POSITION DETECTING DEVICE

• US 20100110029A1
• Filed: 10/16/2009
• Published: 05/06/2010
• Est. Priority Date: 10/31/2008
• Status: Active Grant

• Current Assignee: Wacom Co Limited (Wacom)
• Original Assignee: Wacom Co Limited (Wacom)
• Inventors: Yamamoto, Sadao, Onoda, Naoto
• Granted Patent: US 8,780,056 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0444 using a single conductive element covering the whole sensing surface, e.g. by sensing the electrical current flowing at the corners
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 3/3453 based on rotating particles or microelements

Abstract

A position detecting device includes: a display unit having a first electrode formed of a transparent conductive film, a plurality of second electrodes, and display material interposed between the first electrode and the second electrodes; a display driver configured to drive the display unit based on a video signal input to the display driver; and a position detecting section configured to detect a position of an indicator on the first electrode and to output the detected position. The display unit may comprise, for example, an “electronic paper,” such that the display state of the display unit can be maintained even after a drive power applied between the first electrode and the second electrodes is discontinued.

Claims

1. A position detecting device comprising:

a display unit which has a first electrode formed of a transparent conductive film, a plurality of second electrodes, and display material interposed between the first electrode and the plurality of second electrodes;

a display driver configured to drive the display unit based on a video signal input to the display driver; and

a position detecting section configured to detect a position indicated on the first electrode by an indicator and to output a detected position signal,

wherein the display unit is configured to maintain a display state when a drive power applied between the first electrode and the second electrodes is discontinued.

2. The position detecting device according to claim 1, further comprising a switch for selectively connecting the display driver or the position detecting section to the first electrode.

3. The position detecting device according to claim 1, wherein the position detecting section is an electrostatic coupling type position detecting section.

4. The position detecting device according to claim 3, wherein the first electrode includes a plurality of sensors arranged into a matrix.

5. The position detecting device according to claim 3, wherein the indicator is at least one of a human finger and an electrostatic coupling type position indicator, and the position detecting device is configured to detect a position where the indicator and the first electrode are electrostatically coupled with each other.

6. The position detecting device according to claim 4, wherein the indicator is at least one of a human finger and an electrostatic coupling type position indicator, and the position detecting device is configured to detect a position where the indicator and the first electrode are electrostatically coupled with each other.

7. The position detecting device according to claim 1, wherein the position detecting section is a resistance film type position detecting section.

8. The position detecting device according to claim 1, wherein the first electrode includes a plurality of sensors arranged into a matrix, and the position detecting section is an electromagnetic induction type position detecting section.

9. The position detecting device according to claim 8, wherein the indicator is an electromagnetic induction type position indicator having a resonant circuit configured by a coil and a capacitor.

10. The position detecting device according to claim 1, wherein, when the indicator is detected by the position detecting section, the display driving operation performed by the display driver is stopped so that operation for detecting the position indicated by the indicator is performed.

11. The position detecting device according to claim 10, wherein, when the video signal is input to the display driver during the time while the position detecting operation is being performed by the position detecting section, the display driver performs the display driving operation after the position detecting operation being performed is completed.

12. The position detecting device according to claim 1, wherein the position of the indicator on the first electrode is detected by the position detecting section constantly in the absence of the video signal, and, in the presence of the video signal, the position of the indicator on the first electrode is detected by the position detecting section in a time-sharing mode with the display driver driving the display unit.

13. The position detecting device according to claim 12, wherein the display driver comprises a display driving controller configured to control the time-sharing mode of operation of the position detecting section and the display driver.

14. The position detecting device according to claim 13, wherein the display driving controller is further configured to selectively connect the display driver or the position detecting section to the first electrode.

15. A method for detecting a position on a display unit, wherein the display unit has a first electrode formed of a transparent conductive film, a plurality of second electrodes, and display material interposed between the first electrode and the plurality of second electrodes, the method comprising:

driving the display unit based on a video signal;

maintaining a display state of the display unit when a drive power applied between the first electrode and the second electrodes is discontinued; and

detecting a position indicated on the first electrode by an indicator and outputting a detected position signal.

16. The method of claim 15, further comprising selectively performing either the driving of the display unit or the detecting of a position at any given time.

17. The method of claim 16, wherein, when the video signal is received during the time while the detecting of a position is being performed, the driving of the display unit is performed after the detecting of a position is completed.

18. The method of claim 15, wherein the detecting of a position is performed constantly in the absence of the video signal, and, in the presence of the video signal, the detecting of a position is performed in a time-sharing mode with the driving of the display unit.