U.S. patent application number 11/979212 was filed with the patent office on 2008-06-05 for color display substrate, color filter substrate, color luminescent substrate, manufacturing method of color display substrate, electro-optical apparatus, electronic device, film-forming method, film-forming apparatus, and display motherboard.
This patent application is currently assigned to Seiko Epson Corporation. Invention is credited to Hisashi Aruga, Satoru Katagami, Hiroshi Kiguchi, Yoshiaki Yamada.
Application Number | 20080131603 11/979212 |
Document ID | / |
Family ID | 26614621 |
Filed Date | 2008-06-05 |
United States Patent
Application |
20080131603 |
Kind Code |
A1 |
Aruga; Hisashi ; et
al. |
June 5, 2008 |
Color display substrate, color filter substrate, color luminescent
substrate, manufacturing method of color display substrate,
electro-optical apparatus, electronic device, film-forming method,
film-forming apparatus, and display motherboard
Abstract
The invention provides a color display substrate having plural
color display elements arranged in a matrix pattern, and a
manufacturing method to efficiently obtain a color filter substrate
and color luminescent substrate, for example. A manufacturing
method of a color display substrate includes the step of forming
plural color dots by selectively ejecting liquid droplets from
nozzles in accordance with input data. The plural color dots
constitute plural pixels, which constitute plural color filter
elements arranged in a matrix pattern. The plural color dots have a
first dot pitch in a direction perpendicular to a first base line.
Each of the plural color dots is formed to lie at a distance of at
least substantially an integral multiple of the first dot pitch
from the first base line.
Inventors: |
Aruga; Hisashi;
(Fujimi-machi, JP) ; Katagami; Satoru; (Hara-mura,
JP) ; Yamada; Yoshiaki; (Shimosuwa-machi, JP)
; Kiguchi; Hiroshi; (Suwa-shi, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 320850
ALEXANDRIA
VA
22320-4850
US
|
Assignee: |
Seiko Epson Corporation
Tokyo
JP
|
Family ID: |
26614621 |
Appl. No.: |
11/979212 |
Filed: |
October 31, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10131472 |
Apr 25, 2002 |
|
|
|
11979212 |
|
|
|
|
Current U.S.
Class: |
427/256 ;
118/300 |
Current CPC
Class: |
H01L 27/3211 20130101;
H01L 27/3246 20130101; G02F 1/133514 20130101; H01L 27/322
20130101; H01L 51/5284 20130101; G02F 1/133516 20130101 |
Class at
Publication: |
427/256 ;
118/300 |
International
Class: |
B05D 5/00 20060101
B05D005/00; B05C 5/00 20060101 B05C005/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 2, 2001 |
JP |
2001-134875 |
Mar 27, 2002 |
JP |
2002-087601 |
Claims
1. A method for forming a film, comprising: arranging a plurality
of dot elements within a colored layer to have a first dot pitch in
a direction perpendicular to a base line; and locating each of the
plurality of dot elements at a distance of at least substantially
an integral multiple of the first dot pitch from the base line; and
arranging the plurality of dot elements within the colored layer to
have a second dot pitch in a direction of the base line.
2. An apparatus for forming a film, comprising: means for arranging
a plurality of dot elements within a colored layer to have a first
dot pitch in a direction perpendicular to a base line, wherein each
of the plurality of dot elements is located at a distance of at
least substantially an integral multiple of the dot pitch from the
base line; and means for arranging the plurality of dot elements
within the colored layer to have a second dot pitch in a direction
of the base line.
3. The method of claim 1, wherein arranging the plurality of dot
elements further comprises: forming the plurality of dot elements
by selectively ejecting liquid droplets from at least one nozzle in
accordance with input data.
4. The apparatus of claim 2, wherein the means for arranging
comprises: a nozzle head with a plurality of nozzles arranged in
the head to eject liquid droplets, the liquid droplets being
selectively ejected from the nozzles so as to form a plurality of
dot elements by scanning the head, the nozzles having an effective
nozzle-array length in the direction of the base line, and the
effective nozzle-array length being substantially an integral
multiple greater than one of the predetermined dot pitch.
5. The method for forming a film according to claim 1, wherein the
colored layer does not include a liquid crystal material.
6. The apparatus for forming a film according to claim 2, wherein
the colored layer does not include a liquid crystal material.
Description
[0001] This is a Division of application Ser. No. 10/131,472 filed
Apr. 25, 2002. The disclosure of the prior application is hereby
incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a color display substrate,
a color filter substrate, a color luminescent substrate, a
manufacturing method of the color display substrate, an
electro-optical apparatus, an electronic device, a film-forming
method, a film-forming apparatus, and a display motherboard.
[0004] 2. Description of Related Art
[0005] Recently, along with advancements in personal computers,
especially in portable personal computers and portable information
devices, the demand for liquid crystal color displays has strongly
increased. Accordingly, an urgent need exists to establish a method
of providing an excellent display at a fair price. In order to
provide environmental protection, conversion into, and enhancement
of, methods to reduce environmental loading are also demanded.
[0006] The following is a related art method for manufacturing a
color filter.
[0007] In the method, first, a chrome thin film is patterned by
photolithography and etching so as to form black matrixes as light
shielding material. Then, after coating clearances between the
black matrixes with red, green, and blue photoresists, a spin
coating method is performed for each color, and patterning is
performed by photolithography. Thereby, color matrixes, in which
red, green, and blue colored layers (color dots) are arranged to be
adjacent to one another, are formed. In this manufacturing method,
the photolithography process has to be repeated for each color, and
since an unnecessary portion is removed for patterning each color,
losses in a photoresist are produced, resulting in a color filter
with high cost and high environmental loading.
[0008] Thus, as a method for addressing or solving the problem of
such a manufacturing method, a method employing an inkjet technique
is proposed in Japanese Unexamined Patent Application Publication
No. 59-75205, for example. According to this method, after
partitions are created on a transparent substrate in matrix
arrangements so as to define a color-dot-forming region with a
material with low wettability to ink, the color dot is formed by
coating within the partition with a non-photosensitive color
material by the inkjet technique. In this method, the complexity of
the photolithography process can be eased, and also losses in color
material can be reduced. Various other related art manufacturing
methods employing a process of coating with the non-photosensitive
color material by the inkjet technique have also been proposed.
SUMMARY OF THE INVENTION
[0009] The present invention provides a manufacturing method
capable of efficiently obtaining a color display substrate having a
plurality of color display elements arranged in matrix
arrangements, such as a color filter substrate and
color-luminescent substrate.
[0010] The present invention also provides a color display
substrate manufactured by the manufacturing method mentioned above,
such as a color filter substrate and color luminescent
substrate.
[0011] The present invention further provides an electro-optical
apparatus and electronic device having a color indicator obtained
from the color display substrate mentioned above.
[0012] A color display substrate according to the present invention
includes a plurality of color display elements arranged in a matrix
pattern,
[0013] a plurality of pixels that constitute each of the plurality
of color display elements, and
[0014] a plurality of color dots that constitute each of the
plurality of pixels.
[0015] The plurality of color dots have a first dot pitch in a
direction perpendicular to a first base line.
[0016] Each of the plurality of color dots is located at a distance
of at least substantially an integral multiple of the first dot
pitch from the first base line.
[0017] The color display substrate can be efficiently obtained by a
manufacturing method, which will be described below.
[0018] The color display substrate according to the present
invention may have various other features as follows.
[0019] (A) The color dots of the color display elements may further
be located at a distance of substantially an integral multiple of a
second dot pitch in a direction perpendicular to a second base line
from the second base line perpendicular to the first base line.
[0020] (B) The spacing between the color display elements may be
substantially an integral multiple of the second dot pitch in the
direction of the first base line while being substantially an
integral multiple of the first dot pitch in the direction of the
second base line. By such a setting, the color element pitch can be
prescribed as substantially an integral multiple of the first and
second dot pitches. That is, from viewpoint of the color element
pitch, the arrangement pitch of the color elements is substantially
an integral multiple of the second dot pitch in the direction of
the first base line while being substantially an integral multiple
of the first dot pitch in the direction of the second base
line.
