LCD panel with integral touchscreen
First Claim
1. A liquid crystal display (LCD) device, comprising:
- a casing configured to hold a transparent touchscreen surface in place;
a liquid crystal (LC) layer disposed within the casing behind the touchscreen surface;
a probe signal source disposed within the casing behind the LC layer, the probe signal source being configured to transmit a probe signal through the touchscreen surface, the probe signal source including a first probe light source and a second probe light source, each probe light source configured to emit light having a first and second frequency, respectively, wherein the first frequency is different than the second frequency;
a probe signal sensing device disposed within the casing behind the LC layer; and
a contact locating device configured to locate a point of contact on the touchscreen surface based on an increase in intensity of a reflection of the probe signal through the touchscreen surface as measured by the probe signal sensing device.
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Accused Products
Abstract
A liquid crystal display (LCD) device (100) having an integrated touchscreen includes a built-in probe signal source behind the liquid crystal (LC) layer (20). The probe signal source may include a pair of light sources (82 and 84) modulated at first and second frequencies (f1 and f2), respectively. A pair of probe light sensing devices (92 and 94) may also be implemented behind the LC layer, each configured to measure the intensities of the first and second frequencies, respectively. The probe light sensing devices are designed to detect user contact with the touchscreen surface by sensing a reflection of the probe light signals from the touchscreen surface. Using the multiple intensity measurements from each probe light sensing device, the location of the point of contact on the touchscreen surface is determined.
26 Citations
13 Claims
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1. A liquid crystal display (LCD) device, comprising:
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a casing configured to hold a transparent touchscreen surface in place; a liquid crystal (LC) layer disposed within the casing behind the touchscreen surface; a probe signal source disposed within the casing behind the LC layer, the probe signal source being configured to transmit a probe signal through the touchscreen surface, the probe signal source including a first probe light source and a second probe light source, each probe light source configured to emit light having a first and second frequency, respectively, wherein the first frequency is different than the second frequency; a probe signal sensing device disposed within the casing behind the LC layer; and a contact locating device configured to locate a point of contact on the touchscreen surface based on an increase in intensity of a reflection of the probe signal through the touchscreen surface as measured by the probe signal sensing device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A liquid crystal display (LCD) device, comprising:
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a casing configured to hold a transparent touchscreen surface in place; a liquid crystal (LC) layer disposed within the casing behind the touchscreen surface; first and second light-emitting diodes (LEDs) disposed within the casing behind the LC layer, the first and second LEDs being configured to transmit a first and a second probe light, respectively, through the touchscreen surface, the first probe light and the second probe light having a first and second frequency, wherein the first frequency is different than the second frequency; first and second light sensing devices disposed within the casing behind the LC layer, each configured to measure intensities of both the first and second probe lights; and a processing device configured to detect a point of contact on the touchscreen surface by calculating location coordinates from which the first and second probe signals are reflected back to the first and second light sensing devices based on an increase in the measured intensities.
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Specification