Pen input device for high resolution displays

• US 5,933,135 A
• Filed: 10/24/1996
• Issued: 08/03/1999
• Est. Priority Date: 10/24/1996
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Martin, Russel A.
• Primary Examiner(s): Hofsass, Jeffery A.
• Assistant Examiner(s): TWEEL JR, JOHN ALEXANDER
• Application Number:
  US08/738,952
• Time in Patent Office: 1,013 Days
• Field of Search: 345/179, 345/180, 345/157, 345/145, 345/160, 345/156, 345/181, 345/182, 345/183, 382/313, 382/314, 178/18
• US Class Current: 345/179
• CPC Class Codes: G06F 3/03542 Light pens for emitting or receiving light
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/04892 Arrangements for controlling cursor position based on codes indicative of cursor displacements from one discrete location to another, e.g. using cursor control keys associated to different directions or using the tab key arrangements for controlling cursor position based on coordinate signals G06F3/038

Abstract

A pen input system and method is disclosed for identifying a cursor location on a high resolution display. A pen includes a pointer for pointing to a desired point on a display screen for positioning of the cursor. A low resolution locator generally localizes the point to which the pen is pointing at a first location in a host processor, through a cursor control, and positions the cursor at the first location. The pen includes an imager for viewing an image of a portion of the screen including the cursor and the desired point to which the pen is pointing. The host processor can determine a variance between the desired point, which is the center point of the image viewed by the imager in the pen and the actual cursor location. This variance is determined by the processor which then repositions the cursor at the desired point.

Claims

1. A pen assembly for controlling a position of a cursor on a display device comprising:

a pen including a pointer for pointing to a desired point on a screen of the display device where the cursor is to be located;

a low resolution locator associated with the screen for identifying a first location indicated by the pen on the screen relative to the desired point;

a cursor controller for positioning the cursor on the screen at the first location;

an imager for directly viewing an image of a portion of the screen including the first location;

a host processor in signal communication with the pen, the low resolution locator and the imager, for detecting from the image a variance between the first location and the desired point and wherein the cursor controller in response to the detected variance repositions the cursor at a second location comprising the desired point.

2. The pen assembly as defined in claim 1 wherein the imager comprises a camera disposed in the pen in a general alignment for viewing the desired point and the cursor at the first location.

3. The pen assembly as defined in claim 1 wherein the detected variance comprises a spacing measured from the cursor at the first location to a central location of the image comprising the desired point.

4. The pen assembly as defined in claim 1 wherein the cursor comprises a nonsymmetrical configuration and the host processor comprises means for detecting a relative position and orientation of the cursor to the desired point.

5. A method for improved accuracy of control of a cursor of an high resolution display comprising the steps:

pointing a pen to a desired point on the display;

identifying a first location on the display with a low resolution position detection system wherein the first location is generally approximate the desired point;

displaying the cursor at the first location;

sensing an image of a portion of the display including the desired point and the cursor at the first location;

identifying a variance in position between the desired point and the cursor at the first location from the sensed image; and

,

moving the cursor to the desired point whereby the variance is essentially eliminated.

6. The method as claimed in claim 5 wherein the sensing comprises disposing a camera in the pen wherein the camera will be aimed at the desired point for viewing the image and the variance.

7. The method as claimed in claim 5 wherein the displaying the cursor comprises displaying a nonsymmetrical pattern.

8. The method as claimed in claim 5 wherein the identifying the variance comprises measuring a spacing between the first location and the desired point exclusive of pen tilt, rotation and location.

9. The method as claimed in claim 8 wherein the sensing comprises focusing the portion through an optics lens onto a charge coupled device functioning as the imager, and wherein a host processor computes the spacing and signals a cursor controller for the moving of the cursor to a second location comprising the desired point.

10. The method as defined in claim 5 wherein said moving continually corresponds to said point as the pen is additionally moved for point to a different desired point.

11. A pen input system for identifying a cursor location on a high resolution active matrix liquid crystal display associated with a host processor comprising:

a pen including a pointer for pointing to a desired point on a screen of the display at where the cursor is desired to be located;

a low resolution tablet disposed to overlay the screen and calibrated to the screen for identifying a first location on the screen at which the cursor is to be located in response to an input from the pen on the tablet;

a host processor in signal communication with the pen, the tablet and the display for disposing the cursor at the first location in response to a first locating signal from the pen and tablet; and

,

an imager in association with the pen for generating an image recognizable by the host processor to comprise a portion of the display including the desired point and the first location wherein the host processor identifies a variance between the first location and the desired point from the image and moves the cursor to a second location comprising the desired point.

12. The pen input system as claimed in claim 11 wherein the imager comprises a camera and associated optics assembly disposed in the body of the pen.

13. The pen input system as defined in claim 11 wherein said imager has a resolution finer than said high resolution display.

14. The pen input system as defined in claim 11 wherein said pen comprises a plurality of pens and said cursor comprises a plurality of cursors.