JP2004177539A - Color filter for liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter for liquid crystal display device which can be manufactured within a shortened delivery without expending a considerable time for adjustment relating to an alignment mark and mutual confirmation and does not cause the mistake of marks and the like when a new plate of the color filter for a liquid crystal display device to which various functions are added is manufactured. <P>SOLUTION: An alignment mark assembly 10 to which the respective the alignment marks gather is used as the alignment mark. When color pixels, transparent conductive films and annexed layers are formed, the relevant alignment mark in the alignment mark assembly 10 is selected and used. The alignment mark assembly 10 is disposed on a specified position of the peripheral part of a glass substrate 30 at the same time with the formation of a black matrix. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a color filter for a liquid crystal display device. In particular, when designing a new version of a color filter for a liquid crystal display device, the alignment mark is confirmed between the liquid crystal display device manufacturer and the color filter manufacturer. The present invention relates to a color filter for a liquid crystal display device which can be produced with a shorter delivery time without spending time.
[0002]
[Prior art]
FIG. 4 is a plan view schematically showing an example of a color filter used in the liquid crystal display device. FIG. 5 is a cross-sectional view taken along line XX ′ of the color filter shown in FIG.
As shown in FIGS. 4 and 5, the color filter (4) used in the liquid crystal display device is composed of a black matrix (41), a colored pixel (42), and a transparent conductive film (43) on a glass substrate (40). Are sequentially formed.
FIGS. 4 and 5 schematically show a color filter, in which twelve colored pixels (42) are shown. In an actual color filter, for example, several hundred pixels are displayed on a 17-inch diagonal screen. Many colored pixels of about μm are arranged.
[0003]
As a method for manufacturing a color filter having the above structure, which is used in many liquid crystal display devices, first, a black matrix is formed on a glass substrate to form a black matrix substrate, and then a black matrix on the black matrix substrate is formed. A method is widely used in which a colored pixel is formed by aligning with the pattern described above, and a transparent conductive film is formed by aligning.
The black matrix (41) is a matrix having light-shielding properties, the colored pixel (42) has, for example, a filter function of red, green, and blue, and the transparent conductive film (43) is transparent. Are provided as simple electrodes.
[0004]
The black matrix (41) is composed of a matrix portion (41A) between the colored pixels (42) and a frame portion (41B) surrounding a peripheral portion of a region (display portion) in which the colored pixels (42) are formed. I have.
The black matrix determines the positions of the colored pixels of the color filter, makes the size uniform, and, when used in a display device, blocks undesired light and makes the image of the display device uniform without unevenness. And a function of forming an image with improved contrast.
[0005]
The production of the black matrix substrate, chromium as the material of the black matrix on a glass substrate (40) (Cr), a metal such as chromium oxide (CrO _X), or a metal compound was formed into a thin film, deposition On the formed thin film, for example, an etching resist pattern is formed using a positive photoresist, and then the exposed portion of the formed metal thin film is etched and the etching resist pattern is stripped to obtain Cr, CrO _A method of forming a black matrix (41) made of a metal thin film such as _X has been adopted.
Alternatively, a method of forming a black matrix (41) on a glass substrate (40) by photolithography using a black photosensitive resin for forming a black matrix is adopted.
[0006]
The colored pixels (42) are formed by providing a coating film on the black matrix substrate using, for example, a negative photoresist in which a pigment such as a pigment is dispersed, and exposing and developing the coating film. A method of forming a colored pixel has been adopted.
The transparent conductive film (43) is formed by, for example, forming a transparent conductive film on a black matrix substrate on which a colored pixel is formed by sputtering using ITO (Indium Tin Oxide). .
[0007]
The color filter (4) shown in FIGS. 4 and 5 represents one color filter corresponding to one liquid crystal display device. When a large number of color filters are manufactured, one color filter is used. The color filter corresponding to the device is manufactured in a state of being mounted on a large-sized glass substrate.
