Radiation imagery chemistry: process – composition – or product th – Radiation modifying product or process of making – Screen other than for cathode-ray tube
Reexamination Certificate
2002-10-02
2004-09-07
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, C313S584000
Reexamination Certificate
active
06787275
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a color filter and a manufacturing method therefor, and a display device and electronic equipment, and relates specifically to the colored sections of color filters.
BACKGROUND ART
In recent years, in electronic equipment such as notebook computers, mobile telephones and electronic organizers, display devices such as liquid crystal display devices and plasma discharge display devices have become widely used as devices for displaying information. Recently, display devices in which full color display is made possible by providing a color filter on one of the substrates have become mainstream.
A color filter is formed by arranging R (red), G (green) and B (blue) colored sections in an arrangement such as a stripe arrangement, a delta arrangement or a mosaic arrangement on the surface of a substrate made of glass or plastic or the like. There are several methods for manufacturing this color filter, which are classified into several groups according to the materials and manufacturing method used for the colored sections. But recently an inkjet method whereby a plurality of colored sections are formed on a substrate by discharging colored ink from the nozzle of an ink jet head has been proposed (see for example patent publications 1, 2 below).
1. Japanese Unexamined Patent Application, First Publication No. 2000-310706A
2. Japanese Unexamined Patent Application, First Publication No. Hei 11-248926A
Here, a method of manufacturing a color filter using a conventional ink jet method is described with reference to the drawings.
FIG. 47
to
FIG. 51
are cross-sectional views showing an example of the manufacturing steps for a color filter.
First, as shown in
FIG. 47
, a black matrix (light shielding layer)
901
made of metal Cr or the like is formed on a substrate
900
, and a resist layer
902
which covers the substrate
900
and the black matrix
901
is then formed. The black matrix
901
is formed for example, by the steps of forming a metal Cr film, forming a resist layer, performing exposure treatment, performing etching treatment, and removing the resist layer.
Next, as shown in
FIG. 48
, a portion of the resist layer
902
is removed by performing exposure treatment and etching treatment on the resist layer
902
to form concave sections
903
. The concave sections
903
are partitioned by the substrate
900
and bank sections
904
which represent the remaining sections of the resist layer
902
.
Next, as shown in
FIG. 49
, the R (red) colored sections
905
are formed in the concave sections
903
by discharging colored ink, which is the material which forms the colored sections, from an ink jet head which is not shown in the diagram into a portion of the concave sections
903
, and then drying this colored ink.
Next, as shown in
FIG. 50
, in the same manner as for the R (red) colored sections
905
, G (green) colored sections
906
and B (blue) colored sections
907
are sequentially formed in other concave sections
903
. Because the colored sections
905
,
906
and
907
are separated from other adjacent colored sections by the bank sections
904
, the colored sections do not mix with each to form color mixtures.
Finally, as shown in
FIG. 51
, an over coat layer
908
made of an acrylic resin or an epoxy resin or the like is formed over the colored sections, to obtain the color filter.
However, in the conventional color filter shown in
FIG. 51
, in order to prevent the colored sections
905
,
906
,
907
from mixing together, the height of the bank sections
904
must be set to approximately twice the thickness of the colored sections
905
,
906
,
907
, and consequently, a difference in level occurs between the bank sections
904
and the colored sections
905
, and the presence of this difference in level makes it difficult to ensure flatness of the over coat layer
908
. The over coat layer
908
eventually partitions the cell gap which supports the liquid crystal in the liquid crystal device, and consequently a reduction in the flatness of the over coat layer
908
can lead to unevenness in the spacing of the cell gap, which may adversely affect the contrast ratio or the operating voltage or the like of the liquid crystal device.
Accordingly, in order to ensure the flatness of the over coat layer
908
, it is possible to form the over coat layer
908
thickly and fill in the differences in level between the bank sections
904
and the colored sections
905
, but if the over coat layer
908
is thick, the overall thickness of the color filter increases, and consequently a problem occurs in that the light transmittance of the color filter is reduced, causing a reduction in the brightness of the liquid crystal device.
In addition, in conventional color filter manufacturing methods, a further problem arises in that in order to form the black matrix
901
and the bank sections
904
, the exposure treatment and the etching treatment must each be performed at least twice, and as a result the manufacturing steps tend to become complex.
DISCLOSURE OF THE INVENTION
The present invention takes the above factors into consideration, with an object of providing a color filter which is low cost, has excellent light transmittance, is thin and has excellent flatness.
Furthermore, another object of the present invention is to provide a color filter manufacturing method in which the manufacturing steps can be simplified.
In addition, yet another object of the present invention is to provide a display device comprising an aforementioned color filter, in which there is no irregularity in the contrast ratio and operating voltage, and which has high contrast and good visibility, and to also provide electronic equipment incorporating this display device.
In order to achieve these objects, the present invention employs the following construction.
A color filter of the present invention is a color filter produced by forming a plurality of colored sections on a substrate, wherein a plurality of concave sections are formed in one surface of the substrate, an ink repellant layer is formed between adjacent concave sections, formation sections are formed by the concave sections and the ink repellant layer, and the colored sections are formed in each formation section.
According to this color filter, the colored sections are formed in formation sections partitioned by a thin walled section and the ink repellant layer, meaning that at least a portion of the colored section is embedded in the substrate, enabling the thickness of the colored section regions to be reduced, and consequently it is possible to improve the light transmittance of the color filter.
Furthermore, because at least a portion of the colored section is embedded in the substrate, differences in level between the colored sections and the ink repellant layer can be minimized, and consequently even if the over coat layer which protects the colored sections and the ink repellant layer is formed more thinly than in conventional methods, the flatness of the over coat layer can still be ensured, and the light transmittance of the color filter can be improved by reducing the thickness of the filter.
In addition, because an ink repellant layer which has colored ink repellant properties is formed around the thin walled section, when colored ink is discharged to form the colored sections, there is no danger of the discharged colored ink spreading outside the formation sections, and no danger of adjacent colored sections contacting each other and resulting in color mixing.
Furthermore, a color filter of a mode the present invention is the color filters as disclosed above, wherein at least the upper surface of the ink repellant layer has ink repellant properties, and the formation sections are formed by partitioning by the concave sections and the wall surfaces of the ink repellant layer which are continuations of the wall surfaces of the concave sections.
According to this color filter, because the upper surface of the ink repellant layer has ink repellant properties, even if the colore
McPherson John A.
Seiko Epson Corporation
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