[0021] (C) The arrangement of the pixels of the color display
elements may be any one of a stripe type, a mosaic type, a delta
type, and a square type.
[0022] (D) The color dots may be formed of liquid droplets ejected
from nozzles, and the color dots may include a color display layer
and a bank layer to lay out a colored layer. The bank layer serves
as a partition to bank up the liquid droplet ejected from the
nozzle.
[0023] A color display substrate according to the present invention
is applicable to various display substrates capable of color
displaying with the three primary colors of red, green, and blue. A
color filter substrate and a color luminescent substrate are
examples of typical display substrates.
[0024] For example, the color filter substrate according to the
present invention includes a plurality of color filter elements
arranged in a matrix pattern,
[0025] a plurality of pixels that constitute each of the plurality
of color filter elements, and
[0026] a plurality of color dots that constitute each of the
plurality of pixels.
[0027] The plurality of color dots have a first dot pitch in a
direction perpendicular to a first base line.
[0028] Each of the plurality of color dots is located at a distance
of at least substantially an integral multiple of the first dot
pitch from the first base line.
[0029] A color luminescent substrate according to the present
invention includes a plurality of color luminescent elements
arranged in a matrix pattern,
[0030] a plurality of pixels that constitute each of the plurality
of color luminescent elements, and
[0031] a plurality of color dots that constitute each of the
plurality of pixels.
[0032] The plurality of color dots have a first dot pitch in a
direction perpendicular to a first base line.
[0033] Each of the plurality of color dots is located at a distance
of at least substantially an integral multiple of the first dot
pitch from the first base line.
[0034] A method for manufacturing a color display substrate
according to the present invention includes the step of forming a
plurality of color dots by selectively ejecting liquid droplets
from nozzles in accordance with input data.
[0035] The plurality of color dots constitute a plurality of
pixels.
[0036] The plurality of pixels constitute a plurality of color
display elements.
[0037] The plurality of color display elements are arranged in a
matrix pattern.
[0038] The plurality of color dots have a first dot pitch in a
direction perpendicular to a first base line.
[0039] Each of the plurality of color dots is located at a distance
of at least substantially an integral multiple of the first dot
pitch from the first base line.
[0040] According to the manufacturing method, each color-dot
forming-region constituting the color display element is located at
a distance of at least substantially an integral multiple of the
first dot pitch in a direction perpendicular to a first base line
from the first base line, so that positional data of the color-dot
forming-region can be prescribed by the first dot pitch,
facilitating the design.
[0041] An inkset system may be used as a method to selectively
eject the liquid droplets from nozzles, for example.
[0042] The manufacturing method according to the present invention
may have various other features as follows.
[0043] (A) The region where the color dots are formed of the color
display element may be located at a distance of substantially an
integral multiple of a second dot pitch in a direction
perpendicular to a second base line from the second base line
perpendicular to the first base line. By such a setting, not only
from the first base line but also from the second base line,
positional data of the color-dot forming-region can be prescribed
by the second dot pitch, facilitating the design.
[0044] (B) The spacing between the color display elements may be
substantially an integral multiple of the second dot pitch in the
direction of the first base line while being substantially an
integral multiple of the first dot pitch in the direction of the
second base line. By such setting, the pitch of the color display
elements can be prescribed by the first and second dot pitches. The
arrangement of the color display elements can be set to be
substantially an integral multiple of the second dot pitch in the
direction of the first base line while being substantially an
integral multiple of the first dot pitch in the direction of the
second base line.
[0045] (C) The method further includes the steps of forming a bank
layer to lay out a color display layer of the color dots, and
supplying liquid droplets to a region laid out by the bank layer.
The bank layer serves as a partition to bank up the liquid droplets
ejected from the nozzles.
[0046] (D) The head for the ejecting liquid droplets has a nozzle
array having a plurality of nozzles, which are arranged linearly so
as to have a predetermined pitch in the direction of the first base
line, and the nozzle array has an effective nozzle-array length
including a plurality of regions where the color-display elements
are formed. In accordance with the head for the ejecting liquid
droplets having such an effective nozzle-array length, by one round
of scanning, plural lines of the color display element can be
formed.
[0047] Furthermore, in the nozzle array, the effective nozzle-array
length in the direction of the first base line may be substantially
an integral multiple of the second element pitch of the color
display elements.
[0048] (E) The color display element may include the color filter
element or a color luminescent element.
[0049] An electro-optical apparatus according to the present
invention includes a color indicator obtained from the color
display substrate according to the present invention.
[0050] An electro-optical apparatus according to the present
invention includes a color filter obtained from the color filter
substrate according to the present invention, an opposing substrate
arranged at a predetermined distance from the color filter, and an
electro-optical material layer placed between the color filter and
the opposing substrate. The electro-optical material layer may be a
liquid-crystal material layer.
[0051] An electro-optical apparatus includes a color illuminator
obtained from a color luminescent substrate according to the
present invention. The luminescent layer of the color dot may
include an electroluminescence material.
[0052] An electronic device includes an electro-optical apparatus
according to present invention.
[0053] A display motherboard according to the present invention
includes a plurality of units, each constituting the display,
and
[0054] a plurality of dot elements arranged in line.
[0055] The plurality of dot elements are arranged within each of
the units in a predetermined direction at a first dot pitch, and
one of the plurality of dot elements included in each one of the
units and one of the plurality of dot elements included in the
other of the units are arranged at a distance of substantially an
integral multiple of the first dot pitch in the predetermined
direction.
[0056] A method for forming a film according to the present
invention includes the step of forming a plurality of dot elements
by selectively ejecting liquid droplets from nozzles.
[0057] The plurality of dot elements have a dot pitch in a
direction perpendicular to a base line.
[0058] Each of the plurality of dot elements is located at a
distance of at least substantially an integral multiple of the dot
pitch from the base line.
[0059] The film-forming apparatus may include a scannable head,
and
[0060] a plurality of nozzles arranged in the head to eject liquid
droplets.
[0061] The liquid droplets are selectively ejected from the nozzles
so as to form a plurality of dot elements by scanning the head.
[0062] The plurality of dot elements are arranged in the direction
of a base line while having a predetermined dot pitch in the
direction of the base line.
[0063] The nozzles have an effective nozzle-array length in the
direction of the base line, and the effective nozzle-array length
is substantially an integral multiple of the predetermined dot
pitch.
[0064] An inkjet head may be used as the scannable head, for
example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0065] FIG. 1 is a schematic perspective view of a color filter
substrate according to a first embodiment of the present
invention;
[0066] FIG. 2 is a plan view of a color filter element constituting
the color filter substrate shown in FIG. 1;
[0067] FIG. 3 is a schematic partial sectional view taken along
plane A-A of FIG. 2;
[0068] FIGS. 4(A) to (D) are partial sectional views schematically
showing manufacturing steps of the color filter substrate shown in
FIGS. 1 to 3;
[0069] FIGS. 5(A) to (D) are partial sectional views schematically
showing manufacturing steps of the color filter substrate shown in
FIGS. 1 to 3;
[0070] FIG. 6 is a plan view schematically illustrating a method
for manufacturing the color filter substrate according to the first
embodiment;
[0071] FIG. 7 is a plan view illustrating the manufacturing method
of the color filter substrate according to the first embodiment
having color filter elements with delta-type arrangement;
[0072] FIG. 8 is a schematic perspective view of a color
luminescent substrate according to a second embodiment of the
present invention;
[0073] FIG. 9 is a plan view of a color luminescent element
constituting the color luminescent substrate shown in FIG. 8;
[0074] FIGS. 10(A) to (D) are partial sectional views schematically
showing manufacturing steps of the color luminescent substrate
shown in FIGS. 8 and 9;
[0075] FIG. 11 is a plan view schematically illustrating a method
for manufacturing the color luminescent substrate according to the
second embodiment;
[0076] FIG. 12 is schematic illustrating an effective nozzle-array
length;
[0077] FIG. 13 is a sectional view schematically showing a liquid
crystal display as an example of an electro-optical apparatus
according to a third embodiment;
[0078] FIG. 14 is a perspective view of a digital still camera as
an example of an electronic device according to the present
invention;
[0079] FIGS. 15(A) to (C) show applicable examples of electronic
devices according to the present invention, where: FIG. 15(A) shows
a portable telephone; FIG. 15(B) shows a wrist watch; and FIG.
