Graphics surface assembly with calibrating memory device

• US 5,101,081 A
• Filed: 03/25/1991
• Issued: 03/31/1992
• Est. Priority Date: 03/25/1991
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: Wang Laboratories Incorporated
• Inventors: Drumm, Donald E.
• Primary Examiner(s): SCHREYER, STAFFORD
• Application Number:
  US07/675,250
• Time in Patent Office: 372 Days
• Field of Search: 178/18, 178/19
• US Class Current: 345/174
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads

Abstract

An electrographic system comprises a graphics surface assembly having a graphics surface integrally coupled to a memory device which contains calibration data designated for the graphics surface. During manufacturing, the memory device is mounted onto an interface board which is attached to the graphics surface through a flex cable. A calibration procedure is performed on the graphics surface whereby calibration data is generated and stored in the memory device. The memory device, loaded with the calibration data, is thereafter linked to its associated graphics surface.

Claims

1. In an electographic system in which a controller located on a main electronics board provides position indications for an element positioned relative to a graphics surface, a graphics surface assembly comprising:

a graphics surface having a conductive layer on an insulative support layer;

a first cable connected to the conductive layer of the graphics surface and having signal lines for communications between the conductive layer and the controller; and

a memory device coupled to the first cable and remotely located with respect to the main electronics board and having calibration data which the controller accesses to compensate for the conductive layer in providing position indications for the element.

2. A graphics surface assembly as claimed in claim 1 further comprising an interface board connected to the first cable, the interface board having signal lines for communications between the conductive layer and the controller, the interface board having the memory device mounted thereon, and the interface board having additional signal lines for communications between the memory device and the controller.

3. A graphics surface assembly as claimed in claim 2 further comprising a second cable connected to the interface board, the second cable having signal lines for communications with the controller.

4. A graphics surface assembly as claimed in claim 1 wherein the memory device is mounted on the first cable, the first cable having additional signal lines for communications between the memory device and the controller.

5. A graphics surface assembly as claimed in claim 1 wherein the memory device is a programmable read only memory device.

6. A graphics surface assembly as claimed in claim 1 wherein the insulative support layer comprises a transparent substrate.

7. A graphics surface assembly as claimed in claim 1 wherein the conductive layer has a non-uniform surface resistance.

8. A graphics surface assembly as claimed in claim 1 wherein the first cable comprises a flex cable having a printed circuit comprising a plurality of signal lines.

9. A graphics surface assembly as claimed in claim 1 wherein the element positioned adjacent to the graphics surface is a stylus.

10. In an electrographic system in which a controller located on a main electronics board provides a position indication for a member positioned adjacent to a graphics surface, a graphics surface assembly comprising:

a graphics surface having a unique resistive layer deposited on an transparent support substrate;

a flex cable attached to the resistive layer and having signal lines for communications with the resistive layer;

an interface board attached to the flex cable, the interface board having signal lines for communications with the flex cable and having additional signal lines printed thereon; and

a memory device mounted onto the interface board and connected to the additional signal lines of the interface board, the memory device being remotely located with respect to the controller, and the memory device having calibration data compiled during a calibration procedure for the graphics surface whereby the calibration data corresponds to the unique resistive layer.

11. In an electrographic system in which a member is positioned upon a graphics surface of a graphics tablet, the graphics surface having a unique conductive layer deposited on an insulative support structure, a cable being connected to the conductive layer for providing electrical signals between the conductive layer and a controller located on a remote main electronics board, the controller being coupled to a memory device also located on the remote main electronics board and having calibration data designated for the unique conductive layer, the controller accessing the calibration data of the memory device for compensating for the unique conductive layer in determining the position of the member relative to the graphics surface;

the improvement comprising;

a first cable attached to the conductive layer of the graphics surface, the first cable having signal lines for communications between the conductive layer and the controller; and

a memory device coupled to the first cable and having the calibration data for use by the controller in determining the position of the member, wherein the memory device is remotely located with respect to the main electronics board.

12. An electrographic system as claimed in claim 11 further comprising an interface board connected to the first cable and having the memory device mounted thereon and having signal lines for communications with the first cable and having additional signal lines for communications with the memory device.

13. An electrographic system as claimed in claim 12 further comprising a second cable connected to the interface board and having signal lines for communications with the controller.

14. An electrographic system as claimed in claim 11 in which the memory device is mounted onto the first cable, the first cable having additional signal lines for communications between the controller and the memory device.

15. In an electrographic system in which the position of a stylus placed upon a graphics surface is determined by a controller remotely located with respect to the graphics surface on a main electronics board, the graphics surface having an insulative support substrate and a unique resistive layer to which the stylus is coupled, the unique resistive layer being coupled to the controller via a flex cable, the flex cable providing for electrical communications between the resistive layer and the controller, the controller accessing a memory device also remotely located with respect to the graphics surface on the main electronics board, wherein the memory device has calibration data to compensate for non-uniformities in unique resistive layer in determining the position of the stylus;

the improvement comprising;

an interface board attached to the flex cable and having signal lines coupled to the controller;

a memory device comprising the calibration data and being mounted on the interface board remotely located with respect to the main electronics board and being linked to the signal lines of the interface board for communications with the controller.

16. A method for manufacturing a graphics surface assembly comprising the steps of:

providing a graphics surface formed of a unique resistive layer and an insulative support structure, a flex cable having signal lines for communications with a controller located on a main electronics board and a memory device capable of communications with the controller;

attaching the flex cable to the graphics surface;

coupling the memory device to the flex cable such that the memory device is remotely located with respect to the main electronics board;

generating calibration data for compensating for the unique resistive layer; and

storing the calibration data in the memory device.

17. A method for manufacturing a field replaceable graphics surface assembly as claimed in claim 16 wherein the memory device is mounted on an interface board.

18. A method for manufacturing a field replaceable graphics surface assembly as claimed in claim 16 wherein the memory device is mounted on the flex cable.

19. In an electrographic system having a controller located on a main electronics board for providing position indications for a stylus positioned adjacent to a graphics surface having a unique resistive layer on a transparent support structure, a method for manufacturing a graphics surface assembly comprising the steps of:

mounting a read only memory device onto an interface board, the interface board having signal lines for communications between the memory device and the controller;

coupling the interface board to a flex cable, the flex cable having signal lines for communications between the graphics surface and the controller;

attaching the flex cable with the interface board coupled thereto to the graphics surface;

performing a calibration procedure with respect to the unique resistive layer of the graphics surface to generate data for compensating for the non-uniformities associated with unique resistive layer; and

storing the calibration data in the memory device, the memory device being mounted to the interface board, the interface board being coupled to the flex cable, and the flex cable being attached to the graphics surface.