Method and apparatus for converting film to line synchronized video signal data

• US 4,855,836 A
• Filed: 10/15/1987
• Issued: 08/08/1989
• Est. Priority Date: 10/15/1987
• Status: Expired due to Fees

• Current Assignee: Producers Color Service, Inc.
• Original Assignee: Producers Color Service, Inc.
• Inventors: Shearer, Thomas E.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Bauer, Robert M.
• Application Number:
  US07/108,559
• Time in Patent Office: 663 Days
• Field of Search: 358/214, 358/215, 358/216, 358/54
• US Class Current: 348/97
• CPC Class Codes: H04N 3/38 with continuously moving film

Abstract

Apparatus and method for converting information recorded on film to video signal data in which the film is transported in the direction of its length between light source and scanner optics in which each film frame is scanned by lines and scan data is stored in a frame buffer. The storage operation is synchronized by frame through an electro-optical assembly which is positioned to detect passage of film sprocket apertures toward the scanning station, which apertures possess a predefined relationship to the frame edges in accordance with industry standards. A shift register delay is responsive to pulses from a film transport tachometer for selectively delaying the synchronization signal to the buffer, and thereby accommodating both separation of the synchronization optics from the scanning station and variations in film transport velocity. The frame buffer is clocked to store data by scan line through a second tachometer, which thus likewise automatically compensates for variations in film transport speed.

Claims

1. Apparatus for converting to video signal data information recorded in frames on a film strip that includes a series of apertures at predetermined positions lengthwise of the film strip physically synchronized with onset of information frames recorded therein, said apparatus comprising a light source, scanner optics positioned in opposition to said light source for generating image data signals, means for directing said film strip lengthwise along a predetermined path between said light source and said scanner optics, means for receiving said image data signals, and means responsive to motion of the film strip for synchronizing said signal-receiving means to the onset of each said frame,

characterized in that said synchronizing means comprises electro-optical means positioned along said film path spaced from said scanner optics to direct light energy onto the film strip traveling in said path and responsive to passage of said apertures for producing a synchronizing signal indicating onset of an information frame between said light source and said scanner optics, means for directing said synchronizing signal to said receiving means to synchronize said receiving means, and means between said electro-optical means and said receiving means for delaying said synchronizing signal for a time corresponding to travel of the film strip from said electro-optical means to said scanner optics.

2. The apparatus set forth in claim 1 wherein said electro-optical means comprises a second light source for focusing light energy onto the film strip, guide means in said path for positioning the film strip with respect to said second light source such that the focused light energy is incident on said apertures, and means responsive to focused light energy reflected from said film strip for operating said synchronizing signals.

3. The apparatus set forth in claim 2 wherein said guide means comprises a guide roller adjacent to said second light source, and means positioned in said path for training the film strip over said guide roller between the surface thereof and said second light source, said surface being of optically nonreflective construction at least beneath apertures in said film strip illuminated by said second light source.

4. The apparatus set forth in claim 1 wherein said delaying means comprises means for generating motion signals as a function of motion of the film strip traveling in said path, and means for delaying said synchronizing signal as a function of said motion signals, such that timing of said synchronizing signal at said receiving means is automatically compensated for variations in film strip motion.

5. The apparatus set forth in claim 4 wherein said delay means includes means for adjusting said delay means as a function of film type.

6. The apparatus set forth in claim 1 wherein said signal-receiving means includes electronic memory means having a data input coupled to said scanner optics, a synchronizing input for receiving said synchronizing signal, and a clock input, and

wherein said apparatus further comprises means positioned in said film path and coupled to the film strip in said path for generating clock signals as a function of increments of travel of the film strip along said path, and means for directing said clock signals to said clock input such that storage of said image data signals in said memory means is automatically compensated for variations in film strip motion.

7. Apparatus for converting information recorded in frames on film to video signal data comprising a light source, scanner optics positioned in opposition to said light source for generating image data signals as a series of scan data lines, means for directing a film strip lengthwise along a predetermined path between said light source and said scanner optics in a direction normal to said scan data lines, synchronizing means responsive to motion of said film strip for generating synchronizing signals at onset of each said image frame between said light source and scanner optics, electronic memory means having a data input for receiving said image data signals by scan data lines, a synchronizing input for receiving said synchronizing signals and a clock input for clocking signals at said data input by scan line into said memory means, and means for generating clock signals to said clock input,

characterized in that said clock signal-generating means comprises means positioned in said film path and coupled to the film strip traveling in said path for generating said clock signals to said memory means as a function of increments of travel of the film strip along said path, such that storage of said data signals by scan data line in said memory means is automatically compensated for variations in film trip motion along said path.

8. The apparatus set forth in claim 7 wherein said synchronizing means comprises electro-optical means positioned to direct light energy onto said film strip for producing a synchronizing signal indicating onset of an information frame between said light source and said scanner optics, and means for directing said synchronizing signal to said synchronizing input of said memory means.

9. The apparatus set forth in claim 8 wherein the film strip includes a series of apertures at predetermined positions lengthwise of the film strip physically synchronized with onset of information frames recorded therein, and wherein said electro-optical means comprises means positioned to direct light energy onto the film strip traveling in said path and responsive to passage of said apertures for generating said synchronizing signals

10. In a method of converting image data stored in frames on film to video signals which includes the steps of (a) propelling the film lengthwise adjacent to image scanner means, (b) scanning each film frame in a plurality of scan lines from frame top to bottom to develop a series of scan line data, and (c) storing said scan line data in memory by line and frame, the improvement for automatically compensating storage of scan line data for variation in film speed comprising the step of (d) clocking storage of said scan line data as a function of film motion by (d1) sensing increments of lengthwise film motion and (d2) clocking said data as a function of said increments.

11. The method set forth in claim 10 comprising the additional steps of (e) sensing onset of each said image frame at said scanner means, and (f) synchronizing said storage of scan line data to onset of each said image frame.

12. Apparatus for converting to video signal data information recorded in frames on a film strip that includes a series of apertures at predetermined positions lengthwise of the film strip physically synchronized with onset of information frames recorded therein, said apparatus comprising a first light source, scanner optics positioned in opposition to said light source for generating image data signals, means for directing a film strip lengthwise along a predetermined path between said first light source and said scanner optics, means for receiving said image data signals, and means responsive to motion of said film strip for synchronizing said signal-receiving means to onset of each said frame,

characterized in that said synchronizing means comprises a second light source for focusing light energy onto the film strip, a guide roller adjacent to said second light source, means positioned in said path for training the film strip over said guide roller between the surface thereof and said second light source such that the focused light energy is incident on the apertures in the film strip, said surface being of optically non-reflective construction at least beneath apertures in the film strip illuminated by said second light source, and means responsive to focused light energy reflected from said film strip for generating a synchronizing signal indicating onset of an information frame between said first light source and said scanner optics, and means for directing said synchronizing signal to said receiving means to synchronize said receiving means.

13. The apparatus set forth in claim 12 wherein said electro-optical means is positioned along said film path spaced from said scanner optics, and wherein said apparatus further comprises means between said electro-optical means and said receiving means for delaying said synchronizing signals for a time corresponding to travel of the film strip from said electro-optical means to said scanner optics.

14. In a method of converting image data stored in frames on film to video signals that includes the steps of (a) propelling the film lengthwise adjacent to image scanner means, (b) scanning each film frame in a plurality of scan lines from frame top to bottom to develop a series of scan line data, and (c) storing said scan line data in memory by line and frame, the improvement for automatically compensating storage of scan line data for variation in film speed comprising the steps of (d) clocking storage of said scan line data as a function of film motion, (e) sensing onset of each said image frame at said scanner means, and (f) synchronizing said storage of scan line data to onset of each said image frame.

15. The method set forth in claim 14 wherein said step (d) comprises the steps of (d1) sensing increments of lengthwise film motion and (d2) clocking said data as a function of sad increments.

16. The method set forth in claim 14 wherein said step (e) comprises the steps of (e1) sensing passage of each said image frame in the strip at a position spaced from said scanner means to develop a synchronizing signal, and (e2) delaying application of said synchronizing signal to said memory for a time duration which varies as a function of film strip velocity.