15(C) shows a portable information instrument, such as a portable
computer;
[0080] FIGS. 16(a) to (c) show modifications of the color filter
substrate according to the first embodiment, where: FIG. 16(a) is a
plan view of the color filter elements; FIG. 16(b) is a sectional
view taken along plane D-D of FIG. 16(a); and FIG. 16(c) is a
sectional view taken along plane E-E of FIG. 16(a);
[0081] FIG. 17 is a sectional view schematically showing an EL
display as an example of the electro-optical apparatus according to
the third embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
First Embodiment
[0082] FIG. 1 is a perspective view schematically showing a color
filter substrate as an example of a color display substrate
(display motherboard) applied in the present invention; FIG. 2 is a
plan view of a significant part of a color filter element (unit
constituting the display) forming the color filter substrate; and
FIG. 3 is a sectional view taken along plane A-A of FIG. 2.
[0083] (Overview of Color Filter Substrate)
[0084] First, an overview of a color filter substrate 1000 will be
described. The color filter substrate 1000 is of a
light-transmission type and includes a transparent substrate 10
made of glass or plastic, and plural color filter elements 100
formed on the substrate 10 in matrix arrangement. Plural color
filters can be obtained by cutting the color filter substrate 1000
at predetermined positions afterward.
[0085] The color filter element 100 according to an embodiment, as
shown in FIGS. 2 and 3, includes a transparent substrate 10, a
light-shielding region 20, which does not allow light (visible
light) to be substantially transmitted, and a light-transmissive
transmission region 30. The light-shielding region 20 includes a
light-shielding layer 22 and a bank layer 24 formed on the
light-shielding layer 22. The transmission region 30 is a region
defined by the light-shielding region 20 and includes a colored
layer 32 formed on the substrate 10.
[0086] According to the embodiment, as shown in FIG. 2, the length
of one dot pitch of the colored layer 32 and the light-shielding
region 20 with a predetermined width surrounding the colored layer
32 is prescribed to as one color dot (dot element) 100a. In the
description below, the dot pitch of the color dots 100a forming the
color filter element 100 in the X direction is referred to as a
first dot pitch Px, while the dot pitch in the Y direction is
referred to as a second dot pitch Py. In addition, the dot pitch,
as shown in FIG. 2, is referred to as the center distance between
color dots adjacent to each other.
[0087] Also, in the color filter substrate 1000, as shown in FIG.
1, the element pitch of the color filter elements 100 in the X
direction is referred to as a first element pitch PEx, while the
element pitch in the Y direction is referred to as a second element
pitch PEy. In addition, according to the embodiment, as shown in
FIG. 1, the element pitch means the distance between the sides of
adjacent color filter elements. The element pitch, of course, is
the same as the center distance between adjacent color filter
elements, so that it may also be defined as the center
distance.
[0088] The light-shielding layer 22 forming the light-shielding
region 20 is formed on the substrate 10 in a predetermined pattern.
The material of the light-shielding layer 22 is not specifically
limited to a metal or resin, as long as it is sufficiently
lightproof and functions as a black matrix. In regard to sufficient
and uniform lightproof that is gained for thin film-thickness, a
metal is preferable as the material of the light-shielding layer
22. The metal for use as the light-shielding layer 22 is not
specifically limited so as to be selected in consideration of
efficiency of the entire process including film forming and
photo-etching. As such a metal, one used in electronic device
processing, such as chrome, nickel, and aluminum, may be preferably
used, for example.
[0089] The bank layer 24 is formed on the light-shielding layer 22
so as to have a predetermined pattern. The bank layer 24 defines
regions to be formed by colored layers, and functions as a barrier
to prevent adjacent colored layers from being mixed with each other
(color mixture). Therefore, the film thickness of the bank layer 24
(the height h (see FIG. 3)) is established regarding the
relationship to the height of an ink layer so that an ink
composition (referred to as ink below) as a color material poured
during forming the colored layer does not overflow. From this point
of view, the range of the film thickness of the bank layer 24 may
preferably be 1 to 5 .mu.m.
[0090] The bank layer 24 is formed of a resin layer for which
photolithography can be performed. Such a photosensitive resin does
not necessarily need to have excellent water repellency with a
large contact angle with water or to have lightproof, enabling to
have wide selection. The photosensitive resin composition used as a
resin for the bank layer 24 may include an urethane resin, acrylic
resin, novolac resin, cardo resin, polyimide resin,
polyhydroxystyrene, and polyvinyl alcohol, for example.
[0091] The colored layer 32 includes plural colored layers 32 (R),
32 (G), and 32 (B), each for red, green, and blue, which constitute
the three primary colors. These colored layers 32 are arranged
according to a predetermined arrangement pattern, such as striped
arrangement, delta arrangement, mosaic arrangement, and square
arrangement, and one pixel is constituted of continuous colored
layers with three respective colors.
[0092] Features of the color filter substrate 1000 and the color
filter element 100 according to the embodiment will be described
below.
[0093] (Manufacturing Method of Color Filter Substrate)
[0094] Referring now to FIGS. 4(A)-5(D), an overview of a
manufacturing method of the color filter will be described. FIGS.
4(A)-5(D) include sectional views of the layer structures in each
step taken along plane B-B of FIG. 2.
[0095] (1) Light-Shielding Layer Forming
[0096] First, as shown in FIG. 4(A), a metallic layer 220 is
deposited on the transparent substrate 10 to have a film-thickness
of 0.1 to 0.5 .mu.m by dry plating, such as sputtering, vapor
deposition, and chemical deposition. As mentioned above, various
metals, such as chrome, nickel, and aluminum, may be used as a
material of the metallic layer 220. Then, on the surface of the
metallic layer 220, a resist layer R1 having a predetermined
pattern is formed by photolithography. Thereafter, patterning of
the metallic layer 220 is performed using the resist layer R1 as a
mask. In such a manner, as shown in FIG. 4(B), the light-shielding
layer 22 having a predetermined matrix pattern is formed on the
substrate 10.
[0097] (2) Bank Layer Forming
[0098] Then, as shown in FIG. 4(C), a resin layer 240 is formed on
the substrate 10 having the light-shielding layer 22 formed
thereon. The resin layer 240 is formed of a negative-type or
positive-type resist. The resin layer 240 is made of a
photo-curable type (negative type) photosensitive resin, such as an
urethane resin and acrylic resin. Then, the resin layer 240 is
patterned by exposure using a photo-mask M1 and by further
development. The bank layer 24, as shown in FIG. 4(D), is thereby
formed so as to form the light-shielding region 20. The
configuration of the light-shielding region 20 has been already
described so that the description is omitted. In this step,
colored-layer forming regions 330 defined by the light-shielding
region 20 are formed in a predetermined matrix pattern.
[0099] Next, prior to the next colored-layer forming step, surface
treatment of the substrate surface is performed when necessary.
Ultra-violet radiation, plasma radiation, laser beam radiation, and
the like may be utilized as such surface treatment. By such surface
treatment, contaminant adhering on an exposed surface 10a of the
substrate 10 is removed so as to reduce a contact angle of the
exposed surface 10a with water, enhancing ink wettability. More
specifically, it is preferable that the difference of the contact
angle with water between the exposed surface 10a of the substrate
10 and the surface of the bank layer 24 be 15.degree. or more. By
controlling the contact angle with water of the exposed surface 10a
of the substrate 10 and the surface of the bank layer 24 in such a
manner, ink can be applied on the exposed surface 10a of the
colored-layer forming region 330 in an excellent close-contact
state therewith, while being prevented from overflowing across the
bank layer 24 due to the water repellency of the bank layer 24. A
gas plasma method, ultra-violet radiation, and surface-active agent
coating may be adopted as a surface-treatment method.
