive print from the digital soundtrack on the sound negative 16. The sound negative 16 and print film 18 are then advanced through a fourth set of rollers to an analog sound head 160. The analog sound head 160 serves to expose the print film 18 to form a positive print from the analog soundtrack on the sound negative 16. The sound negative 16 is then separated from the print film 18 by a fourth set of rollers and is collected by the first take-up reel 148. Similarly, the print film 18 is advanced through a fifth set of rollers and is collected by the second take-up reel 152. As such, the module 14 is positioned before the analog sound head 160 in the sound negative 16 film path and after the picture head 160 in the print film 18 film path.

It is understood that many variations of the present invention are possible. For example, the present invention may be used to form a positive digital optical soundtrack directly onto the print film 18 without using a sound negative. Although the present invention is described in terms of a negative photographic process, an analogous positive process could also be used. Furthermore, in an alternate embodiment, the configuration of the first guide roller 24, first sprocket

26 and the main roller 34 are reversed. In this embodiment, the first guide roller 24 and first sprocket 26 are rotatably mounted to the pivot arm 20 and the main roller 34 is rotatably mounted to the baseplate 22.

Thus it is apparent that in accordance with the present invention, a module that fully satisfies the objectives, aims and advantages is set forth above. While the invention has been described in conjunction with specific embodiments, it is evident that many alternatives, modifications, permutations and variations will become apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended that the present invention embrace all such alternatives, modifications and variations as fall within the scope of the appended claims.