U.S. patent application number 12/896911 was filed with the patent office on 2011-01-27 for touch panel.
Invention is credited to Chi-Wen Chen, Min-Feng Chiang, Hsin-Hung Lee, Chun-Hsin Liu, Po-Yuan Liu.
Application Number | 20110018842 12/896911 |
Document ID | / |
Family ID | 40294882 |
Filed Date | 2011-01-27 |
United States Patent
Application |
20110018842 |
Kind Code |
A1 |
Lee; Hsin-Hung ; et
al. |
January 27, 2011 |
Touch Panel
Abstract
A touch panel includes a plurality of first pixels and second
pixels. Each first pixel has a light sensing component for sensing
light then generating a first sensing signal and a switch. The
switch contains a first end coupled to the light sensing component,
a control end for receiving a first gate driving signal, and a
second end for transmitting the first sensing signal according to
the first gate driving signal. Each second pixel includes a
pressure sensing component for sensing pressure then generating a
second sensing signal and a switch. The switch contains a first end
coupled to the pressure sensing component, a control end for
receiving a second gate driving signal, and a second end for
transmitting the second sensing signal according to the second gate
driving signal.
Inventors: |
Lee; Hsin-Hung; (Hsin-Chu,
TW) ; Liu; Po-Yuan; (Hsin-Chu, TW) ; Chiang;
Min-Feng; (Hsin-Chu, TW) ; Liu; Chun-Hsin;
(Hsin-Chu, TW) ; Chen; Chi-Wen; (Hsin-Chu,
TW) |
Correspondence
Address: |
NORTH AMERICA INTELLECTUAL PROPERTY CORPORATION
P.O. BOX 506
MERRIFIELD
VA
22116
US
|
Family ID: |
40294882 |
Appl. No.: |
12/896911 |
Filed: |
October 3, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11934784 |
Nov 5, 2007 |
|
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12896911 |
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Current U.S.
Class: |
345/175 |
Current CPC
Class: |
G06F 3/042 20130101;
G06F 3/0447 20190501; G06F 3/0412 20130101; G06F 2203/04106
20130101; G06F 3/044 20130101 |
Class at
Publication: |
345/175 |
International
Class: |
G06F 3/042 20060101
G06F003/042 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 26, 2007 |
TW |
096127317 |
Claims
1. A touch panel comprising: a plurality of first pixels, each
first pixel comprising: a light sensing component for sensing light
then generating a first sensing signal; and a switch, comprising: a
first end coupled to the light sensing component; a control end for
receiving a first gate driving signal; and a second end for
transmitting the first sensing signal according to the first gate
driving signal; and a plurality of second pixels, each second pixel
comprising: a pressure sensing component for sensing pressure then
generating a second sensing signal; and a switch, comprising: a
first end coupled to the pressure sensing component; a control end
for receiving a second gate driving signal; and a second end for
transmitting the second sensing signal according to the second gate
driving signal.
2. The touch panel of claim 1, further comprising a plurality of
gate lines for transmitting a plurality of first and second gate
driving signals to the switches of the plurality of the first and
the second pixels, respectively.
3. The touch panel of claim 1, further comprising a plurality of
data reading lines, each of the data reading lines coupled to the
second ends of the switches of corresponding first and second
pixels for transmitting the first sensing signals or the second
sensing signals.
4. The touch panel of claim 1, wherein the light sensing component
comprises a photo transistor including: a first end for receiving a
first voltage; a control end coupled to the first end of the photo
transistor; and a second end coupled to the first end of the switch
of a corresponding first pixel.
5. The touch panel of claim 1, wherein the pressure sensing
component comprises a variable capacitor including: a first end
coupled to the first end of the switch of a corresponding second
pixel; and a second end for receiving a second voltage; wherein
capacitance of the variable capacitor changes when the variable
capacitor is pressed.
6. The touch panel of claim 1, further comprising a plurality of
detecting circuits for receiving the first sensing signals and the
second sensing signals transmitted from the plurality of data
reading lines.