[0100] (3) Colored Layer Forming
[0101] First, as shown in FIG. 5(A), ink is applied on the
colored-layer forming region 330 laid out by the light-shielding
layer 22 and the bank layer 24 so as to form an ink layer 320.
According to the embodiment, as an ink-applying method, an inkjet
method using a printing head is applied, which is used in an inkjet
printing system. As a method to form the ink layer with a high
degree of accuracy on the colored-layer forming region 330 having a
very small area, e.g., 50 .mu.m square, the inkjet printing system
is optimum, in which ejected ink-droplets are pulverized and
moreover, the number of ejected ink-droplets can be controlled.
[0102] In order to apply the pulverized ink droplet at a target
position (the exposed surface 10a of the substrate 10) with a high
degree of accuracy, first, the ink-droplet in size is controlled in
accordance with the size of the exposed surface 10a of the
colored-layer forming region 330. It is preferable to control the
size of the ink droplet, for example, to be 6 to 30 picoliter for
the colored-layer forming region 330 with an area of 50 .mu.m
square. More preferably, the size of the ink-droplet may be 12 to
20 picoliter in consideration of throughput. When the ink-droplet
is ejected from the inkjet printing head so as to accurately arrive
the target, it is preferable that the ink-droplet be controlled to
take a flight straight without being split.
[0103] According to the embodiment, the colored layer 32 is
sequentially formed with respect to each color of red, green, and
blue. The order of forming the colored layer 32 is not specifically
limited. In an example shown in FIG. 5(B), first, the red colored
layer 32(R) is formed; then, as shown in FIG. 5(C), one of the
green colored layer 32(G) and the blue colored layer 32(B) is
formed; and the remaining colored layer is finally formed. In
addition, when selecting the color heads or plural heads of the
inkjet printing system, the colored layers of red, green, and blue
can be simultaneously formed.
[0104] (4) Overcoat Layer Forming
[0105] Then, as shown in FIG. 5(C), after forming the colored layer
32, an overcoat layer 40 may be formed in order to obtain a smooth
surface thereon according to demand. Furthermore, as shown in FIG.
5(D), when necessary, a common electrode 50 is formed on the
surface of the overcoat layer 40 so as to finish the color filter
substrate 1000 having the color filter elements 100 arranged
thereon in a matrix pattern. The overcoat layer 40 and the common
electrode 50 may be provided according to the structure of an
electro-optical apparatus, to which the color filter is applied.
Thereafter, plural color filters are produced by cutting the color
filter substrate 1000 at predetermined positions.
[0106] (Features of Manufacturing Method)
[0107] FIG. 6 is a plan view illustrating the manufacturing method
according to the present invention and showing steps corresponding
to FIGS. 5(A) and 5(B). In FIG. 6, to simplify the drawing, color
dots 100a and color-dot forming regions 100b are shown. Also, in
FIG. 6, an example of forming stripe-type pixels is shown.
[0108] In FIG. 6, a first base line BL1 and second base line BL2
are established along the y direction and x direction,
respectively.
[0109] According to the embodiment, an inkjet head 1 for use in the
inkjet printing is moved relative to the substrate 10 in the x
direction so as to supply ink to the color-dot forming regions
100b, specifically to the colored-layer forming regions 330 (see
FIGS. 5(A) and (B)), completing the color dots 100a.
[0110] The inkjet head 1 has a nozzle array having plural nozzles
1a arranged linearly. In the nozzle array of the inkjet head 1, the
nozzles are arranged at a predetermined pitch in the direction of
the first base line BL1 (the same pitch as the second dot pitch Py,
in this example). Also, the nozzle array of the inkjet head 1 is
set to have plural rows (two rows, in this example) of the forming
regions of the color filter elements 100 in the direction of the
first base line BL1. In this example, since the pitch of nozzles 1a
is set to be the same as the second dot pitch Py, the nozzle array
length of the inkjet head 1 is substantially the same as an
effective nozzle array length.
[0111] "The effective nozzle array length", as shown in FIG. 12,
denotes a length Lno of the nozzle array for the first base line
BL1 when the inkjet head 1 is inclined by an angle q relative to
the first base line BL1. When the pitch of the nozzles 1a is not in
conformity with the second dot pitch Py, by inclining the inkjet
head 1 relative to the first base line BL1, a desired nozzle pitch
can be established. A symbol "LN" denotes the nozzle array length
of the inkjet head 1.
[0112] The base lines BL1 and BL2, the color filter element 100,
the color dot 100a, and the color-dot-forming region 100b satisfy
the following conditions (a) to (c).
[0113] (a) Each color-dot forming region 100b for the color filter
element 100 is established to lie at a distance (NPx, N is an
integer) of at least substantially an integral multiple of the
first dot pitch Px of the x direction from the first base line BL1
of the y direction. Furthermore, each color-dot forming region 100b
for the color filter element 100 is established to lie at a
distance (N'Py, N' is an integer) of substantially an integral
multiple of the second dot pitch Py of the y direction from the
second base line BL2 of the x direction.
[0114] (b) The spacing between the color filter elements 100 is
established as follows. A spacing Lx1 in the direction of the
second base line BL2 is set to be an integral multiple (nPx, n is
an integer except zero) of the first dot pitch Px. A spacing Ly1 in
the direction of the first base line BL1 is set to be an integral
multiple (n'Py, n' is an integer except zero) of the second dot
pitch Py.
[0115] That is, a first element pitch PEx in the direction of the
second base line BL2 is established to be an integral multiple of
the first dot pitch Px, while a second element pitch PEy in the
direction of the first base line BL1 is established to be an
integral multiple of the second dot pitch Py.
[0116] (c) A spacing Lx2 from the first base line BL1 to the first
line of the color filter elements 100 is set to be an integral
multiple (mPx, m is an integer) of the first dot pitch Px. A
spacing Ly1 from the second base line BL2 to the first row of the
color filter elements 100 is set to be an integral multiple (m'Py,
m' is an integer) of the second dot pitch Py.
[0117] When the conditions (b) and (c) are satisfied, the condition
(a) is satisfied. Therefore, according to the embodiment, in order
to form the color dots 100a by the inkjet system using the inkjet
head 1, ink-ejecting positions are established so as to satisfy the
condition (a), or the condition (b) plus the condition (c).
[0118] On the basis of the positional information of the base lines
BL1 and BL2 and the information required to form the colored layer,
ink is ejected at a predetermined position so as to form the color
dot 100a. The information required to form the color dot 100a is
appropriately selected based on the operating method of the inkjet
head, or the like, and it includes the information to specify the
position of the color-dot-forming region, the information to
specify the color of the colored layer, and the information to
specify the ejection timing to the color-dot-forming region, for
example.
[0119] In addition, in the example shown in FIG. 6, as a positional
reference of the color dot 100a or the color-dot forming region
100b, sides of each color dot 100a or color-dot forming region 100b
toward the base lines BL1 and BL2 are adopted. For such a
positional reference, the center of each color dot or
color-dot-forming region or other positions may, of course, be
adopted.
[0120] Next, referring to FIG. 6, the method of forming the color
dot 100a will be more specifically described. FIG. 6 shows a state
that the inkjet head 1 has been moved until the first line of the
color-dot forming region in the second-line color filter element.
Black circles denote regions in which ink is ejected with the
nozzles 1a of the inkjet head 1, while white circles denote regions
in which ink is not ejected with the nozzles 1a of the inkjet head
1.
[0121] In this example, first, the inkjet head 1 is moved in the x
direction relative to the substrate 10, so that, based on the
above-mentioned information required to form the color dot, the ink
of a first color (red (R) in this example) is ejected so as to form
the red color dots 100a. At this time, in the color-dot-forming
regions 100b to form colors other than red and in regions having no
color filter element 100 formed therein, ink is not ejected. During
one round movement of the inkjet head 1 in the x direction, the
first-color color dots in the first and the second row in the y
direction are formed.
