Active matrix type display apparatus method for driving the same, and display element
First Claim
1. A display apparatus, comprising:
- a plurality of pixel electrodes arranged in a matrix;
switching elements connected thereto;
scanning electrodes;
video signal electrodes;
common electrodes;
a counter electrode;
a display medium interposed between the pixel electrodes and the counter electrode; and
storage capacitance formed between the pixel electrodes and the common electrodes,wherein, in a case where a scanning electrode-pixel electrode capacitance between the pixel electrodes and the scanning electrodes is represented by Cgd, a common electrode-pixel electrode capacitance between the pixel electrodes and the common electrodes is represented by Cst, and a total capacitance connected electrically to the pixel electrodes is represented by Ctot, α
gd and α
st represented by
α
gd=Cgd/Ctot, α
st=Cst/Ctot
(Formula
1)
are set to be different values between a portion close to feeding ends in a screen and a portion away therefrom, and an area of overlapping portions between the scanning electrodes and the pixel electrodes, and an area of overlapping portions between the common electrodes and the pixel electrodes are set to be larger in a screen center portion farthest from the feeding ends than in a screen end portion closest to the feeding ends, so that α
gd and α
st are both larger in the screen center portion farthest from the feeding ends than in the screen end portion closest to the feeding ends.
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Accused Products
Abstract
An active matrix type display apparatus is provided that is inexpensive, has less crosstalk, has no flickering and a brightness gradient, and is suitable for a large screen size. The display apparatus includes a plurality of pixel electrodes arranged in a matrix, switching elements (TFTs) connected thereto, scanning electrodes, video signal electrodes, common electrodes, and a counter electrode, wherein liquid crystal, for example, is interposed between the pixel electrodes and the counter electrode. Assuming that a gate-drain capacitance is Cgd, a common electrode-pixel electrode capacitance is Cst, and the total capacitance connected to the pixel electrodes is Ctot in this configuration, αgd and αst represented by αgd=Cgd/Ctot, αst=Cst/Ctot are set to be different values between a portion close to feeding ends in a screen and a portion away therefrom.
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Citations
22 Claims
-
1. A display apparatus, comprising:
- a plurality of pixel electrodes arranged in a matrix;
switching elements connected thereto;
scanning electrodes;
video signal electrodes;
common electrodes;
a counter electrode;
a display medium interposed between the pixel electrodes and the counter electrode; and
storage capacitance formed between the pixel electrodes and the common electrodes,wherein, in a case where a scanning electrode-pixel electrode capacitance between the pixel electrodes and the scanning electrodes is represented by Cgd, a common electrode-pixel electrode capacitance between the pixel electrodes and the common electrodes is represented by Cst, and a total capacitance connected electrically to the pixel electrodes is represented by Ctot, α
gd and α
st represented by
α
gd=Cgd/Ctot, α
st=Cst/Ctot
(Formula
1)
are set to be different values between a portion close to feeding ends in a screen and a portion away therefrom, andan area of overlapping portions between the scanning electrodes and the pixel electrodes, and an area of overlapping portions between the common electrodes and the pixel electrodes are set to be larger in a screen center portion farthest from the feeding ends than in a screen end portion closest to the feeding ends, so that α
gd and α
st are both larger in the screen center portion farthest from the feeding ends than in the screen end portion closest to the feeding ends. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- a plurality of pixel electrodes arranged in a matrix;
-
14. A display apparatus, comprising:
-
a plurality of pixel electrodes arranged in a matrix;
switching elements connected thereto;
scanning electrodes;
video signal electrodes;
common electrodes;
a counter electrode;
a display medium interposed between the pixel electrodes and the counter electrode;
storage capacitance formed between the pixel electrodes and the common electrodes;
a video signal driving circuit for applying two kinds of video signals having different polarities to video signal electrodes in accordance with a display period; and
a common electrode potential control circuit for applying a voltage signal to a plurality of common electrodes and a scanning signal driving circuit for applying a voltage signal to a plurality of scanning electrodes, the common electrode potential control circuit has output potential levels of at least two values, and the scanning signal driving circuit has output potential levels of at least two values, wherein, in a vase where a scanning electrode-pixel electrode capacitance between the pixel electrodes and the scanning electrodes is represented by Cgd, a common electrode-pixel electrode capacitance between the pixel electrodes and the common electrodes is represented by Cst, and a total capacitance connected electrically to the pixel electrodes is represented by Ctot, α
gd and α
st represented by
α
gd=Cgd/Ctot, α
st=Cst/Ctot
(Formula
1)
are set to be different values between a portion close to feeding ends in a screen and a portion away therefrom,a potential of a scanning electrode becomes a first potential level Vgon when the scanning electrode is selected and becomes substantially a second potential level Vgoff during a retention period in which the scanning electrode is not selected, a potential of a common electrode that is a connection destination of storage capacitance connected to pixel electrodes of a plurality of pixels belonging to the scanning electrode becomes a first potential level Vc(+) in a ease where a polarity of a video signal is positive and a second potential level Vc(−
) in a case where the polarity of the video signal is negative, when the scanning electrode is selected, andin a case where a difference between the first potential level Vc(+) of the common electrode and a potential during a subsequent retention period is represented by Δ
Vc(+), and a difference between the second potential level Vc(−
) of the common electrode and a potential during a subsequent retention period is represented by Δ
Vc(−
),γ
represented by
γ
=α
stVcp/2
(Formula
2)
(where Vcp=Δ
Vc(+)−
Δ
Vc(−
)
(Formula
3))
is set to be smaller in the portion away from the feeding ends in the screen, compared with the portion close thereto. - View Dependent Claims (15, 16, 17)
-
-
18. A display apparatus, comprising:
-
a plurality of pixel electrodes arranged in a matrix;
switching elements connected thereto;
scanning electrodes;
video signal electrodes;
common electrodes;
a counter electrode;
a display medium interposed between the pixel electrodes and the counter electrode;
storage capacitance formed between the pixel electrodes and the common electrodes;
a video signal driving circuit for applying two kinds of video signals having different polarities to video signal electrodes in accordance with a display period; and
a common electrode potential control circuit for applying a voltage signal to a plurality of common electrodes mid a scanning signal driving circuit for applying a voltage signal to a plurality of scanning electrodes, the common electrode potential control circuit has output potential levels of at least two values, and the scanning signal driving circuit has output potential levels of at least two values, wherein, in a case where a scanning electrode-pixel electrode capacitance between the pixel electrodes and the scanning electrodes is represented by Cgd, a common electrode-pixel electrode capacitance between the pixel electrodes and the common electrodes is represented by Cst, and a total capacitance connected electrically to the pixel electrodes is represented by Ctot, α
gd and α
st represented by
α
gd=Cgd/Ctot, α
st=Cst/Ctot
(Formula
1)
are set to be different values between a portion close to feeding ends in a screen and a portion away therefrom,a potential of a scanning electrode becomes a first potential level Vgon when the scanning electrode is selected and becomes substantially a second potential level Vgoff during a retention period in which the scanning electrode is not selected, a potential of a common electrode that is a connection destination of storage capacitance connected to pixel electrodes of a plurality of pixels belonging to the scanning electrode becomes a first potential level Vc(+) in a case where a polarity of a video signal is positive and a second potential level Vc(−
) in a case where the polarity of the video signal is negative, when the scamming electrode is selected, andin a case where a difference between the first potential level Vc(+) of the common electrode and a potential during a subsequent retention period is represented by Δ
Vc(+), and a difference between the second potential level Vc(−
) of the common electrode and a potential during a subsequent retention period is represented by Δ
Vc(−
),β
represented by
β
=α
gd+α
st(Δ
Vcc/Δ
Vgon)
(Formula
4)
(where Δ
Vgon=Vgon−
Vgoff, Δ
Vcc=[Δ
Vc(+)+Δ
Vc(−
)]/2
(Formula
5))
is set to be larger in the portion away from the feeding ends in the screen, compared with the portion close thereto. - View Dependent Claims (19, 20)
-
-
21. A display apparatus, comprising:
-
a plurality of pixel electrodes arranged in a matrix;
switching elements connected thereto;
scanning electrodes;
video signal electrodes;
common electrodes;
a counter electrode;
a display medium interposed between the pixel electrodes and the counter electrode;
storage capacitance formed between the pixel electrodes and the common electrodes;
a video signal driving circuit for applying two kinds of video signals having different polarities to video signal electrodes in accordance with a display period; and
a common electrode potential control circuit for applying a voltage signal to a plurality of common electrodes and a scanning signal driving circuit for applying a voltage signal to a plurality of scanning electrodes, the common electrode potential control circuit has output potential levels of at least two values, and the scanning signal driving circuit has output potential levels of at least two values, wherein, in a case where a scanning electrode-pixel electrode capacitance between the pixel electrodes and the scanning electrodes is represented by Cgd, a common electrode-pixel electrode capacitance between the pixel electrodes and the common electrodes is represented by Cst, and a total capacitance connected electrically to the pixel electrodes is represented by Ctot, α
gd and α
st represented by
α
gd=Cgd/Ctot, α
st=Cst/Ctot
(Formula
1)
are set to be different values between a portion close to feeding ends in a screen and a portion away therefrom,a potential of a scanning electrode becomes a first potential level Vgon when the scanning electrode is selected and becomes substantially a second potential level Vgoff during a retention period in which the scanning electrode is not selected, a potential of a common electrode that is a connection destination of storage capacitance connected to pixel electrodes of a plurality of pixels belonging to the scanning electrode becomes a first potential level Vc(+) in a case where a polarity of a video signal is positive and a second potential level Vc(−
) in a case where the polarity of the video signal is negative, when the scanning electrode is selected,in a case where a difference between the first potential level Vc(+) of the common electrode and a potential during a subsequent retention period is represented by Δ
Vc(+), and a difference between the second potential level Vc(−
) of the common electrode and a potential during a subsequent retention period is represented by Δ
Vc(−
),γ
represented by
γ
=α
stVcp/2
(Formula
2)
(where Vcp=Δ
Vc(+)−
Δ
Vc(−
)
(Formula
3))
is set to be smaller in the portion away from the feeding ends in the screen, compared with the portion close thereto, andβ
represented by
β
=α
gd+α
st(Δ
Vcc/Δ
Vgon)
(Formula
4)
(where Δ
Vgon=Vgon−
Vgoff, Δ
Vcc=[Δ
Vc(+)+Δ
Vc(−
)]/2
(Formula
5))
is set to be larger in the portion away from the feeding ends in the screen, compared with the portion close thereto.
-
-
22. A display element, comprising:
- a plurality of pixel electrodes arranged in a matrix;
switching elements connected thereto;
scanning electrodes;
video signal electrodes;
common electrodes;
a counter electrode;
a display medium interposed between the pixel electrodes and the counter electrode; and
storage capacitance formed between the pixel electrodes and the common electrodes,wherein, in a case where a scanning electrode-pixel electrode capacitance between the pixel electrodes and the scanning electrodes is represented by Cgd, a common electrode-pixel electrode capacitance between the pixel electrodes and the common electrodes is represented by Cst, and a total capacitance connected electrically to the pixel electrodes is represented by Ctot, α
gd and α
st represented by
α
gd=Cgd/Ctot, α
st=Cst/Ctot
(Formula
1)
are set to be different values between a portion close to feeding ends in a screen and a portion away therefrom, andan area of overlapping portions between the scanning electrodes and the pixel electrodes, and an area of overlapping portions between the common electrodes and the pixel electrodes are set to be larger in a screen center portion farthest from the feeding ends than in a screen end portion closest to the feeding ends, so that α
gd and α
st are both larger in the screen center portion farthest from the feeding ends than in the screen end portion closest to the feeding ends.
- a plurality of pixel electrodes arranged in a matrix;
Specification