Fingerprint sensing pixel with a larger aperture

• US 20050219200A1
• Filed: 03/31/2004
• Published: 10/06/2005
• Est. Priority Date: 03/31/2004
• Status: Abandoned Application

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Weng, Chien-Sen
• Application Number:
  US10/813,987
• Publication Number:
  US 20050219200A1
• Time in Patent Office: Days
• US Class Current: 345/104
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 2203/0338 Fingerprint track pad, i.e. fingerprint sensor used as pointing device tracking the fingertip image
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface

Abstract

In a thin film transistor-based resistive-type fingerprinting touch screen panel, the size of the contact metal layer connecting the drain electrode of the TFT and the ITO sensing electrode in each of the pixel regions of the touch screen panel is reduced, thus increasing the aperture of the pixel region. Having a greater aperture, more of the backlighting from the LCD display panel usually positioned behind the touch screen panel is transmitted through the touch screen panel, making that region brighter.

Claims

1. A sensing pixel of a thin film transistor-based resistive-type fingerprinting touch screen panel, the sensing pixel comprising:

a thin film transistor having a poly-Si film layer forming a channel region and at least one drain electrode connecting the poly-Si film layer to a contact metal pad;

a sensing electrode connected to the contact metal pad through a via, wherein at least a portion of the via overlaps the poly-Si film layer when viewed through the sensing electrode.

2. The sensing pixel of claim 1, wherein a substantial portion of the via overlaps the poly-Si film layer when viewed through the sensing electrode.

3. The sensing pixel of claim 1, wherein the sensing electrode comprises indium tin oxide or indium zinc oxide.

4. The sensing pixel of claim 1, wherein the sensing pixel having an aperture ratio of greater than about 80%.

13. The sensing pixel of claim 1, wherein the sensing electrode is transparent.

5. A thin film transistor-based resistive-type fingerprinting touch screen panel comprising:

an upper substrate;

a lower substrate beneath the upper substrate, wherein the lower substrate comprises an array of thin film transistor-based sensing pixels, each of the sensing pixels comprising;

a thin film transistor having a poly-Si film layer forming a channel region and at least one drain electrode connecting the poly-Si film layer to a contact metal pad;

a sensing electrode connected to the contact metal pad through a via, wherein at least a portion of the via overlaps the poly-Si film layer when viewed through the sensing electrode.

6. The touch screen panel of claim 5, wherein a substantial portion of the via overlaps the poly-Si film layer.

7. The touch screen panel of claim 5, wherein the sensing electrode comprises indium tin oxide or indium zinc oxide.

8. The touch screen panel of claim 5, wherein the sensing pixel having an aperture ratio of greater than about 80%.

14. The touch screen panel of claim 5, wherein the sensing electrode is transparent.

16. The touch screen panel of claim 5, wherein the upper substrate is made of PET.

9. A display system having a fingerprinting feature comprising:

a LCD panel;

a backlight for the LCD panel;

a thin film transistor-based resistive-type fingerprinting touch screen panel over the LCD panel, wherein the thin film transistor-based resistive-type fingerprinting touch screen panel comprises;

an upper substrate;

a lower substrate beneath the upper substrate, wherein the lower substrate comprises an array of thin film transistor-based sensing pixels, each of the sensing pixels comprising;

a thin film transistor having a poly-Si film layer forming a channel region and at least one drain electrode connecting the poly-Si film layer to a contact metal pad;

a sensing electrode connected to the contact metal pad through a via, wherein at least a portion of the via overlaps the poly-Si film layer when viewed through the sensing electrode.

10. The touch screen panel of claim 9, wherein a substantial portion of the via overlaps the poly-Si film layer.

11. The touch screen panel of claim 9, wherein the sensing electrode comprises indium tin oxide or indium zinc oxide.

12. The touch screen panel of claim 9, wherein the sensing pixel having an aperture ratio of greater than 80%.

15. The touch screen panel of claim 9, wherein the sensing electrode is transparent.

17. The touch screen panel of claim 9, wherein the upper substrate is made of PET.