Electromagnetic digitizer and distortion-free LCD

• US 6,906,694 B2
• Filed: 07/19/2002
• Issued: 06/14/2005
• Est. Priority Date: 07/24/2001
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Namura, Takashi, Chikami, Toshihide, Iwamoto, Naohisa, Yamamoto, Sadao
• Primary Examiner(s): Shankar, Vijay
• Application Number:
  US10/198,043
• Publication Number:
  US 20030025677A1
• Time in Patent Office: 1,061 Days
• Field of Search: 345/87, 345 90- 92, 345/96, 345/104, 345/173, 345/175, 345/178, 345/179, 178 1801- 1807, 178 1901- 1904, 349/141, 349/143
• US Class Current: 345/104
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

An input/output device is disclosed that includes a digitizer with an LCD mounted thereon and a protective layer mounted directly on the LCD to minimize the parallax errors that have heretofore occurred when a protective layer was mounted in a spaced relation from an LCD. The LCD is a fringe field switching (FFS) LCD which does not distort when pressure is applied to its upper surface through the directly connected protective layer.

Claims

1. A device comprising:

a fringe field switching LCD including a top layer and a bottom layer;

a protective panel having a top face comprising a writing surface and a bottom face in contact with said to layer;

a stylus; and

a position detector operably connected to said LCD for detecting a position of said stylus on said writing surface and creating an image on said LCD at a location corresponding to said position.

2. The device of claim 1 wherein said position detector comprises a digitizer.

3. The device of claim 2 wherein said digitizer comprises an electromagnetic digitizer.

4. The device of claim 1 wherein said protective panel comprises a layer of acrylic.

5. The device of claim 1 wherein said protective panel comprises a layer of polycarbonate.

6. The device of claim 1 wherein said ton layer is a polarizer.

7. A device comprising:

a fringe field switching LCD having a top surface;

a flexible sheet of material having top face comprising a writing surface and a bottom face mounted over said ton surface of the LCD and spaced therefrom by a first distance, said sheet of material having a deflection distance greater than said first distance so that the bottom face is deflectably contactable with the top surface; and

a position detector operably connected to said LCD for detecting a position of a stylus on said writing surface and creating an image on said LCD at a location corresponding to said position.

8. A method of manufacturing a device comprising the steps of:

providing a fringe field switching LCD having a top surface;

attaching a protective layer of material having a top face comprising a writing surface and bottom face directly to said LCD top surface so that the bottom face is in contact with the toy surface;

operably connecting a position detector to said LCD for detecting a position of a stylus on said writing surface and creating an image on said LCD corresponding to said position.

9. An input/output device comprising:

a digitizer;

a fringe field switching LCD having a first side connected to said digitizer and a second side; and

a protective layer of material having a top face comprising a writing surface and a bottom face in face-to-face engagement with said LCD second side.

10. The input output device of claim 9 wherein said protective layer comprises a layer of acrylic.

11. The input output device of claim 9 wherein said protective layer comprises a layer of polycarbonate.

12. The input/output device of claim 9 wherein said LCD second side comprises a polarizer.

13. The input/output device of claim 9 wherein said digitizer comprises an electromagnetic digitizer.

14. The input/output device of claim 9 wherein said protective layer is removably attached to said LCD second side.

15. An input/output device comprising:

a digitizer having a toy surface; and

a fringe field switching LCD having a bottom layer in contact with said top surface and having a top layer, wherein said top layer comprises a writing surface for a digitizer stylus.

16. The input/output device of claim 15 wherein said LCD includes a polarization filter and wherein said top layer comprises said polarization filter.

17. The input/output device of claim 15 wherein said digitizer comprises an electromagnetic digitizer.

18. An input/output device comprising:

an electromagnetic digitizer having a top surface;

a fringe field switching LCD mounted on said digitizer; and

a protective layer of material removably mounted over said LCD, said protective layer selected from the group consisting of acrylic and polycarbonate, and said protective layer having a top face forming a writing surface and a bottom face spaced from said LCD by a gap having a width;

wherein said protective layer is resiliently deflectable by a deflection distance greater than the width of said gap when pressure is applied to said protective layer so that said bottom face is deflectably contactable with said LCD.

19. A method of manufacturing an input/output device comprising the steps of:

providing a digitizer;

mounting a fringe field switching LCD on said digitizer, the LCD having a top surface;

attaching a protective layer of material directly to the top surface of said LCD;

connecting said digitizer to said LCD such that a stylus having a tip moving across said protective layer will be detected by said digitizer and such that an image will be formed on said LCD beneath said stylus tip.

20. The input/output device of claim 19 wherein the step of providing a digitizer comprises the step of providing an electromagnetic digitizer.