Handwriting capture system with segmented digitizer

• US 5,563,381 A
• Filed: 04/17/1995
• Issued: 10/08/1996
• Est. Priority Date: 06/21/1993
• Status: Expired due to Term

• Current Assignee: NCR Corporation
• Original Assignee: NCR Corporation
• Inventors: Protheroe, Robert L., Crooks, John F.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): LOOMIS, PAUL A
• Application Number:
  US08/400,733
• Time in Patent Office: 540 Days
• Field of Search: 178/18-20, 345/173, 345/174, 345/179, 345/156
• US Class Current: 178/18.03
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A handwriting capture system which includes a handwriting capture device containing a segmented digitizer. The handwriting capture device also includes circuitry which processes handwriting information entered into the segmented digitizer, a controller which determines position coordinates associated with the handwriting information, a memory coupled to the controller which stores position coordinates, and circuitry coupled between the controller and the segmented digitizer which drives and calibrates the segmented digitizer. The system also includes a host computer system coupled to the controller through an interface so that the controller can upload positional coordinates to the host system.

Claims

1. A digitizer input system comprising:

a segmented digitizer, including

a first layer having a plurality of groups of adjacent conductive strips, wherein the conductive strips are electrically isolated from each other and generally oriented in a first direction, and wherein each group of conductive strips is electrically isolated from any other group of conductive strips;

a second layer adjacent the first layer having a number of groups of adjacent conductive strips, wherein the conductive strips are electrically isolated from each other and generally oriented in a second direction different than the first direction, and wherein each group of conductive strips in the second layer is electrically isolated from any other group of conductive strips in the second layer; and

a spacer between the first and second layers;

circuitry which processes information entered into at least one of the segments of the segmented digitizer; and

a controller which determines position coordinates associated with the information.

2. A digitizer input system comprising:

a digitizer device including

a segmented digitizer including a plurality of segments formed from a first layer having a plurality of electrically isolated groups of adjacent conductive strips, a second layer having a number of electrically isolated groups of adjacent conductive strips, and a plurality of spacers between the first and second layer;

wherein the segmented digitizer further includes a drive electrode for each conductive strip of the first and second layers, and a sense electrode for at least one conductive strip of either the first and second layers;

wherein the conductive strips of each of the groups of the first layer are electrically isolated from each other and from any other group in the first layer and generally oriented in a first direction;

wherein the conductive strips of each of the groups of the second layer are electrically isolated from each other and from any other group in the second layer and generally oriented in a second direction substantially orthogonal to the first direction; and

wherein the number of segments is equal to the number of groups in the first layer multiplied by the number of groups in the second layer;

circuitry coupled to the sense electrodes which processes information entered into one or more segments of the segmented digitizer;

a controller which determines position coordinates associated with the information; and

circuitry coupled between the controller and the drive electrodes of the segmented digitizer which drives and calibrates the segmented digitizer including at least one electrical source, and a plurality of switches controlled by the controller for selectively coupling the source to predetermined drive electrodes;

a host computer system coupled to the controller so that the controller can upload positional coordinates to the host system; and

an interface between the controller and the host system.

3. A digitizer input device comprising:

a segmented digitizer, including

a first layer having a plurality of groups of adjacent conductive strips, wherein the conductive strips are electrically isolated from each other and generally oriented in a first direction, and wherein each group of conductive strips is electrically isolated from any other group of conductive strips;

a second layer adjacent the first layer having a number of groups of adjacent conductive strips, wherein the conductive strips are electrically isolated from each other and generally oriented in a second direction different than the first direction, and wherein each group of conductive strips in the second layer is electrically isolated from any other group of conductive strips in the second layer; and

a spacer between the first and second layers;

circuitry which processes information entered into at least one of the segments of the segmented digitizer; and

a controller which determines position coordinates associated with the information.

4. A segmented digitizer comprising:

a plurality of segments formed by the combination of a first layer having a plurality of electrically isolated groups of adjacent conductive strips, a second layer having a number of electrically isolated groups of adjacent conductive strips, and a plurality of spacers between the first and second layers;

wherein the conductive strips of each of the groups of the first layer are electrically isolated from each other and from any other group in the first layer and generally oriented in a first direction;

wherein the conductive strips of each of the groups of the second layer are electrically isolated from each other and from any other group in the second layer and generally oriented in a second direction substantially orthogonal to the first direction; and

wherein the number of segments is equal to the number of groups in the first layer multiplied by the number of groups in the second layer.

5. A digitizer input device comprising:

a segmented digitizer including a plurality of segments formed from the combination of a first layer having a plurality of electrically isolated groups of adjacent conductive strips, a second layer having a number of electrically isolated groups of adjacent conductive strips, and a plurality of spacers between the first and second layers;

wherein the segmented digitizer further includes a drive electrode for each conductive strip of the first and second layers, and a sense electrode for at least one conductive strip of either the first and second layers;

wherein the conductive strips of each of the groups of the first layer are electrically isolated from each other and from any other group in the first layer and generally oriented in a first direction;

wherein the conductive strips of each of the groups of the second layer are electrically isolated from each other and from any other group in the second layer and generally oriented in a second direction substantially orthogonal to the first direction; and

wherein the number of segments is equal to the number of groups in the first layer multiplied by the number of groups in the second layer;

circuitry coupled to the sense electrodes which processes information entered into one or more segments of the segmented digitizer;

a controller which determines position coordinates associated with the information; and

circuitry coupled between the controller and the drive electrodes of the segmented digitizer which drives and calibrates the segmented digitizer including at least one electrical source, and a plurality of switches controlled by the controller for selectively coupling the source to predetermined drive electrodes.

6. A segmented digitizer comprising:

a first layer including a plurality of electrically isolated groups of adjacent conductive strips generally oriented in a first direction; and

a second layer adjacent the first layer including a number of electrically isolated groups of adjacent conductive strips generally oriented in a second direction substantially orthogonal to the first direction;

wherein the first and second layers combine to form a number of segments equal to the number of groups in the first layer multiplied by the number of groups in the second layer.