FIG. 6 is a plan view showing an example in which, for example, a 17-inch diagonal color filter (4) is attached to a large-sized glass substrate (60) of about 650 mm × 850 mm on four sides to be manufactured.
[0008]
The color filter (4) shown in FIGS. 4 and 5 has a basic function as a color filter used in a liquid crystal display device. The liquid crystal display device realizes full color display by incorporating such a color filter, dramatically expands its application range, and creates many products using the liquid crystal display device such as a liquid crystal color TV and a notebook PC. Was done.
With the improvement of liquid crystal display devices and the development and practical use of various liquid crystal display devices, various functions are added to the color filters used in liquid crystal display devices, as follows, in addition to the above basic functions. It became so.
[0009]
1) Spacer function In a conventional liquid crystal display device, transparent spherical particles (beads) of glass or synthetic resin called spacers are dispersed in order to form a gap between substrates. Since this spacer is a transparent particle, if a pixel contains a spacer with liquid crystal, light leaks through the spacer during black display, and the substrate on which the liquid crystal material is sealed. The presence of the spacer between them disturbs the alignment of liquid crystal molecules near the spacer, causing light leakage at this portion, lowering the contrast and adversely affecting display quality.
[0010]
As a technique for solving such a problem, a method of forming a photo spacer (projection) having a spacer function at a position of a black matrix between pixels using a photosensitive resin by a photo fabrication method has been developed.
FIG. 7 is a partial sectional view of such a color filter for a liquid crystal display device. As shown in FIG. 7, the color filter (7) for a liquid crystal display device has a black matrix (41), a colored pixel (42), and a transparent conductive film (43) sequentially formed on a glass substrate (40). A photo spacer (44) as a projection having a spacer function is formed on the transparent conductive film (43) above the black matrix (41). In a liquid crystal display device using such a color filter (7) for a liquid crystal display device, the photo spacer (44) is formed at a position avoiding the inside of the pixel, so that the above-mentioned improvement in contrast is observed.
[0011]
2) Orientation splitting function In a conventional liquid crystal display device, in order to uniformly align liquid crystal molecules, polyimide is applied in advance on a transparent conductive film provided on both substrates sandwiching the liquid crystal, and the surface thereof is coated. A uniform rubbing process.
However, in a TN type liquid crystal used in many liquid crystal display devices, it is difficult in principle to obtain a wide viewing angle. Quality deteriorates. That is, there is a problem that the viewing angle with good contrast is narrow.
[0012]
One technique for solving such a problem is to control the orientation direction of liquid crystal molecules in one pixel not in one direction but in multiple directions, and to perform uniform halftone display in multiple directions. In other words, an alignment-divided vertical alignment type liquid crystal display device (MVA, Multi-domain Vertical Alignment-LCD) having a wide viewing angle has been developed.
[0013]
FIG. 8 is an explanatory diagram schematically showing a cross section of such an MVA-LCD. As shown in FIG. 8, the MVA-LCD (80) includes a TFT-side substrate (20) provided with alignment control protrusions (22a) and (22b) via liquid crystal molecules (21), and an alignment control protrusion (23). ) Is provided, and the alignment control projections (22a) and (22b) and the alignment control projection (23) are provided at alternate positions within one pixel.
[0014]
As shown by the thick white arrow in FIG. 8, in the state at the time of voltage application, the liquid crystal molecules between the alignment control projections (22a) to (23) in one pixel are inclined diagonally to the left in FIG. The liquid crystal molecules between the control protrusion (23) and the alignment control protrusion (22b) are inclined rightward. That is, the alignment of the liquid crystal molecules is controlled by providing projections instead of the rubbing treatment.
In the example shown in FIG. 8, one pixel is divided into two, and the tilt direction of liquid crystal molecules is two in one pixel, so that a liquid crystal display device having excellent viewing angle characteristics is obtained.
[0015]
3) High reliability function When high reliability is required as a liquid crystal display device, to remove the heat resistance, moisture resistance, and chemical resistance of the colored pixels, and to elute from the colored pixels. A protective layer (overcoat layer) may be formed on a colored pixel as a barrier.
