Radiation imagery chemistry: process – composition – or product th – Radiation modifying product or process of making – Screen other than for cathode-ray tube
Reexamination Certificate
2002-10-23
2004-05-25
McPherson, John A. (Department: 1756)
Radiation imagery chemistry: process, composition, or product th
Radiation modifying product or process of making
Screen other than for cathode-ray tube
C349S106000
Reexamination Certificate
active
06740457
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates to a color filter substrate and a method for making the same, an electro-optical device and a method for making the same, and an electronic apparatus. The present invention relates particularly to a structure which can be suitably applied to a light shielding element of a display device.
2. Description of the Related Art
Generally, various electro-optical devices, such as liquid crystal displays, electroluminescent displays, and plasma displays, sometimes comprise color filters in which a plurality of colored layers in different colors are arrayed to achieve color display. In color filters, colored layers of, for example, three colors, i.e., red, green, and blue, are arrayed in a predetermined two-dimensional array pattern such as a stripe array, a diagonal mosaic array, or the like known in the art.
FIG. 10
is a schematic cross-sectional view illustrating the structure of a conventional transflective liquid crystal display
100
. The liquid crystal display
100
comprises: a reflecting substrate
110
of a half-transmissive structure including a first substrate
111
; a counter substrate
120
including a substrate
121
; a liquid crystal layer
130
held between the reflecting substrate
110
and the counter substrate
120
; a polarizer
141
and a quarter-wave plate
142
disposed on the outer face of the counter substrate
120
; a polarizer
143
and a quarter-wave plate
144
disposed on the outer face of the reflecting substrate
110
; and a backlight
150
disposed on the outer face of the polarizer
143
.
The reflecting substrate
110
comprises: a reflecting layer
112
formed on the first substrate
111
; a transparent insulating layer
113
formed on the reflecting layer
112
; electrodes
114
composed of a transparent conductor such as indium tin oxide (ITO); and an alignment film
115
.
The counter substrate
120
comprises: light shielding layers
122
formed on the substrate
121
; a red colored layer
123
R, a green colored layer
123
G, and a blue colored layer
123
B arranged in pixel regions Pr, Pg, and Pb, respectively, according to a predetermined pattern; a transparent protection layer
124
formed on the colored layers
123
R,
123
G, and
123
B; counter electrodes
125
made of a transparent conductor disposed on the protection layer
124
; and an alignment film
126
formed on the counter electrodes
125
.
The reflecting layer
112
of the liquid crystal display
100
has an aperture
112
a
formed in each of the pixel regions Pr, Pg, and Pb and allows light from the backlight
150
to pass through the apertures
112
a
so as to achieve transmissive display. Meanwhile, since external light entering from the observer side, i.e., the upper side in the drawing, is reflected at the portions of the reflecting layer
112
inside the pixel regions Pr, Pg, and Pb, reflective display is achieved. Thus, the liquid crystal display
100
is of a transflective type.
The light shielding layers
122
are formed on the substrate
121
in positions above the gaps between the pixel regions Pr and Pg, Pg and Pb, and Pb and Pr. Each of the light shielding layers
122
has a laminated structure of two or three layers in which, for example, a chromium thin film and a chromium oxide thin film are stacked so that the light shielding layers
122
hardly reflects external light and appear black when viewed from the observer side, i.e., the upper side in the drawing.
However, in the conventional liquid crystal display
100
, the light shielding layers
122
must have a laminated structure to prevent a decrease in the contrast due to reflection at the light shielding layers
122
when viewed from the observer side. Thus, the number of process steps increases, and so does the manufacturing cost, which is a problem.
Moreover, in the light shielding layers
122
, the thickness of a reflecting material, such as Cr, must be large enough to achieve a high light-shielding effect; thus, forming the light shielding layers
122
takes long time. This results in a decrease in production efficiency and an increase in manufacturing cost, which is a problem.
Furthermore, although the light shielding layers
122
appear black when observed from the observer side, i.e., from the substrate
121
side, the light shielding layers
122
are configured to reflect light when viewed from the opposite side, i.e., the first substrate
111
side. Thus, in order to avoid a decrease in contrast due to reflection of light at the light shielding layers
122
, a color filter comprising colored layers and a protection layer cannot be formed on the reflecting substrate
110
, i.e., the substrate at the side opposite to the observer side. Such a structure, which is opposite to the above-described structure, cannot be employed, which is a problem.
The present invention aims to overcome the above-described problems. An object of the present invention is to provide a color filter substrate, an electro-optical device, and methods for manufacturing the same that can prevent an increase in the number of the process steps and the manufacturing cost. Another object of the present invention is to provide a color filter substrate, an electro-optical device, and methods for manufacturing the same that can shorten the time required for forming the light shielding structure and increase the production efficiency. Yet another object of the present invention is to provide a color filter substrate, an electro-optical device, and methods for manufacturing the same that can operate without trouble even when a color filter is formed on the reflecting substrate, i.e., the substrate at the side opposite to the observer side, or when a substrate incorporating a color filter is used as the reflecting substrate, i.e., the substrate at the side opposite to the observer side.
SUMMARY OF THE INVENTION
To overcome the above-described problems, the present invention provides a color filter substrate comprising a substrate, a reflective light-shielding layer, and a plurality of colored layers of different colors, wherein the plurality of colored layers of different colors are stacked in a plan view at the reflective light-shielding layer.
According to this invention, a plurality of colored layers of different colors is stacked in a plan view at a reflective light-shielding layer. Thus, particularly when observed from the plurality of colored-layers side, degradation in display contrast due to the reflection of light can be prevented because light reflected at the reflective light-shielding layer can be efficiently absorbed by the plurality of colored layers of different colors. Even when observed from the reflective-light-shielding-layer side, degradation in contrast can also be prevented because the reflectance of the reflective light shielding layer is decreased. In such a case, a sufficient light-shielding effect can be obtained due to the presence of the plurality of colored layers even when the reflectance of the reflective light-shielding layer is decreased.
Since only stacking of the plurality of colored layers at the reflective light-shielding layer is necessary, no additional step is required, thereby preventing an increase in the manufacturing cost. Moreover, since the plurality of colored layers are stacked in a plan view at the reflective light-shielding layer, a sufficient light-shielding effect can be achieved without increasing the thickness of the reflective light-shielding layer, thereby reducing time required to form the reflective light-shielding layer, improving the productivity, and decreasing the cost. Furthermore, a decrease in contrast due to reflection of light can be prevented even when a color filter is formed on a reflecting substrate or a substrate at the side opposite to the observation side.
The reflective light-shielding layer is preferably composed of metal material to reduce the manufacturing cost and time. The metal material may be aluminum, silver, tantalum, nickel, chromium, or an alloy thereof.
In preparing a
Harness & Dickey & Pierce P.L.C.
McPherson John A.
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