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US 8,803,846 B2Granted
Method for detecting touch and optical touch sensing system
AssigneeLG Display Co., Ltd.
InventorShi-Cheol Song
Life of this patent
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Abstract
An optical touch sensing method includes sensing light corresponding to a touch region, comparing a first amount of the light sensed corresponding to the touch region with a first lower threshold, determining that a touch is made if the first amount is less than or equal to the first lower threshold, comparing the first amount of the light sensed corresponding to the touch region with an upper threshold, and determining that a touch is made if the first amount is greater than or equal to the upper threshold.
Claims12
An optical touch sensing method, comprising:
- sensing light corresponding to a touch region of a display panel through an optical sensor module, wherein the optical sensor module includes infrared camera sensors provided to three or more than three corners of the display panel, and retro-reflecting plates formed at four sides of the display panel;
- comparing a first amount of the light sensed corresponding to the touch region with a first lower threshold;
- determining that a touch is made if the first amount is less than or equal to the first lower threshold;
- comparing the first amount of the light sensed corresponding to the touch region with an upper threshold, if the first amount is greater than the first lower threshold;
- determining that a touch is made if the first amount is greater than or equal to the upper threshold;
- sensing light corresponding to a particular touch region;
- comparing a second amount of the light sensed corresponding the particular touch region with a second lower threshold;
- and
- determining that a touch is made if the second amount is less than or equal to the second lower threshold,
- wherein the second lower threshold is higher than the first lower threshold, and
- wherein the particular touch region comprises a substantially triangular region having a first apex at an optical sensor, a second apex substantially at an end, closer to the optical sensor, of a retro-reflecting plate disposed on a long side of the touch region disposed away from the optical sensor, and a third apex at a point on the retro reflecting plate about three-eighths (⅜) of the length of retro-reflecting plate from the second apex, wherein the touch region is a rectangular shape having a length-to-width ratio of about sixteen to nine (16:9).
8 more elements
An optical touch sensing system, comprising:
- an optical sensor module operable to sense light corresponding to a touch region of a display panel, wherein the optical sensor module includes infrared camera sensors provided to three or more than three corners of the display panel, and retro-reflecting plates formed at four sides of the display panel;
- and
- a control unit coupled to the optical sensor module operable to:
- compare a first amount of the light sensed corresponding to the touch region with a first lower threshold,
- determine that a touch is made if the first amount is less than or equal to the first lower threshold,
- compare the first amount of the light sensed corresponding to the touch region with an upper threshold, if the first amount is greater than the first lower threshold, and
- determine that a touch is made if the first amount is greater than or equal to the upper threshold;
- wherein:
- the optical sensing module is further operable to sense light corresponding to a particular touch region;
- and
- the control unit is further operable to:
- compare a second amount of the light sensed corresponding the particular touch region with a second lower threshold, and
- determine that a touch is made if the second amount is less than or equal to the second lower threshold,
- wherein the second lower threshold is higher than the first lower threshold, and
- wherein the particular touch region comprises a substantially triangular region having a first apex at an optical sensor of the optical sensor module, a second apex substantially at an end closer to the optical sensor of a retro-reflecting plate disposed on a long side of the touch region disposed away from the optical sensor, and a third apex at a point on the retro reflecting plate about three-eighths (⅜) of the length of retro-reflecting plate from the second apex, wherein the touch region is a substantially rectangular shape having a length-to-width ratio of about sixteen to nine (16:9).
12 more elements
Dependencies are inferred from the claim text.