Alternatively, a protective layer (overcoat layer) may be formed in order to improve the sealing strength between the color filter and the TFT-side substrate.
Alternatively, when improving the display quality by making the alignment of liquid crystal molecules more uniform, a protective layer (overcoat layer) may be formed on the colored pixels to provide a color filter with high flatness.
[0016]
4) Combined transmission / reflection function A transflective liquid crystal display device having both a transmission type and a reflection type function in a single liquid crystal display device can be used under a bright outdoor environment or a dark indoor environment. . FIG. 11 is a sectional view of an example of a color filter used in a transflective liquid crystal display device. As shown in FIG. 11, this color filter has a black matrix (41), a colored pixel (42), and a transparent conductive film (43) formed on a glass substrate (40).
The colored pixel (42) includes a colored pixel (42Tr) for transmissive display and a colored pixel (42Re) for reflective display.
[0017]
The spectral characteristics of the transmissive display colored pixel (42Tr) and the reflective display colored pixel (42Re) are spectral characteristics suitable for transmissive display and reflective display, respectively. Therefore, when the liquid crystal display device is displayed as a transmission type, it has excellent brightness and chroma, and when it is displayed as a reflective type, it has an excellent brightness and chroma.
As the color filter, a total of six colored pixels of three colors of RGB of the colored pixel (42Tr) of the transmissive display and three colors of RGB of the colored pixel (42Re) of the reflective display are formed. That is, three colored pixels for transmissive display and three colored pixels for reflective display are formed.
[0018]
5) Spectral characteristic adjustment function FIG. 12 is a cross-sectional view of another example of the color filter used in the transflective liquid crystal display device. As shown in FIG. 12, this color filter has a black matrix (41), a colored pixel (42), and a transparent conductive film (43) formed on a glass substrate (40).
The colored pixel (42) includes a colored pixel (42Tr) for transmissive display and a colored pixel (42Re) for reflective display. The colored pixel (42Re) of the reflective display includes a colored portion (45) and a transparent portion (46).
[0019]
The colored portions (45) of the colored pixel (42Tr) for transmissive display and the colored pixel (42Re) for reflective display have spectral characteristics suitable for transmissive display. By providing the transparent portion (46) in the colored pixel (42Re) of the reflective display, the color light of the colored portion (45) and the white light of the transparent portion (46) are mixed, and the spectral characteristics of the colored pixel (42Re) of the reflective display. Are adjusted to appropriate spectral characteristics for reflection display. This transparent portion (46) is formed of a transparent resin.
[0020]
The spacer function, the orientation division function, the high reliability function, the combined transmission / reflection function, and the spectral characteristic adjustment function are added to the color filter (4) shown in FIG. One or more functions are added based on the use and specification of the filter.
These functions include forming and providing corresponding photo spacers, alignment control projections, protective layers (overcoat layers), colored pixels for reflective display, and transparent portions as layers accompanying the basic color filter. Positioning when forming an accompanying layer such as a photo spacer is performed with reference to a positioning mark provided in advance on a glass substrate.
[0021]
FIG. 9 shows an example of a color filter on which the above-described auxiliary layer is formed.
FIG. 9 is an enlarged view of one corner of the glass substrate (A) of the large-sized glass substrate (60) shown in FIG. 6 to explain the alignment marks. In the example shown in FIG. 9, a black matrix, a colored pixel, and a transparent conductive film are formed on a glass substrate (60), and a photo spacer is formed as an associated layer.
As shown in FIG. 6 and FIG. 9, this color filter is a large-sized glass substrate (60) of about 650 mm × 850 mm and four diagonal 17-inch color filters (4 (40)) attached to each other. (41B) is a frame portion, and (47) is a display portion. Colored pixels and photo spacers are formed in the display section (47) (not shown).