[0122] Then, the inkjet head 1 is moved relative to the substrate
10 in the y direction so as to form the first-color color dots of
the third and the fourth row. Afterward, the first-color color dots
are similarly formed every two rows.
[0123] Next, using the inkjet head 1 with different colors, the
color dots 100a of the second-color (blue or green) and the
third-color (remained color) are formed in the same way as in the
first-color. In such a manner, the color dots 100a of the three
primary colors are formed at predetermined positions so as to
obtain the color filter substrate 1000 having plural color filter
elements 100 arranged in a matrix pattern.
[0124] According to the manufacturing method of the embodiment,
each color dot 100a is established to lie at distances of an
integral multiple of the first dot pitch and the second dot pitch
from the first base line BL1 and the second base line BL2,
respectively, so that positional data of the color-dot forming
region can be prescribed by the first dot pitch and the second dot
pitch, facilitating the design.
[0125] (Features of Color Filter Substrate)
[0126] The color filter substrate 1000 obtained by the
manufacturing method described above, as shown in FIGS. 1 and 2,
has the following configurations reflecting features of the
manufacturing method.
[0127] (a) Each color-dot 100a that constitutes the color filter
element 100 is located at a distance (NPx, N is an integer) of at
an integral multiple of the first dot pitch Px of the x direction
from the first base line BL1 of the y direction. Furthermore, each
color dot 100a is located at a distance (N'Py, N' is an integer) of
an integral multiple of the second dot pitch Py of the y direction
from the second base line BL2 of the x direction.
[0128] (b) The spacing between the color filter elements 100 is
established as follows. A spacing Lx1 in the direction of the
second base line BL2 is an integral multiple (nPx, n is an integer
except zero) of the first dot pitch Px. A spacing Ly1 in the
direction of the first base line BL1 is an integral multiple (n'Py,
n' is an integer except zero) of the second dot pitch Py.
[0129] That is, a first element pitch PEx in the direction of the
second base line BL2 is an integral multiple of the first dot pitch
Px while a second element pitch PEy in the direction of the first
base line BL1 is an integral multiple of the second dot pitch
Py.
[0130] (c) A spacing Lx2 from the first base line BL1 to the first
line of the color filter elements 100 is an integral multiple (mPx,
m is an integer) of the first dot pitch Px. A spacing Ly2 from the
second base line BL2 to the first row of the color filter elements
100 is an integral multiple (m'Py, m' is an integer) of the second
dot pitch Py.
[0131] (Modifications of Color Filter Substrate)
[0132] [First Modification]
[0133] FIG. 7 is a schematic showing a manufacturing method of a
color filter substrate including color filter elements 100 arranged
in a delta array. In this example, two first base lines BL1 and
BL1' are established in the y direction, while two second base
lines BL2 and BL2' are established in the x direction.
[0134] In this example, in the x direction, the odd number-th line
of the color dot arrays is located at a distance of an integral
multiple of the first dot pitch Px from one first base lines BL1,
while the even number-th line of the color dot arrays is located at
distance of an integral multiple of the first dot pitch Px from the
other first base lines BL1'. Similarly, in the y direction, the odd
number-th row of the color dot arrays is located at a distance of
an integral multiple of the second dot pitch Py from one second
base lines BL2, while the even number-th row of the color dot
arrays is located at distance of an integral multiple of the second
dot pitch Py from the other second base lines BL2'.
[0135] The spacing in the x direction between one first base lines
BL1 and the other first base lines BL1' is 0.5 Px, while the
spacing in the y direction between one second base lines BL2 and
the other second base lines BL2' is 0.5 Py.
[0136] This example also basically satisfies the conditions (a) to
(c) described in the manufacturing method of the stripe-type color
filter substrate. In addition, in the example shown in FIG. 7, the
positional reference of the color dot 100a is prescribed by the
color-dot center.
[0137] Also, in this example, just like in the embodiment described
above, positional data of the color-dot-forming region can be
prescribed by the first dot pitch and the second dot pitch,
facilitating the design.
[0138] [Second Modification]
[0139] FIGS. 16(a) to (c) show a modification of a color filter
substrate, where: FIG. 16(a) is a plan view of color filter
elements constituting the color filter substrate; FIG. 16(b) is a
sectional view taken along plane D-D of FIG. 16(a); FIG. 16(c) is a
sectional view taken along plane E-E of FIG. 16(a), where like
reference characters designate substantially like functional
portions common to those in FIGS. 2 and 3.
[0140] The color filter element 100 of the color filter substrate
in this example is different from the light-transmission type color
filter substrate described above with regard to the
semi-transmissive reflection type.
[0141] The color filter element 100 according to the embodiment, as
shown in FIGS. 16(a)-(c), includes the transparent substrate 10, a
reflection layer 26 to reflect light (visible light), and a
transmission layer 28 to allow light to be transmitted. The bank
layer 24 is formed on the reflection layer 26. Within a
colored-layer-forming region defined by the bank layer 24, colored
layers (colored dots) 32 (32(R), 32(G), and 32(B)) are arranged.
The overcoat layer 40 is further formed on the colored layers 32 to
perform flattening.
[0142] The transmission layer 28 is formed so as to lie in the
center of the colored-layer forming region defined by the bank
layer 24. The colored layers (colored dots) 32 are formed by the
inkjet method. The colored layer formed by the inkjet method
generally has a tendency to rise in the middle part of the
colored-layer forming region. Therefore, by forming the
transmission layer 28 in the middle part of the
colored-layer-forming region, optical film thicknesses during
reflection display and during transmission display can be
substantially equalized or the both can be drawn near, resulting in
the reflection color display and transmission color display
approximating each other.
[0143] That is, during reflection display, display light, as shown
by the arrow X0 in FIG. 16(b), passes a thin-film portion of the
colored layer 32 by reciprocating, whereas, during transmission
display, display light, as shown by the arrow X1 in FIG. 16(b),
passes through a thick-film portion of the colored layer 32.
Therefore, by forming the colored layer 32 to be convex in section
as shown in FIGS. 16(b) and (c), the optical film thicknesses
during reflection display and during transmission display can be
approximated.
Second Embodiment
[0144] FIG. 8 is a schematic perspective view of a color
luminescent substrate (display motherboard) as an example of the
color display substrate applied in the present invention; FIG. 9 is
a plan view of a significant part of a color luminescent element
(unit constituting the display) forming the color luminescence
substrate; and FIG. 10(D) is a sectional view taken along plane C-C
of FIG. 9.
[0145] (Overview of Color Luminescence Substrate)
[0146] An overview of a color luminescent substrate 2000 according
to a second embodiment will be described. The color luminescent
substrate 2000 includes a transparent substrate 104 and plural
color luminescent elements 200 formed on the substrate 104 in a
matrix pattern. A plurality of color illuminators can be obtained
by cutting the color luminescence substrate 2000 at predetermined
positions afterward.
[0147] The color luminescent element 200 according to the
embodiment, as shown in FIGS. 9 and 10(D), includes the transparent
substrate 104, a bank layer 105, which does not allow light
(visible light) to be substantially transmitted, and a
light-luminescent region 130. The luminescent region 130 is a
region defined by the bank layer 105, and it includes a first
electrode (positive electrode in this example) deposited on the
substrate 104, a positive-hole injection layer, a luminescent
layer, and a second electrode (negative electrode in this example).
The substrate 104 functions as a surface, from which light is
emitted, while serving as a supporter. Therefore, the material of
the substrate 104 is selected in consideration of
light-transmitting characteristics and thermal stability. A glass
substrate and transparent plastic are examples of the material of
the transparent substrate.
[0148] According to the embodiment, the positive-hole injection
layer represents a layer that can inject a positive hole into the
luminescent layer from the positive electrode and also has a
transporting function of the positive hole. A positive-hole
transport layer may be separately provided along with the
positive-hole injection layer.
