Video imaging device in a teleconferencing system

• US 5,038,224 A
• Filed: 12/22/1989
• Issued: 08/06/1991
• Est. Priority Date: 12/22/1989
• Status: Expired due to Term

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Bell Communications Research, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Martulli, Donald L., Smoot, Lanny S.
• Primary Examiner(s): Coles, Sr., Edward L.
• Assistant Examiner(s): Grant, II, Jerome
• Application Number:
  US07/455,309
• Time in Patent Office: 592 Days
• Field of Search: 358/401, 358/408, 358/446, 358/447, 358/448, 358/450, 358/452, 358/475, 358/487, 358/488, 358/494, 358/497, 358/400, 250/201.1, 250/201.9, 250/229, 250/205, 355/71, 355/83, 350/339, 350/330
• US Class Current: 358/446
• CPC Class Codes: H04N 1/00795 Reading arrangements details of scanning heads H04N1/024; scanning arrangements therefor H04N1/04
• CPC Class Codes: H04N 1/00822 Selecting or setting a particular reading mode, e.g. from amongst a plurality of modes, simplex or duplex, or high or low resolution
• CPC Class Codes: H04N 1/04 Scanning arrangements , i.e. arrangements for the displacement of active reading or reproducing elements relative to the original or reproducing medium, or vice versaH04N1/387 takes precedence
• CPC Class Codes: H04N 1/195 the array comprising a two-dimensional array or a combination of two-dimensional arrays
• CPC Class Codes: H04N 1/19584 Combination of arrays
• CPC Class Codes: H04N 1/19594 using a television camera or a still video camera
• CPC Class Codes: H04N 1/40056 Circuits for driving or energising particular reading heads or original illumination means H04N1/401, H04N1/407 take precedence
• CPC Class Codes: H04N 2201/0418 capable of scanning transmissive and reflective originals at a single scanning station
• CPC Class Codes: H04N 7/144 camera and display on the same optical axis, e.g. optically multiplexing the camera and display for eye to eye contact

Abstract

A video imaging device permits a first teleconference participant to transport information contained on copy material to a second teleconference participant for display in a portion of a video image viewed by the second teleconference participant. The video imaging device automatically reconfigures itself to transmit information contained on transparent, translucent, or opaque copy material.

Claims

1. A video imaging device for transmitting a video image of copy material comprising

a sheet which can be switched between a translucent and a transparent state,

a video camera for viewing said copy material through said sheet,

an optical sensor for sensing the amount of ambient light transmitted through said sheet, said amount of ambient light depending on whether said copy material is transparent or translucent, and

a control circuit for causing said sheet to be transparent when said copy material is translucent and for causing said sheet to be translucent when said copy material is transparent.

2. The video imaging device of claim 1 wherein said video imaging device includes an internal source of lighting, wherein said control circuit activates said internal source of lighting and causes said sheet to be transparent when said copy material is opaque.

3. The video imaging device of claim 1 wherein said device include means for holding said copy material in contact with said sheet.

4. The video imaging device of claim 1 wherein said device is contained in an enclosure, wherein said enclosure includes a source of vacuum for holding copy material in close contact with said sheet, and wherein said device includes a vacuum sensor for producing an output signal indicative of the presence of copy material.

5. The video device of claim 1 wherein said sheet comprises a liquid crystal material.

6. The video imaging device of claim 1 wherein said video imaging device includes means for generating an electrostatic holding force on said copy material and sensor means for providing an output signal indicative of the presence of copy material.

7. The video imaging device of claim 1 wherein said device includes sensor means for providing a signal indicative of the presence of copy material.

8. The video imaging device of claim 7 wherein said signal activates a picture-in-picture device associated with a teleconferencing system so that said copy material may be viewed in a video display.

9. The device of claim 1 wherein said video imaging device includes a video projector for projecting a video image onto a rear surface of said sheet when copy material is not present.

10. A video imaging device for use in a teleconferencing system for transmitting a video image of transparent or translucent copy material, said video imaging device comprising,

a liquid crystal sheet which can be switched between a translucent and a transparent state,

sensor means for providing an output signal indicative of the presence of copy material,

a video camera which can view said copy material through said liquid crystal sheet,

an optical sensor for sensing the amount of ambient light transmitted through said sheet, the amount of ambient light depending on whether said copy material is transparent or translucent, and

control means responsive to said optical sensor for causing said liquid crystal surface to be transparent when said copy material is translucent and for causing said liquid crystal surface to be translucent when said copy material is transparent.

11. The video imaging device of claim 10 wherein said output signal activates a picture-in-picture device for combining a first video signal produced by said camera with a second video signal to produce a composite video image at a teleconferencing station.

12. The video imaging device of claim 10 wherein said copy material is transparent, translucent or opaque, wherein said device includes an internal light source and wherein said control circuit causes said liquid crystal sheet to be transparent and activates said internal light source when said copy material is opaque.