Flat panel display with integrated digitizing tablet

• US 4,873,398 A
• Filed: 06/30/1988
• Issued: 10/10/1989
• Est. Priority Date: 06/30/1988
• Status: Expired due to Term

• Current Assignee: HP Inc.
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Hubby, Laurence M. Jr.
• Primary Examiner(s): SCHREYER, STAFFORD
• Application Number:
  US07/213,756
• Time in Patent Office: 467 Days
• Field of Search: 178/18, 178/19, 350/117, 350/121, 350/122, 340/705, 340/706, 340/784
• US Class Current: 178/18.07
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment

Abstract

A novel flat panel display is provided which allows for very precise and reliable detection of the location of the cursor with respect to the displayed image. Parallax problems are eliminated by focusing the displayed image on a panel by projecting the image through the panel. The location of the stylus is accurately determined, in one embodiment, utilizing prior art digitizing techniques together with the use of an erect, unity magnification imaging lens array for displaying the projected image. In another embodiment of this invention, accurate determination of the location of the stylus with respect to the displayed image is provided by causing the stylus to feed signals, for example optical signals, through a significant portion of the optical path used for displaying the image.

Claims

1. A flat panel display comprising:

a screen;

means for projecting an image; and

a substantially thin lens for focusing said image on said screen.

2. A flat panel display as in claim 1 wherein said lens comprises an erect unity magnification imaging lens array.

3. A flat panel display as in claim 1 further comprising means for determining the position of a stylus when said stylus is placed adjacent to said screen.

4. A flat panel display as in claim 3 wherein said means for determining comprises a digitizer.

5. A flat panel display as in claim 4 wherein said digitizer is either an electrostatic or an electromagnetic digitizer.

6. A flat panel display as in claim 3 wherein said means for determining comprises an imaging device which receives a position signal from said stylus.

7. A flat panel display as in claim 6 wherein said position signal is transmitted to said imaging device through said erect unity magnification imaging lens array.

10. A display as in claim 7 or 9 wherein said position signal is distinguishable from said image by wavelength, modulation, or polarization.

11. A display as in claim 10 further comprising means for separating said position signal from said image.

12. A display as in claim 11 wherein said means for separating comprises a beamsplitter.

8. A display comprising:

a screen;

means for projecting an image;

means for focusing said image on said screen;

means for determining the position of a stylus when said stylus emits a position signal when placed adjacent to said screen, said means for determining comprising an image device for receiving said position signal.

9. A display as in claim 8 wherein said image device receives said position signal through said means for focusing.

13. An interactive computer terminal comprising:

a translucent work surface having a front and back;

means for projecting an image from the back of the work surface to the front of the work surface so as to focus the image on the front of the work surface;

indicator means producing a signal for use on the front of the work surface by an operator; and

means for receiving the signal produced by the indicator means.

14. An interactive computer terminal for outputting information to an operator and inputting information from the operator, comprising:

a translucent work surface having a front and back;

means for projecting an image, containing the information to be outputted, from the back of the work surface to the front of the work surface so as to focus the image on the front of the work surface to be viewed by the operator;

indicator means producing a signal for use on the front of the work surface by an operator so as to indicate information to be inputted; and

means for receiving the signal produced by the indicator means so as to produce the information to be inputted.