[0149] According to the embodiment, in the same way as in the first
embodiment, the length of one dot pitch of the luminescent region
130 and the bank layer 105 is prescribed to as one color dot (dot
element) 200a, as shown in FIG. 9. In the description below, the
dot pitch of the color dots 200a forming the color luminescent
element 200 in the X direction is referred to as a first dot pitch
Px, while the dot pitch in the Y direction is referred to as a
second dot pitch Py. In the color luminescent substrate 2000, as
shown in FIG. 8, the element pitch of the color luminescent element
200 in the X direction is referred to as a first element pitch PEx,
while the element pitch in the y direction is referred to as a
second element pitch PEy. In addition, the dot pitch and element
pitch are the same as those in the first embodiment.
[0150] The bank layer 105 has a predetermined pattern. The bank
layer 105 defines regions to be formed by luminescent layers, and
functions as a barrier to prevent adjacent luminescent layers from
being mixed with each other (color mixture).
[0151] The bank layer 105 is formed of a resin layer, on which
photolithography can be performed in the same way as in the first
embodiment.
[0152] The light-luminescent region 130 includes plural luminescent
layers 106 (R), 107 (G), and 108 (B), each for red, green, and
blue, which constitute the three primary colors. These luminescent
layers are arranged according to a predetermined arrangement
pattern, such as striped arrangement, delta arrangement, mosaic
arrangement, and square arrangement, and one pixel is constituted
of continuous luminescent layers with three respective colors.
[0153] Features of the color luminescent substrate 2000 and the
color luminescent element 200 according to the embodiment will be
described below.
[0154] (Manufacturing Method of Color Luminescent Substrate)
[0155] Referring now to FIGS. 10(A) to (D), an overview of a
manufacturing method of the color luminescent substrate will be
described. FIGS. 10(A) to (D) show manufacturing steps of the color
luminescent substrate using organic EL (referred to as an organic
EL substrate below).
[0156] (A) First Electrode and Bank Layer Forming
[0157] First, as shown in FIG. 10(A), first electrodes (referred to
as a pixel electrode below) 101, 102, and 103 with predetermined
patterns are formed on the transparent substrate 104.
Photolithography, vacuum deposition, sputtering, and pyrosol are
examples of a forming method of the pixel electrode; however,
photolithography is preferable. A transparent electrode is
preferable as the pixel electrode. Tin oxide, ITO, and compound
oxide of indium oxide and zinc oxide are examples of the material
of the transparent electrode.
[0158] Then, the bank layer 105 is formed of photosensitive
polyimide so as to separate between the adjacent transparent
electrodes. The bank layer 105 functions as a black matrix layer
while functioning as a barrier as well, so as to enhance contrast
and to prevent the color mixture of luminescent materials, and
further to prevent light from leaking from between adjacent color
dots.
[0159] The material of the bank layer 105 is not specifically
limited as long as it has durability against the solvent of an EL
material. An organic material is preferable, such as an acrylic
resin, epoxy resin, and photosensitive polyimide, because they can
be Teflonized (registered trademark) by fluorocarbon gas plasma
polymerization. The material may be also a deposited bulkhead
having an underlayer of an inorganic material, such as liquid
glass. The bank layer 105 may also be a black resist made of the
above-mentioned material having carbon black mixed therewith.
Photolithography is an example of a forming method of the bank
layer 105.
[0160] Before coating the substrate with ink for the positive-hole
injection layer and the positive-hole transport layer, which is
further formed on demand, continuous plasma polymerization may be
performed on the substrate 104 using oxygen gas and fluorocarbon
gas plasma. Thereby, the surface of the bank layer 105 is made to
be water-repellent while surfaces of the transparent pixel
electrodes 101, 102, and 103 are made to be water-receptive, so
that wettability of the substrate relative to inkjet-liquid
droplets can be controlled. Any of apparatuses generating plasma
under vacuum pressure and under atmospheric pressure may be
similarly used as a plasma generating apparatus.
[0161] (B) Luminescent Layer Forming
[0162] Next, as shown in FIG. 10(A), ink for the positive-hole
injection layer is ejected from the head 1 of an inkjet printing
apparatus 109 so as to supply the ink on the pixel electrodes 101,
102, and 103. Then, solvent is removed and heat-treatment is
further performed so as to form a positive-hole injection layer 120
incompatible with ink for the luminescent layer. According to the
embodiment, the same material for positive-hole injection is used
for each color dot; however, in some cases, the positive-hole
injection layer (or the positive-hole transport layer) may be
formed by using positive-hole injection materials (or positive-hole
transport materials) respectively appropriate to each luminescent
layer.
[0163] Furthermore, as shown in FIG. 10(B), the positive-hole
injection layer 120 is sequentially coated thereon with ink for the
red luminescent layer and ink for the green luminescent layer by
the inkjet system. Then, solvent is removed and heat-treatment is
successively performed in an atmosphere of nitrogen so as to form
the red luminescent layer 106 and the green luminescent layer 107
by curing or conjugating the ink composition. The luminescent layer
conjugated by the heat-treatment is insoluble in solvent.
[0164] By such an inkjet system, very small patterning can be
simply performed in a short period of time. Also, by changing the
ink solid-content concentration and the amount of ink injection,
the film thickness can be changed.
[0165] Before forming the luminescent layer, the continuous plasma
polymerization may be performed on the positive-hole injection
layer 120 using oxygen gas and fluorocarbon gas plasma. Thereby, a
fluorine compound layer is formed on the positive-hole injection
layer (or positive-hole transport layer) 120 so as to enhance
ionization potential, enabling the organic EL substrate with high
efficiency of positive-hole injection to be provided.
[0166] (C) Luminescent Layer Forming
[0167] Then, as shown in FIG. 10(C), the blue luminescent layer 108
is formed on the positive-hole injection layer 120 on the pixel
electrode 103. By the steps described above, the luminescent layers
106, 107, and 108 of the three primary colors, one each for red,
green, and blue, are formed.
[0168] In the forming step of the blue luminescent layer 108,
layers 108a and 108a made of the same material as that of the blue
luminescent layer 108, along with the blue luminescent layer 108,
are formed on the red luminescent layer 106 and the green
luminescent layer 107. These layers 108a reduce the height
difference between the luminescent layers 106 and 107 and the bank
layer 105 so as to flatten them. By the flattening of the bank
layer 105 relative to the neighborhood, the second electrode
(negative electrode) can be formed with a high degree of accuracy
in a flat state. As a result, short-circuit between the upper and
lower electrodes can be securely prevented. By adjusting the film
thickness of the blue luminescent layer 108, the layers 108a formed
on the red luminescent layer 106 and green luminescent layer 107
function as an electron-injection-and-transform layer and do not
emit blue light.
[0169] The method of forming the blue luminescent layer 108 is not
specifically limited. A spin coating method or inkjet method, which
are general as a wet system, may be employed.
[0170] As in the embodiment, two colors in the organic luminescent
layer are formed by the inkjet method while the other one color
being formed by a conventional coating method, so that even a
luminescent material, which is not so applicable to the inkjet
method, can be used for a full-color organic EL substrate by
combining with other organic luminescent materials applicable to
the inkjet method, resulting in increasing of the degree of element
design. A printing method, transfer method, dipping method, spin
coating, cast coating, capillary method, roll coating, and bar
coating are examples of a coating method other than the inkjet
system that can be used.
[0171] (D) Negative Electrode Forming
[0172] Then, as shown in FIG. 8(D), a negative electrode (opposing
electrode) 113 is formed. A metallic thin-film electrode is
preferable as the negative electrode 113. Magnesium, silver,
aluminum, and lithium are examples of a metal for the negative
electrode. Other than those, a material with a small work function
may also be used, such as an alkaline-earth metal, such as an
alkali metal and potassium, and an alloy of these materials. A
fluorinated metal may also be applicable. Such a negative electrode
113 may be formed by vapor deposition, sputtering, or the like.
[0173] A protection film may be further formed on the negative
electrode 113. By forming the protection film, the negative
electrode 113 and the luminescent layers 106, 107, and 108 can be
prevented from degradation, damages, and breaking away.