7. The touch panel of claim 6, wherein each of the detecting
circuits comprises: an amplifier, comprising: a positive input end
for receiving a reference voltage; a negative input end coupled to
the second end of the switch of a corresponding first pixel; and an
output end for outputting an output voltage according to a
corresponding first sensing signal and a corresponding second
sensing signal; a capacitor coupled between the output end of the
amplifier and the negative input end of the amplifier; and a switch
coupled between the output end of the amplifier and the negative
input end of the amplifier for coupling the output end of the
amplifier to the negative input end of the amplifier when the
corresponding first pixel receives the corresponding first gate
driving signal.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. application Ser. No.
11/934,784 filed Nov. 5, 2007, and hereby incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a touch panel, and more
particularly, to a touch panel with pixels wherein each pixel has
light sensing components and pressure sensing components.
[0004] 2. Description of the Prior Art
[0005] Please refer to FIG. 1. FIG. 1 is a diagram illustrating a
pixel Pa of a conventional touch panel. As shown in FIG. 1, the
pixel Pa comprises a switch SW and a photo sensing component PT.
The switch SW can be realized with a Thin Film Transistor (TFT).
The light sensing component PT can be realized with a photo
transistor or photo diode. One end of the light sensing component
PT is coupled to the second end of the switch SW, and the other end
of the light sensing component PT is coupled to a bias voltage
source Vb. When the light sensing component PT senses light, which
means the pixel Pa is not touched, the current I is generated and
pulls down the voltage Va to voltage Vb. On the other hand, when
the light sensing component does not sense light, which means the
pixel Pa is touched, the current I is not generated and the voltage
Va keeps at the same level. The control end of the switch SW is
coupled to the corresponding gate line of the pixel Pa, and the
first end of the switch SW is coupled to the corresponding data
reading line of the pixel Pa, whereas the second end of the switch
SW is coupled to one end of the light sensing component. The switch
SW couples the first end of the switch SW to the second end of the
switch SW when receiving the gate driving signal from the
corresponding gate line, and thus the corresponding data reading
line of the pixel Pa receives the voltage Va. In this way, the
conventional touch panel determines if the pixel Pa is touched
according to the level of the voltage Va.
[0006] However, the drawback of the conventional touch panel is
that when there is no ambient light around the conventional touch
panel, the light sensing component PT can not sense the variation
of light. Hence the conventional touch panel can not determine if
the pixel Pa is touched. In this situation, the application of the
conventional touch panel is limited.
SUMMARY OF THE INVENTION
[0007] The present invention provides a touch panel. The touch
panel comprises a plurality of first pixels and second pixels. Each
first pixel comprises a light sensing component for sensing light
then generating a first sensing signal and a switch. The switch
comprises a first end coupled to the light sensing component, a
control end for receiving a first gate driving signal, and a second
end for transmitting the first sensing signal according to the
first gate driving signal. Each second pixel comprises a pressure
sensing component for sensing pressure then generating a second
sensing signal and a switch. The switch comprises a first end
coupled to the pressure sensing component, a control end for
receiving a second gate driving signal, and a second end for
transmitting the second sensing signal according to the second gate
driving signal.
[0008] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a diagram illustrating a pixel of a conventional
touch panel.
[0010] FIG. 2 is a diagram illustrating a pixel of the touch panel
of the present invention.
[0011] FIG. 3 is another pixel of the present invention.
[0012] FIG. 4 is a touch panel according to a first embodiment of
the present invention.
[0013] FIG. 5 is a touch panel according to a second embodiment of
the present invention.
DETAILED DESCRIPTION
[0014] Please refer to FIG. 2. FIG. 2 is a diagram illustrating a
pixel Pb of the touch panel of the present invention. As shown in
FIG. 2, the pixel Pb is similar to the pixel Pa and the description
of the same components is omitted. The difference between the pixel
Pa and Pb is that the pixel Pb further comprises a variable
capacitor Cv coupled to the second end of the switch SW. One end of
the variable capacitor Cv is coupled to the second end of the
switch SW, and the other end of the variable capacitor Cv is
coupled to a common end Vcom (the common end carries a voltage).
