Video hard copy controller

• US 4,165,520 A
• Filed: 10/17/1977
• Issued: 08/21/1979
• Est. Priority Date: 10/17/1977
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Wessler, Louis E., Koch, Kenneth F., Cleveland, Andrew J.
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US05/842,992
• Time in Patent Office: 673 Days
• Field of Search: 358/127, 358/256, 358/280, 358/302, 358/141, 358/181, 358/903
• US Class Current: 358/409
• CPC Class Codes: G03G 15/32 in which the charge pattern is formed dotwise, e.g. by a thermal headG03G15/04, G03G15/05, G03G15/34 take precedence
• CPC Class Codes: H04N 1/3875 combined with enlarging or reducing enlarging or reducing per se H04N1/393

Abstract

A video hard copy controller includes first means for receiving serial input video signals from a first source. Second means is coupled to the first means for converting the serial input video signals into a first set of parallel digital signals. Third means is coupled to the second means for receiving the first set of parallel digital signals. The third means includes means for receiving a second set of parallel digital signals from a second source and means responsive to a control signal for selecting between the first and second sets of parallel digital signals for output to a hard copy generating device in order to produce a hard copy fascimile of the images represented by the selected set of parallel digital video signals.

Claims

1. A video hard copy controller comprising:

first means for receiving serial input video signals from a first source;

second means coupled to said first means for converting said serial input video signals into a first set of parallel digital signals; and

third means coupled to said second means for receiving said first set of parallel digital signals, said third means including means for receiving a second set of parallel digital signals from a second source and means responsive to a control signal for selecting between said first and second sets of parallel digital signals for output to a hard copy generating device in order to produce a hard copy fascimile of the images represented by the selected set of parallel digital signals.

2. The video hard copy controller of claim 1, wherein said serial input video signals are analog signals including a video data component and a synchronization component, and said second means comprises:

data detect means coupled to said first means for separating said video data component out of said serial input video signals and for then converting said video data component from analog to digital format; and

serial-parallel converter means coupled to said data detect means for converting said video data component now in digital format to said first set of parallel digital signals.

3. The video hard copy controller of claim 1, wherein said third means comprises a data select multiplexer having first inputs for receiving said first set of parallel digital signals, second inputs for receiving said second set of parallel digital signals, and a control input for receiving said control signal.

4. The video hard copy controller of claim 1, wherein said serial input video signals are in accordance with one or more standard EIA video formats.

5. The video hard copy controller of claim 1, wherein said first means comprises a video source multiplexer capable of receiving serial input video signals from any one or more of a plurality of video sources, said multiplexer including means responsive to a command signal for selecting the serial input video signals from one of said video sources.

6. The video hard copy controller of claim 5, wherein said first means further comprises video input circuits coupled to said multiplexer, said video input circuits including:

a video amplifier circuit to which said serial input video signals are coupled for amplifying said serial input video signals; and

an automatic gain control circuit coupled in feedback relation between the output of said video amplifier and an input thereof.

7. The video hard copy controller of claim 6, wherein said video input circuits further include a video d-c restorer circuit coupled to the output of said video amplifier circuit for maintaining the amplified video signals in a predetermined relationship with respect to a predetermined reference potential.

8. The video hard copy controller of claim 7, wherein said serial input video signals are analog signals including a video data component and a synchronization component, and said second means comprises:

data detect means coupled to said first means for separating said video data component out of said serial input video signals and for then converting said video data component from analog to digital format; and

serial-parallel converter means coupled to said data detect means for converting said video data component now in digital format to said first set of parallel digital signals.

9. The video hard copy controller of claim 8, wherein said third means comprises a data select multiplexer having first inputs for receiving said first set of parallel digital signals, second inputs for receiving said second set of parallel digital signals, and a control input for receiving said control signal.

10. The video hard copy controller of claim 9, wherein said serial input video signals are in accordance with one or more standard EIA video formats.

11. A video hard copy reproduction system comprising:

at least one input video source capable of generating serial video signals;

a digital source capable of generating a first set of parallel digital signals;

a video hard copy controller including first means for receiving said serial input video signals from said at least one input video source, second means coupled to said first means for converting said serial video signals into a second set of parallel digital signals, and third means coupled to said digital source for receiving said first set of parallel digital signals, said third means being responsive to a control signal for selecting between said first and second sets of parallel digital signals for output from said video hard copy controller; and

a hard copy generating device coupled to the output of said video hard copy controller for producing a hard copy fascimile of the images represented by the selected set of parallel digital signals.

12. The video hard copy reproduction system of claim 11, wherein said serial video video signals are in accordance with any one or more standard EIA video formats.

13. The video hard copy reproduction system of claim 11, wherein said digital source is a central processing unit.

14. The video hard copy reproduction system of claim 11, wherein said video hard copy controller further comprises means for selectively vertically expanding the hard copy facsimile formed by said hard copy generating device.

15. The video hard copy reproduction system of claim 11, wherein said video hard copy controller further comprises means for selectively horizontally expanding the hard copy facsimile formed by said hard copy generating device.

16. The video hard copy reproduction system of claim 11, wherein said video hard copy controller further comprises:

means for selectively vertically expanding the hard copy facsimile formed by said hard copy generating device; and

means for selectively horizontally expanding said hard copy facsimile.

17. The video hard copy reproduction system of claim 11, wherein said hard copy generating device is an electrostatic printer/plotter.

18. The video hard copy reproduction system of claim 17, wherein the selected set of parallel digital signals is transmitted one video line at a time to said printer/plotter which includes a plurality of electrostatic recording elements proportional in number to the total number of video bits supplied from the video hard copy controller for each video line.

19. The video hard copy reproduction system of claim 18, wherein said video hard copy controller further comprises fourth means for synchronizing the transmittal of the selected parallel digital signals representative of each video line with the print/plot speed of the printer/plotter.

20. The video hard copy reproduction system of claim 19, wherein said fourth means comprises video line pointer circuits which include:

first storage means for storing a count indicative of a desired video line to be transmitted to the printer/plotter;

second storage means for storing a count indicative of the current line of video of the selected set of parallel digital signals being received by said video hard copy controller; and

means for comparing the counts in said first and second storage means and for generating a predetermined command signal when said counts are equal.

21. The video hard copy reproduction system of claim 20, wherein said video hard copy controller further comprises fifth means responsive to said predetermined command signal for causing said selected set of parallel digital signals to be transmitted to said printer/plotter.

22. The video hard copy reproduction system of claim 11, further comprising at least one video monitor for displaying a video data component of said serial input video signals from said at least one input video source.

23. The video hard copy reproduction system of claim 22, wherein said serial video signals are in accordance with any one or more standard EIA video formats.

24. The video hard copy reproduction system of claim 23, wherein said digital source is a central processing unit.

25. The video hard copy reproduction system of claim 24, wherein said hard copy generating device is an electrostatic printer/plotter.

26. The video hard copy reproduction system of claim 25, further comprising remote control means for supplying various remote control signals to said video hard copy controller for remotely controlling same.

27. The video hard copy reproduction system of claim 26, further comprising a printer/plotter controller coupled between said central processing unit and said video hard copy controller for controlling the application of said first set of parallel digital signals to said video hard copy controller.