[0022]
(91) to (93) are marks used in the manufacturing process of the liquid crystal display device maker, such as alignment marks (91) between the color filter and the TFT side substrate, and cutting marks (92) of the liquid crystal display device. .
Further, (94) to (96) indicate positions where alignment marks used in a manufacturing process of a color filter maker are provided, and an alignment mark (94) for a colored pixel and an alignment mark (94) for a transparent conductive film are provided. 95), the position of the alignment mark (96) for the photo spacer.
[0023]
These alignment marks (94) to (96) are provided simultaneously when the black matrix is formed on the glass substrate. The colored pixels, the transparent conductive film, and the photo spacer use these alignment marks, that is, the black matrix. Are sequentially formed at predetermined positions with reference to.
The marks used by the liquid crystal display device maker and the alignment marks used by the color filter maker are also provided at the other three corners shown in FIGS. 6 (B), (C) and (D).
[0024]
FIG. 10 shows another example of the color filter in which the above-described auxiliary layer is formed. In this color filter, an alignment mark (94) for a colored pixel, an alignment mark (95) for a transparent conductive film, an alignment mark (96) for a photo spacer, and an alignment mark (97) for a transparent portion are provided. Is provided.
These alignment marks are provided in different positions and at different positions from the example of the color filter shown in FIG.
[0025]
In the design of marks in actual production, the shape and position of the mark used by the liquid crystal display device manufacturer are set by the liquid crystal display device manufacturer.
The alignment marks used by the color filter maker are selected based on the color filter specifications for each color filter item, and each of the alignment marks used by the color filter maker is selected. As shown in FIG. 9, the position of the alignment mark is a peripheral portion (margin) (F) of the glass substrate having a width of about 15 mm outside the color filter (4 (40)). Mutually confirm with the LCD manufacturer. The position of the alignment mark is appropriately set for each item, as shown in FIGS.
[0026]
Such a mutual confirmation between the liquid crystal display device manufacturer and the color filter manufacturer while making adjustments is not necessary in the case of a reprint for producing color filters of the same item again. It is necessary when producing eyes, and it takes a considerable amount of time to make adjustments and mutual confirmation.
This is an obstacle to the demands of liquid crystal display device manufacturers to further shorten the delivery time of products, particularly, to shorten the delivery time of new editions.
[0027]
In actual work handling many items, for example, it is later found that a mark used by a liquid crystal display device maker was set at a position of an alignment mark planned by a color filter maker, or, for example, In some cases, an error may occur such that it is later determined that the selection of the alignment mark used by the color filter maker is incorrect.
[0028]
Since the present invention has a strong know-how only in the practice in a factory, conventionally known documents and the like could not be found by ordinary investigation.
[0029]
[Problems to be solved by the invention]
The present invention has been made in order to solve the above-described problems, and in addition to the basic functions, a spacer function, an orientation division function, a high reliability function, a combined transmission / reflection function, a spectral characteristic adjustment function, and the like. When producing a new version of a color filter for a liquid crystal display device to which various functions are added, even if a plurality of alignment marks are selectively used, adjustment between a liquid crystal display device manufacturer and a color filter manufacturer, It does not require mutual confirmation, that is, it can be produced with shortened delivery time without spending a reasonable amount of time for adjustment and mutual confirmation, and without generating errors related to mark setting. It is an object to provide a color filter for a liquid crystal display device which can be produced.
[0030]
[Means for Solving the Problems]
The present invention provides a color filter for a liquid crystal display device, wherein a colored pixel, a transparent conductive film, and a colored pixel are used as an alignment mark when the colored layer is aligned and formed on a glass substrate on which a black matrix is formed. , A transparent conductive film, and an alignment mark aggregate in which each alignment mark for an associated layer is gathered, and corresponds to the alignment mark aggregate when the colored pixel, the transparent conductive film, and the associated layer are formed. A color filter for a liquid crystal display device, wherein an alignment mark to be used by selecting an alignment mark is provided at a fixed position on a peripheral portion of the glass substrate simultaneously with formation of a black matrix.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is an enlarged plan view showing an example of the alignment mark assembly according to the present invention. As shown in FIG. 1, the alignment mark assembly (10) includes an alignment mark (11) for a transparent conductive film, an alignment mark (12) for a colored pixel for transmissive display, and an alignment mark (12) for a colored pixel for reflective display. Alignment mark (13), alignment mark (14) for transparent part, alignment mark (15) for protective layer (overcoat layer), alignment mark (16) for photospacer, alignment alignment protrusion It is composed of an alignment mark (17) and spare spaces (18) and (19) for other alignment.