When the pixel Pb is touched, the capacitance of the variable
capacitor Cv is changed, and consequently the voltage Va is
affected. In this way, when the pixel Pb is not touched, the light
sensing component PT generates the current I to change the level of
the voltage Va; when the pixel Pb is touched, the light sensing
component PT does not generate the current but the capacitance of
the variable capacitor Cv is changed so that the level of the
voltage Va is also changed. In other word, the pixel Pb can
determine if touched whether there is ambient light or not.
[0015] Additionally, in FIG. 2, at the corresponding data reading
line of the pixel Pb, an integrator 210 (detecting circuit) is
coupled for detecting if the pixel Pb is touched. The integrator
210 comprises a switch SW2, a capacitor Cfb, and an amplifier 211.
The positive input end of the amplifier 211 is coupled to a
reference voltage source for receiving a reference voltage Vref.
The negative input end of the amplifier 211 is coupled to the
corresponding data reading line. The output end of the amplifier
211 is disposed for outputting an output voltage Vout. The switch
SW2 is coupled between the negative input end and the output end of
the amplifier 211. The capacitor Cfb is coupled between the
negative input end and the output end of the amplifier 211. When
the pixel Pb receives the corresponding gate driving signal, the
switch is turned off (disconnected). When the pixel Pb does not
receive the corresponding gate driving signal, the switch is turned
on (connected) so that the negative input end of the amplifier 211
is coupled to the output end of the amplifier 211.
[0016] When the capacitor Cv is not touched (that is, not pressed),
it has a capacitance value of Cst1; when the capacitor Cv is
touched (pressed), the capacitance value is Cst2. The charge
maximum Q (max) of the variable capacitor Cv can store is:
Q(max)=Cst1(Vref-Vcom). The maximum output voltage Vout(max)
is:
Vout(max)=Cst1(Vref-Vcom)/Cfb. When the pixel Pb is not touched,
which means the light sensing component PT senses light, the output
voltage of the integrator 210 is:
Vout = Cst 1 ( Va ( t ) - Vcom ) / Cfb = .intg. 0 0 + Tf I ( t ) t
/ Cfb .apprxeq. I .times. Tf / Cfb , ##EQU00001##
wherein Va(t) designates the voltage Va, Tf designates a timeframe,
and I designates the current generated by the photo transistor PT.
When the pixel Pb is touched, which means the light sensing
component PT senses no light, the output voltage of the integrator
210 is: Vout=(Cst2-Cst1) (Vcom-Vref)/Cfb. From the two expressions
described above, it is understood that the output voltage of the
integrator 210 differs between the pixel Pb being touched and the
pixel Pb being not touched. Therefore the pixel Pb can be
efficiently determined that it is touched or not.
[0017] Please refer to FIG. 3. FIG. 3 is another embodiment of the
present invention. The pixel Pc is similar to pixel Pb, and the
difference between the pixels Pc and Pb is that pixel Pc does not
comprise a light sensing component PT. In this way, the pixel Pc
can determine if it is touched directly according to a capacitance
change of the variable capacitor Cv, which saves the expense of the
light sensing component PT.
[0018] Please refer to FIG. 4. FIG. 4 is a touch panel 400
according to a first embodiment of the present invention. As shown
in FIG. 4, the touch panel 400 comprises a gate driving circuit
410, a data reading circuit 420, a plurality of integrators
(detecting circuits) 210, and a plurality of pixels Pb. The gate
driving circuit 410 transmits the gate driving signals S1, S2, S3,
and so on, to the corresponding pixels. The data reading circuit
420 detects if the corresponding pixels are touched according to
the respective gate driving signal. In this way, the touch panel
400 can efficiently determine the touched pixels, increasing the
utility and convenience.
[0019] Please refer to FIG. 5. FIG. 5 is a touch panel 500
according to the second embodiment of the present invention. As
shown in FIG. 5, the touch panel 500 comprises a gate driving
circuit 410, a data reading circuit 420, a plurality of integrator
210, and a plurality of pixels Pa and Pc. The gate driving circuit
410 transmits the gate driving signals S1, S2, S3, and so on,
respectively to the corresponding pixels. The data reading circuit
420 detects if the corresponding pixels are touched according to
the corresponding gate driving signal. In this way, the touch panel
500 can efficiently determine the touched pixels, increasing the
utility and convenience of the touch panel.
[0020] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *