Sensing an object with a plurality of conductors

• US 20040003949A1
• Filed: 07/05/2002
• Published: 01/08/2004
• Est. Priority Date: 07/05/2002
• Status: Active Grant

• Current Assignee: Sentelic Holding Company Limited
• Original Assignee: Sentelic Corporation
• Inventors: Lin, Jaoching
• Granted Patent: US 6,891,531 B2
• Time in Patent Office: Days
• US Class Current: 178/18.01
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

An object (130), e.g. a human finger or a stylus, is sensed with a plurality of conductors (120, X1, . . . XN). The conductor processing times (TX1, TX2, . . . TXN) but are shifted relative to one other.

Claims

1. A method for sensing an object with a plurality of conductors, wherein the object is capable of changing one or more characteristics of each of said conductors, the method comprising processing each conductor to determine its one or more characteristics;

wherein the processing of at least one of the conductors and the processing of at least another one of the conductors overlap but are shifted in time relative to each other.

2. The method of claim 1 wherein the processing of each conductor comprises generating a signal indicative of the conductor'"'"'s capacitance.

3. The method of claim 1 wherein the one or more characteristics of each conductor are indicative of a presence of the object adjacent to the conductor.

4. The method of claim 1 wherein the conductors are located at a surface, and the one or more characteristics of each conductor are indicative of a pressure of the object on the surface at a location proximate to the conductor.

5. The method of claim 1 wherein the processing of each conductor comprises generating and sensing a signal on the conductor and/or on a node coupled to the conductor, the signal indicating at least one of the one of more characteristics of the conductor;

and

for at least two conductors, an operation of generating and sensing the signal for one of the two conductors and an operation of generating and sensing the signal for the other one of the two conductors overlap but are shifted in time relative to each other.

6. The method of claim 5 wherein for each conductor, generating a corresponding signal comprises:

placing the conductor and/or the corresponding node into a predefined initial state; and

then

coupling the conductor and/or the node to a circuit that changes the conductor'"'"'s and/or node'"'"'s state, and generating a signal that represents the changed state or a parameter of a state changing process.

7. The method of claim 6 wherein each of said states is a voltage on the conductor and/or the node.

8. An apparatus for sensing an object with a plurality of conductors, wherein the object is capable of changing one or more characteristics of each of said conductors, the apparatus comprising circuitry which is to be coupled to the conductors and to process each conductor to determine the conductor'"'"'s one or more characteristics;

wherein the circuitry is to overlap the processing of at least one of the conductors with the processing of at least another one of the conductors while shifting in time the processing of said one of the conductors and the processing of said other one of the conductors relative to each other.

9. The apparatus of claim 8 wherein the processing of each conductor comprises generating a signal indicative of the conductor'"'"'s capacitance.

10. The apparatus of claim 8 in combination with the conductors, wherein the one or more characteristics of each conductor are indicative of a presence of the object adjacent to the conductor.

11. The apparatus of claim 8 in combination with the conductors, wherein the conductors are located at a surface, and the one or more characteristics of each conductor are indicative of a pressure of the object on the surface at a location proximate to the conductor.

12. The apparatus of claim 8 wherein the processing of each conductor comprises said circuitry generating and sensing a signal on the conductor and/or on a node coupled to the conductor, the signal indicating at least one of the one of more characteristics of the conductor;

and

for at least two conductors, an operation of generating and sensing the signal for one of the two conductors and an operation of generating and sensing the signal for the other one of the two conductors overlap but are shifted in time relative to each other.

13. The apparatus of claim 12 wherein for each conductor, generating a corresponding signal comprises:

placing the conductor and/or the corresponding node into a predefined initial state; and

then

coupling the conductor and/or the node to a circuit which forms part of said circuitry and which changes the conductor'"'"'s and/or node'"'"'s state, and generating a signal that represents the changed state or a parameter of a state changing process.

14. The apparatus of claim 13 wherein each of said states is a voltage on the conductor and/or the node.

15. The apparatus of claim 8 wherein the circuitry comprises:

a selection circuit for selecting a group of less than all conductors out of said plurality of the conductors; and

a processing circuit for processing the conductors in the selected group to generate signals indicative of the one or more characteristics of the selected conductors;

wherein the selection circuit is operable to select more than one conductors for said group, and to process the conductors in the selected group simultaneously while shifting in time the processing of at least two conductors in the group relative to each other; and

the circuitry further comprises a control circuit for controlling the selection circuit and the processing circuit to deselect a selected conductor whose processing has been completed without deselecting the conductor or conductors whose processing has not been completed, and to select and start the processing of another conductor without deselecting the conductor or conductors whose processing has not been completed.