Liquid crystal cells – elements and systems – Particular excitation of liquid crystal – Plasma excitation
Reexamination Certificate
1999-10-04
2002-06-25
Ton, Toan (Department: 2871)
Liquid crystal cells, elements and systems
Particular excitation of liquid crystal
Plasma excitation
C313S582000
Reexamination Certificate
active
06411345
ABSTRACT:
RELATED APPLICATION DATA
The present application claims priority to Japanese Application No. P10-282992 filed Oct. 5, 1998 which application is incorporated herein by reference to the extent permitted by law.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a plasma addressed liquid crystal display device comprised of an electro-optical display cell, having a layer of an electro-optical material, and a plasma cell, operating as a scanning switch, are layered together with a dielectric sheet in-between.
2. Description of the Related Art
Heretofore, a plasma addressed liquid crystal display device has been proposed, which is comprised of an electro-optical display cell and a plasma cell, layered together with a dielectric sheet in-between.
A plasma addressed liquid crystal display device
100
includes a flat panel structure comprised of an electro-optical display cell
101
, a plasma cell
102
and an interposed dielectric sheet
103
, layered together, as shown in
FIGS. 1 and 2
. The dielectric sheet
103
is constructed by, for example, a thin glass sheet. For driving the display cell
101
, the dielectric sheet
103
needs to be as thin as possible and is formed to a sheet thickness of, for example, 50 &mgr;m.
The display cell
101
is constructed using an upper glass substrate (front side substrate)
104
. On an inner major surface of the front side substrate
104
, there are plural data electrodes
105
of a transparent electrically conductive material, extending in the horizontal direction and which is layered side-by-side in the row direction (vertical direction). The front side substrate
104
is bonded to the dielectric sheet
103
with a pre-set gap by a spacer. In the gap between the front side substrate
104
and the dielectric sheet
103
is formed a liquid crystal layer
107
by charging a liquid crystal as an electro-optical material. The gap between the front side substrate
104
and the dielectric sheet
103
is of the order of, for example, 4 to 10 &mgr;m, and is kept uniformly over the entire display surface.
The plasma cell
102
is constructed using a lower transparent glass substrate (rear side substrate)
108
. On the inner major surface of the front side substrate
104
, plural anode electrodes
109
A and plural anode electrodes
109
K, constituting a plasma electrode, are alternately formed side-by-side in the column direction as a pre-set gap is maintained therebetween. At the mid portions of the upper surfaces of the anode electrodes
109
A and anode electrodes
109
K are formed barrier ribs
110
of a pre-set with for extending along the electrodes. The upper ends of the barrier ribs
110
are abutted against the lower sides of the dielectric sheet
103
to maintain a constant size of the gap between the rear side substrate
108
and the dielectric sheet
103
.
On the rim portions of the rear side substrate
108
is arranged a frit seal material
111
of, for example, a low-melting glass, for extending along the rim portions, for air-tightly bonding the rear side substrate
108
and the dielectric sheet
103
. In a gap between the rear side substrate
108
and the dielectric sheet
103
is sealed an ionizable gas.
In the gap between the rear side substrate
108
and the dielectric sheet
103
are arranged plural discharge channels
112
for extending side-by-side along the row direction. The discharge channels
112
are separated from one another by respective partitions
110
.
That is, the discharge channels
112
are formed at right angles to the data electrodes
105
, which operate as row driving units. The anode electrodes
109
A are connected in common and fed with the anode voltage, as will be explained subsequently, so that paired discharge channels
112
, disposed on either sides of the cathode electrodes
109
K, prove column driving units. At each intersection of the anode and cathode electrodes is defined a pixel
113
, as shown in FIG.
3
.
If, in the above structure, a pre-set voltage is applied across the anode electrode
109
A and the cathode electrode
109
K corresponding to the pre-set paired discharge channels
112
, the gas in the paired discharge channels
112
is selectively ionized to generate plasma discharge, the inside of which is maintained at an anode potential. If, in this state, the data voltage is sequentially applied to the data electrodes
105
, the data voltage is written via dielectric sheet
103
to the liquid crystal layer
107
of the plural pixels
113
arrayed in the row direction in register with the paired discharge channels
112
. On completion of the plasma discharge, the discharge channels
112
are at a floating potential, such that the data voltage written in the liquid crystal layer
107
of each pixel
113
is held by the operation of the dielectric sheet
103
until the next writing period, such as after one frame. In this case, the discharge channel
112
operates as a sampling switch, with the liquid crystal layer
107
of each pixel
113
and/or the dielectric sheet
103
operating as sampling capacitors.
Since the liquid crystal operates by the data voltage written in the liquid crystal layer
107
of each pixel
113
, display is on the pixel basis. By generating the plasma discharge for sequentially scanning in the column direction the paired discharge channels
112
for writing the data voltage in the liquid crystal layer
107
of plural pixels
113
arrayed in the row direction, it is possible to display a two-dimensional image.
FIG. 4
shows a circuit structure of the plasma addressed liquid crystal display device
100
. In
FIG. 4
, the reference numeral
121
is a liquid crystal driver to which video data is supplied. To this liquid crystal driver
121
is supplied video data. From the liquid crystal driver
121
, data voltages DS
1
to DS
m
of plural pixels, constituting a scanning line, are outputted simultaneously every horizontal period. Data voltages DS
1
to DS
m
of plural pixels constituting the respective lines are outputted from the liquid crystal driver
121
every horizontal period. These plural voltages DS
1
to DS
m
are routed via respective buffers
122
1
to
122
m
to the plural data electrodes
105
1
to
105
m
.
The operation of the liquid crystal driver
121
is controlled by a control circuit
123
, which is fed with horizontal synchronization signals HD and the vertical synchronization signals VD corresponding to video data. The operation of a anode driver
124
and a cathode driver
125
, as later explained, is also controlled by this control circuit
123
.
To the plural anode electrodes
109
A
1
to
109
A
n
, connected in common by the anode driver
124
, an anode voltage VA, as a reference voltage, is supplied. To the plural cathode electrodes
109
K
1
to l
09
K
n−1
, cathode voltages VK
1
to VK
n−1
, having pre-set potential differences from the anode potential, are supplied by the cathode driver
125
every horizontal period. In this manner, plasma discharge is sequentially produced in the paired discharge channels
112
associated with the cathode electrodes VK
1
to VK
n−1
, so that the paired discharge channels
112
for writing the data voltages DS
1
to DS
m
in the liquid crystal layer
107
of the plural pixels
113
arrayed in the row direction are sequentially scanned in the column direction.
The cathode voltage applied to te cathode electrode
109
K and the data voltage DS applied to the data electrode
105
are explained.
FIGS. 5A
to
5
D show the cathode voltages VK
a
to VK
a+3
applied to the cathode electrodes
109
K
a
to
109
K
a+3
, respectively.
FIG. 5E
shows the data voltage DS applied to the pre-set data electrode
105
. To the cathode electrodes
109
K
a
to
109
K
a+3
, cathode voltages VK
a
to VK
a+3
, lying at pre-set potential differences from the anode potential, are applied during each one horizontal period (1H) on the frame basis. This sequentially scans the discharge channels
112
, generating the plasma discharge, in the column direction (in the horizontal
Sekizawa Hidehiko
Tanaka Masanobu
Togawa Takahiro
Yano Tomoya
Sonnenschein Nath & Rosenthal
Ton Toan
LandOfFree
Plasma addressed liquid crystal display device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Plasma addressed liquid crystal display device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plasma addressed liquid crystal display device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2937180