CHOLESTERIC LIQUID CRYSTAL TOUCH DISPLAY PANEL AND TOUCH POSITIONING METHOD THEREOF

• US 20130207908A1
• Filed: 05/15/2012
• Published: 08/15/2013
• Est. Priority Date: 02/10/2012
• Status: Abandoned Application

• Current Assignee: Chunghwa Picture Tubes Limited (Tatung Co., Ltd.)
• Original Assignee: Chunghwa Picture Tubes Limited (Tatung Co., Ltd.)
• Inventors: Chang, Ming-Tse, Su, Chun-Wei
• Application Number:
  US13/471,465
• Publication Number:
  US 20130207908A1
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/13718 based on a change of the texture state of a cholesteric liquid crystal
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A cholesteric liquid crystal touch display panel includes an upper substrate, a lower substrate, a cholesteric liquid crystal display layer, and a color sensor array. The cholesteric liquid crystal display layer is disposed between the upper substrate and the lower substrate. The cholesteric liquid crystal display layer includes a plurality of liquid crystal display units, which are used to reflect light within a wavelength range and allow light beyond the wavelength range to pass through. The color sensor array is disposed between the cholesteric liquid crystal display layer and the lower substrate. The color sensor array includes a plurality of color sensors. Each of the color sensors is disposed correspondingly to at least one liquid crystal display unit. Each of the color sensors is used to sense variations of light from the corresponding liquid crystal display unit.

Claims

1. A cholesteric liquid crystal touch display panel, comprising:

an upper substrate;

a lower substrate, disposed correspondingly to the upper substrate;

a cholesteric liquid crystal display layer, disposed between the upper substrate and the lower substrate, wherein the cholesteric liquid crystal display layer comprises a plurality of liquid crystal display units, and the liquid crystal display units are used to reflect light within a wavelength range and allow light beyond the wavelength range to pass through; and

a color sensor array, disposed between the cholesteric liquid crystal display layer and the lower substrate, the color sensor array comprising a plurality of color sensors, wherein each of the color sensors is disposed correspondingly to at least one liquid crystal display unit, and each of the color sensors is used to sense variations of light from the corresponding liquid crystal display unit.

2. The cholesteric liquid crystal touch display panel of claim 1, wherein each of the color sensors comprises a color filter for sensing light within a specific wavelength range.

3. The cholesteric liquid crystal touch display panel of claim 1, wherein each of the color sensors comprises at least one first color sensor unit, at least one second color sensor unit, and at least one third color sensor unit for respectively sensing light within different wavelength ranges, and the first color sensor unit, the second color sensor unit, and the third color sensor unit within one color sensor are respectively disposed correspondingly to three adjacent liquid crystal display units.

4. The cholesteric liquid crystal touch display panel of claim 3, wherein the liquid crystal display units disposed correspondingly to the first color sensor unit, the second color sensor unit, and the third color sensor unit within one color sensor are used to reflect light within the same wavelength range.

5. The cholesteric liquid crystal touch display panel of claim 3, wherein the liquid crystal display units disposed correspondingly to the first color sensor unit, the second color sensor unit, and the third color sensor unit within one color sensor are used to reflect light within different wavelength ranges.

6. The cholesteric liquid crystal touch display panel of claim 1, wherein the liquid crystal display units are aligned in an array configuration, and the liquid crystal display units comprise at least one first liquid crystal display unit, at least one second liquid crystal display unit, and at least one third liquid crystal display unit for reflecting light within different wavelength ranges.

7. The cholesteric liquid crystal touch display panel of claim 1, wherein each of the color sensors further comprises a converting device, and the converting device is used to convert the received light into output voltage.

8. A touch positioning method of a cholesteric liquid crystal touch display panel, comprising:

providing the cholesteric liquid crystal touch display panel of claim 1, wherein each of the color sensors comprises a converting device, and the converting device is used to convert the received light into output voltage;

inputting a display signal into the cholesteric liquid crystal display layer to present a display image, and obtaining the output voltage corresponding to the display image by the color sensors simultaneously;

monitoring variations of the output voltage from each of the color sensors to determine whether the cholesteric liquid crystal touch display panel is touched or not; and

calculating the variations of the output voltage from each of the color sensors to define a touched region in the cholesteric liquid crystal touch display panel.

9. The touch positioning method of the cholesteric liquid crystal touch display panel of claim 8, further comprising:

calculating variations of the output voltage from each of the color sensors within the touched region; and

regarding a position of the color sensor with the largest output voltage variation as a touch center point.

10. The touch positioning method of the cholesteric liquid crystal touch display panel of claim 8, further comprising regarding a center position of the touched region as a touch center point.