[0174] An epoxy resin, acrylic resin, and liquid glass are examples
of a material of such a protection film. Spin coating, cast
coating, dipping method, bar coating, roll coating, and capillary
method are examples of a forming method of the protection film.
[0175] The opposing electrode 113 may be provided depending on the
configuration of the electro-optical apparatus, to which a color
illuminator is applied. Then, by cutting the color luminescent
substrate 2000 at predetermined positions, plural color
illuminators are obtained.
[0176] In the manufacturing method described above, known
substances may be used as a material of each layer. Also, materials
disclosed in Japanese Unexamined Patent Application Publication No.
11-134320 and Japanese Unexamined Patent Application Publication
No. 11-250486, which are applied by the Applicant, may be used as
materials of the positive-hole injection layer and luminescent
layer.
[0177] According to the manufacturing method described above,
two-color luminescent layers in the luminescent layers of the three
primary colors are formed by the inkjet system; however, all
three-color luminescent layers may be of course formed by the
inkjet system. Furthermore, in the manufacturing method described
above, the positive-hole injection layer (positive-hole transport
layer) and the luminescent layer to form the color dots are formed
by the inkjet system; however, the luminescent layer may only be
formed.
[0178] (Features of Manufacturing Method)
[0179] FIG. 11 is a plan view illustrating the manufacturing method
according to the present invention and showing steps corresponding
to FIGS. 10 (A) and (B). In FIG. 11, to simplify the drawing, the
color dots 200a and color-dot-forming regions 200b are shown. In
FIG. 11, forming stripe-type pixels is exemplified.
[0180] According to the embodiment, the color dots 200a are
basically formed by the same method as that in the color dots 100a
according to the first embodiment. That is, according to the first
embodiment, the colored layer forming the color filter element is
formed by the inkjet system, whereas according to the embodiment,
it is different in the point that the positive-hole injection layer
and the luminescent layer to form the color luminescent element are
formed by the inkjet system.
[0181] In the example of FIG. 11, the first base line BL1 and
second base line BL2 are established along the y direction and x
direction, respectively.
[0182] According to the embodiment, the inkjet head 1 for use in
the inkjet printing is moved relative to the substrate 104 in the x
direction so as to supply ink (ink for the positive-hole injection
layer and the luminescent layer) to the color-dot forming regions
200b, specifically to the light-luminescent regions 130 (see FIGS.
10(A) and (B)) to form a positive-hole injection layer and
luminescent layer, completing the color dots 200a.
[0183] The inkjet head 1, in the same way as the first embodiment,
has a nozzle array having plural nozzles 1a arranged linearly. In
the nozzle array, the nozzles 1a are arranged at a predetermined
pitch in the direction of the first base line BL1 (the same pitch
as the second dot pitch Py, in this example). Also, the nozzle
array of the inkjet head 1 is set to have plural rows (two rows, in
this example) of the forming regions of the color luminescent
elements 200 in the direction of the first base line BL1.
[0184] The base lines BL1 and BL2, the color luminescent element
200, the color dot 200a, and the color-dot-forming region 200b, in
the same way as in the first embodiment, satisfy the following
conditions (a) to (c).
[0185] (a) Each color-dot-forming region 200b for the color
luminescent element 200 is established to lie at a distance (N'Px,
N' is an integer) of at least substantially an integral multiple of
the first dot pitch Px of the x direction from the first base line
BL1 of the y direction. Furthermore, each color-dot-forming region
200b is established to lie at a distance (NPy, N is an integer) of
substantially an integral multiple of the second dot pitch Py of
the y direction from the second base line BL2 of the x
direction.
[0186] (b) The spacing between the color luminescent elements 200
is established as follows. The spacing Lx1 in the direction of the
second base line BL2 is set to be an integral multiple (nPx, n is
an integer except zero) of the first dot pitch Px. The spacing Ly1
in the direction of the first base line BL1 is set to be an
integral multiple (n'Py, n' is an integer except zero) of the
second dot pitch Py.
[0187] That is, a first element pitch PEx in the direction of the
second base line BL2 is established to be an integral multiple of
the first dot pitch Px, while a second element pitch PEy in the
direction of the first base line BL1 is established to be an
integral multiple of the second dot pitch Py.
[0188] (c) The spacing Lx2 from the first base line BL1 to the
first line of the color luminescent elements 200 is set to be an
integral multiple (mPx, m is an integer) of the first dot pitch Px.
The spacing Ly1 from the second base line BL2 to the first row of
the color luminescent elements 200 is set to be an integral
multiple (m'Py, m' is an integer) of the second dot pitch Py.
[0189] When the conditions (b) and (c) are satisfied, the condition
(a) is satisfied. Therefore, according to the embodiment, in order
to form the color dots 200a by the inkjet system using the inkjet
head 1, ink-ejecting positions are established so as to satisfy the
condition (a), or the condition (b) plus the condition (c).
[0190] On the basis of the positional information of the base lines
BL1 and BL2 and the information required to form the positive-hole
injection layer and luminescent layer, ink is ejected at a
predetermined position so as to form the color dot 200a. The
information required to form the color dot 200a is appropriately
selected based on the operating method of the inkjet head, or the
like, and it includes the information to specify the position of
the color-dot-forming region, the information to specify the color
of the luminescent layer, and the information to specify the
ejection timing to the color-dot-forming region, for example.
[0191] Next, referring to FIG. 1, the method of forming the color
dot 200a will be more specifically described. FIG. 11 shows a state
that the inkjet head 1 has been moved until the first line of the
color-dot-forming region in the second-line color filter element.
Black circles denote regions in which ink is ejected with the
nozzles 1a of the inkjet head 1, while white circles denote regions
in which ink is not ejected with the nozzles 1a of the inkjet head
1.
[0192] In this example, the inkjet head 1 is moved in the x
direction relative to the substrate 10, so that based on the
above-mentioned information required to form the color dot, the
positive-hole injection layer, the positive-hole transport layer,
which is formed on demand, and the luminescent layer are
sequentially formed.
[0193] First, the positive-hole injection layer (see FIG. 10(a))
and the positive-hole transport layer, which is formed on demand,
are formed. Then, the first-color color dot 200a (red (R) in this
example) is formed. During one round movement of the inkjet head 1
in the x direction, the positive-hole injection layers and the
positive-hole transport layers, which are formed on demand, and the
first-color luminescent layers in the first and the second row in
the y direction are formed.
[0194] Then, the inkjet head 1 is moved relative to the substrate
10 in the y direction so as to form the first-color color dots of
the third and the fourth row. Afterward, the first-color color dots
are similarly formed every two rows.
[0195] Next, using the inkjet head 1 with different colors, the
color dots 200a of the second-color (blue or green) and the
third-color (remained color) are formed in the same way as in the
first-color. In such a manner, the color dots 200a of at least the
positive-hole injection layer and the three primary colors are
formed at predetermined positions so as to obtain the color
luminescent substrate 2000 having plural color luminescent elements
200 arranged in a matrix pattern.
[0196] One of the three colors may be formed by a coating method
other than the inkjet system as the method shown in FIG. 10.
[0197] According to the manufacturing method of the embodiment, as
in the same way as in the first embodiment, the ejecting timing can
be set by the dot pitch, facilitating the design.
[0198] (Features of Color Luminescent Substrate)
[0199] The color luminescent substrate 2000 obtained by the
manufacturing method described above has the following
configurations reflecting features of the manufacturing method.
[0200] (a) Each color-dot 200a for constituting the color
luminescent element 200, as shown in FIGS. 8 and 11, is located at
a distance (NPx, N is an integer) of an integral multiple of the
first dot pitch Px of the x direction from the first base line BL1
of the y direction. Furthermore, each color dot 200a is located at
a distance (N'Py, N' is an integer) of an integral multiple of the
second dot pitch Py of the y direction from the second base line
BL2 of the x direction.
