Optical input type touch system and feedback control method thereof

• US 8,344,313 B2
• Filed: 10/06/2010
• Issued: 01/01/2013
• Est. Priority Date: 10/07/2005
• Status: Active Grant

• Current Assignee: Shanghai Xuanyang Electronic Technologies Inc.
• Original Assignee: Integrated Digital Technologies, Inc. (InterDigital, Inc.)
• Inventors: Hwang, Naejye, Fann, Sen-Shyong, Yuan, Chih-Ming, Liaw, Shen-Tai
• Primary Examiner(s): Bui Pho, Pascal M
• Application Number:
  US12/899,349
• Publication Number:
  US 20110018834A1
• Time in Patent Office: 818 Days
• Field of Search: 345/173, 345/175, 345/176, 345/178, 345/180, 250/221, 250/549, 250/214.R, 250/214.1, 250/214.AG, 250/214.AL, 250/214.C, 250/214.DC, 250/227.22, 178/18.01, 178/18.03, 178/18.09, 178/18.11
• US Class Current: 250/227.22
• CPC Class Codes: G02F 1/00 Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: H01L 27/00 Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate details thereof H01L23/00, H01L29/00 - H10K10/00; assemblies consisting of a plurality of individual solid state devices H01L25/00
• CPC Class Codes: H01L 31/00 Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof H10K30/00 takes precedence; devices consisting of a plurality of solid state components formed in, or on, a common substrate, other than combinations of radiation-sensitive components with one or more electric light sources, H01L27/00
• CPC Class Codes: H01L 31/1136 the device being a metal-insulator-semiconductor field-effect transistor
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof

Abstract

A touch system including a touch panel and a readout circuit is disclosed. The touch panel is integrated with a plurality of photosensitive elements within pixel elements, and capable of displaying at least touch position by at least an optical inputting. The touch panel provides a signal data when the touch panel is touched. The readout circuit is configured to receive the signal data and includes a transformation unit and a processing unit. The transformation unit generates a signal value based on the signal data and a transformation parameter. The processing unit executes a specific action when the signal value is less than a preset value.

Claims

1. An optical inputting type touch system, comprising:

a touch panel integrated with a plurality of photosensitive elements within pixel elements, and capable of displaying at least touch position by at least an optical inputting, wherein the touch panel provides a signal data generated by the photosensitive elements when the touch panel is touched;

a readout circuit configured to receive the signal data and comprising;

a transformation unit generating a signal value based on the signal data and a transformation parameter; and

a processing unit, when the signal value is less than the preset value, returning a command to the transformation unit to shift a following signal value in accordance with the difference between the signal value and the preset value until the transformation unit receives a next command.

2. The optical inputting type touch system as claimed in claim 1, wherein the signal data is analog form and the signal value is digital format.

3. The optical inputting type touch system as claimed in claim 1, wherein the processing unit returns the command to adjust the transformation parameter.

4. The optical inputting type touch system as claimed in claim 1, wherein the command is an offset or a gain value.

5. The optical inputting type touch system as claimed in claim 1, wherein the command is a feedback and the feedback is within a limited range of the touch panel lifetime.

6. The optical inputting type touch system as claimed in claim 1, wherein the preset value is on the basis of a background component in a dark condition.

7. The optical inputting type touch system as claimed in claim 1, further comprising a plurality of converters disposed between the touch panel and the readout circuit and capable of converting a current of the optical inputting to a part of signal data.

8. The optical inputting type touch system as claimed in claim 1, wherein the signal data includes a background component of an ambient light and a photo component of optical inputting.

9. A feedback control method for an optical inputting type touch panel comprising a plurality of photosensitive elements to sense an optical input by an user, comprising:

providing a signal value generated by the photosensitive elements to represent a light level of the optical inputting type touch panel;

comparing the signal value with a preset value; and

when the signal value is less than the preset value, returning a command to shift a following signal value in accordance with a difference between the signal value and the preset value until receiving a next command.

10. The feedback control method as claimed in claim 9, wherein the preset value is a constant.

11. The feedback control method as claimed in claim 9, wherein the signal value comprises photo component sensed by an embedded element in the optical inputting type touch panel.

12. The feedback control method as claimed in claim 9, wherein the command is within a limited range of the optical inputting type touch panel.

13. The feedback control method as claimed in claim 9, wherein the light level is ambient light illumination without optical inputting.

14. The feedback control method as claimed in claim 9, further comprising:

defining the preset value according to information of a dark condition.

15. The feedback control method as claimed in claim 9, further comprising:

discarding the signal value when the preset value is larger than the signal value, and shifting next signal values based on the difference between the preset value and the selected signal value.

16. The feedback control method as claimed in claim 9, further comprising:

outputting the signal value to a host device.