[0201] (b) The spacing between the color luminescent elements 200
is as follows. The spacing Lx1 in the direction of the second base
line BL2 is an integral multiple (nPx, n is an integer except zero)
of the first dot pitch Px. The spacing Ly1 in the direction of the
first base line BL1 is an integral multiple (n'Py, n' is an integer
except zero) of the second dot pitch Py.
[0202] That is, the first element pitch PEx in the direction of the
second base line BL2 is an integral multiple of the first dot pitch
Px, while the second element pitch PEy in the direction of the
first base line BL1 is an integral multiple of the second dot pitch
Py.
[0203] (c) The spacing Lx2 from the first base line BL1 to the
first line of the color luminescent elements 200 is an integral
multiple (mPx, m is an integer) of the first dot pitch Px. The
spacing Ly2 from the second base line BL2 to the first row of the
color luminescent elements 200 is an integral multiple (m'Py, m' is
an integer) of the second dot pitch Py.
[0204] Also, in the color luminescent substrate, the pixels in the
delta arrangement are the same as described in the first embodiment
(see FIG. 7).
Third Embodiment
[0205] (Electro-Optical Apparatus)
[0206] FIG. 13 is a sectional view of a significant part of a color
liquid-crystal display 1100, as an example of the electro-optical
apparatus, in which a color filter 1000A is assembled, which is
obtained from the color filter substrate 1000 according to the
first embodiment.
[0207] The color liquid-crystal display 1100 is configured by
combining the color filter 1000A with an opposing substrate 80, and
enclosing a liquid-crystal composition 70 between them. On the
internal surface of the one substrate 80 of the liquid-crystal
display 1100, TFT (thin-film transistor) elements (not shown) and
pixel electrodes 52 are formed in a matrix pattern. As the other
substrate, the color filter 1000A is placed so as to arrange the
red, green, and blue colored layers at positions opposing the pixel
electrodes 52. On the respective opposing surfaces of the substrate
80 and the color filter 1000A, oriented films 60 and 62 are formed.
The rubbing treatment is performed on the oriented films 60 and 62
so as to orientate liquid crystal molecules in a predetermined
direction. Polarizing plates 90 and 92 are respectively bonded on
external surfaces of the substrates 10 and 80. As a backlight, the
combination of a fluorescent lamp (not shown) and a scatter plate
is generally used, and the display is performed by functioning the
liquid-crystal composition as an optical shutter for changing
transmissivity of the backlight light.
[0208] FIG. 17 is a sectional view of an essential part of a color
EL display 2100 as an example of the electro-optical apparatus, in
which a color illuminator 2000A is assembled, which is obtained
from the color luminescent substrate 2000 according to the second
embodiment.
[0209] The color EL display 2100 is configured by arranging the
color illuminators 2000A on a frame 112. On the substrate 104 of
the color illuminators 2000A, switching elements 202, such as the
TFT (thin-film transistor) elements, are formed in a matrix
pattern. The adjacent switching elements 202 are separated by an
insulating layer 206.
[0210] The light-luminescent region 130 includes a luminescent
layer 122, the positive-hole injection layer 120, and a pair of
electrodes of first and second electrodes 204 and 208.
[0211] The luminescent layers 122 are arranged on the substrate 104
in a predetermined matrix pattern while being defined by the bank
layers 105. The luminescent layer 122 is formed between the first
electrode (positive electrode) 204 and the second electrode
(negative electrode) 208. The luminescent layer 122 includes plural
luminescent layers having each of the three primary colors of red,
green, and blue. The luminescent layer 122 is made of an organic
material capable of emitting by electroluminescence, for example.
Also, between the positive electrode 204 and the luminescent layer
122, the positive-hole injection layer 120 is formed.
Fourth Embodiment
[0212] (Electronic Device)
[0213] Examples of an electronic device using a liquid crystal
display will be described below as the electro-optical apparatus
according to the present invention.
[0214] (1) Digital Still Camera
[0215] A digital still camera using the color liquid-crystal
display 1100 as a finder will be described. FIG. 14 is a
perspective view of the configuration of the digital still camera,
further simply showing the connection to external instruments.
[0216] In a general camera, the film is exposed to a light figure
of an object, whereas in a digital still camera 3000, a light
figure of an object is photo-electrically converted by an image
pick-up element such as a CCD (charge coupled device) so as to form
an image pick-up signal. A case 2202 of the digital still camera
3000 is provided with a liquid crystal panel of the above-mentioned
color liquid-crystal display 1100 formed on the back surface (the
front side in FIG. 14), and display is performed by the liquid
crystal panel based on the pick-up signal by the CCD. Therefore,
the liquid-crystal display 1100 functions as a finder to display an
object. A light-receiving unit 2204, including an optical lens and
a CCD, is arranged on the front surface of the case 2202 (back side
in FIG. 14).
[0217] When a user pushes a shutter button 2206 down after
confirming an object image displayed on the liquid-crystal display
1100, an image pick-up signal of the CCD at that time is
transferred and stored in a memory of a circuit board 2208. A side
face of the case 2202 of the digital still camera 3000 is provided
with video-signal-output terminals 2212 and an input-output
terminal 2214 for data communication. As shown in FIG. 14, to the
former video-signal-output terminals 2212, a television monitor
2300 is connected, while to the later input-output terminal 2214, a
personal computer 2400 is connected, when being demanded. Moreover,
by a predetermined operation, the image pick-up signal stored in
the memory of the circuit board 2208 is output into the television
monitor 2300 or the personal computer 2400.
[0218] (2) Portable Telephone, Other Electronic Devices
[0219] FIGS. 15(A), (B), and (C) are perspective views of other
electronic devices using the liquid crystal display as the
electro-optical apparatus according to the present invention. FIG.
15(A) shows a portable telephone 4000 having the liquid crystal
display 1100 on the upper front surface; FIG. 15(B) shows a wrist
watch 5000 having a display on the central front surface of a body
using the liquid crystal display 1100; FIG. 15(C) shows a portable
information device 6000 having a display formed of the liquid
crystal display 1100 and an input section 5100.
[0220] These electronic devices, other than the liquid crystal
display 1100, although not shown, include various circuits, such as
a display-information-output source, display-information-processing
circuit, and a clock-generating circuit, and a display-signal
generating section including a power supply circuit to supply
electric power to these circuits. In the case of the portable
information device 6000, for example, a display signal generated by
the display-signal generating section based on the information
input from the input section 5100 is supplied to the display so as
to form display images.
[0221] Examples of various electronic devices in which the color
liquid-crystal display 1100 according to the present invention is
assembled, other than the digital still camera, portable telephone,
wrist watch, and portable information device, include an electronic
pocketbook, pager, POS-terminal, IC card, mini-disk player, liquid
crystal projector, personal computer (PC) applicable to
multi-media, engineering work station (EWS), notebook personal
computer, word processor, television, view-finder type or
monitor-straight-gaze type video-tape-recorder, electronic desk-top
calculator, car navigation apparatus, apparatus having a touch
panel, and clock.
[0222] In addition, in the liquid crystal display panel, when
classifying by the driving system, a simple matrix-liquid-crystal
display panel using no switching element in the panel itself,
static drive liquid-crystal display panel, three-terminal switching
element represented by the TFT (thin film transistor), and
active-matrix liquid-crystal display panel using two-terminal
switching element represented by the TFD (thin film diode) can be
used. When classifying by electro-optical characteristics, various
types of liquid-crystal display panels, such as a TN type, STN
type, guest-host type, phase-transition type, and ferroelectric
type, can be used.
[0223] The apparatus according to the present invention has been
described by exemplifying several embodiments; however, the present
invention may be modified in various ways within the spirit and
scope of the invention. For example, in the embodiment described
above, the liquid-crystal display and EL display are described as
image displaying devices (electro-optical display) of the
electro-optical apparatus; however, the present invention is not
limited to these apparatuses, and various electro-optical devices
can be used, such as a thin-thickness cathode-ray-tube, compact
television using a liquid crystal shutter, electroluminescence,
plasma display, CRT display, FED (field emission display) panel,
and electrophoresis display, for example.
* * * * *