[0032]
An alignment mark (11) for a transparent conductive film and an alignment mark (12) for a colored pixel for transmissive display are alignment marks used when manufacturing a basic color filter, and other alignment marks are used. The mark is an alignment mark used when forming an accompanying layer such as a photo spacer on a basic color filter. That is, it is an alignment mark aggregate in which alignment marks used in the manufacturing process of the color filter manufacturer are gathered.
The size of the alignment mark assembly (10) is about 4 mm in length (a) and about 12 mm in width (b).
[0033]
FIGS. 2A, 2B, and 2C are plan views showing examples of alignment mark patterns that form the alignment mark aggregate (10). The patterns shown in (a), (b) and (c) are alignment marks (11) for transparent conductive films, alignment marks (12) for colored pixels for transmissive display, and alignment marks for photo spacers, respectively. (16) is represented.
The size of the alignment mark (11) for the transparent conductive film is about 4 mm in length and about 4 mm in width, and the size of the alignment mark (12) for a colored pixel for transmissive display to the spare space (19) for other alignment Is about 2 mm long and 2 mm wide.
The alignment mark assembly (10) is common to all items of the color filter, and is provided at the same time when a black matrix is formed on a glass substrate, and is used when forming a colored pixel, a transparent conductive film, a photo spacer, and the like. The corresponding alignment mark in the alignment mark assembly (10) is selected and used.
[0034]
FIG. 3 is an enlarged plan view showing one corner of one embodiment of the color filter for a liquid crystal display device according to the present invention. The color filter for a liquid crystal display device shown in FIG. 3 is at the stage where a black matrix, a colored pixel for transmissive display, and a transparent conductive film are formed on a glass substrate (30). This is a state in which a photo spacer is formed.
This color filter is a large-sized glass substrate (30) of about 650 mm × 850 mm with four diagonal 17 inch color filters (3) attached thereto. 3) represents the finished dimensions. (31B) is a frame portion, and (37) is a display portion. Colored pixels for transmissive display (not shown) are formed in the display section (37), and a transparent conductive film is formed on the display section (37) and the frame section (31B).
[0035]
(34) to (36) are marks used in the manufacturing process of the liquid crystal display device maker, such as the alignment mark (34) between the color filter and the TFT side substrate, and the cutting mark (35) of the liquid crystal display device. .
The alignment mark assembly (10) is provided at a fixed position on a peripheral portion (margin portion) (F) of a glass substrate (30) having a width of about 15 mm outside the color filter (3). The mark used by the liquid crystal display device manufacturer and the alignment mark assembly (10) used by the color filter manufacturer are also provided at the other three corners of the glass substrate (30).
[0036]
The fixed position where the alignment mark assembly (10) is provided is a position adjusted in advance with a liquid crystal display device maker, and once set, it becomes a position common to all items of the color filter.
Therefore, by providing the alignment mark assembly according to the present invention at a fixed position, there is no need for adjustment and mutual confirmation regarding marks between the liquid crystal display device maker and the color filter maker. Don't spend your time.
[0037]
Also, in the manufacturing process of the color filter manufacturer, an accompanying layer such as a colored pixel, a transparent conductive film, and a photo spacer is formed on a glass substrate on which an alignment mark assembly common to all items is provided at a fixed position. In this case, the corresponding alignment mark may be selected and used.
[0038]
【The invention's effect】
The present invention is an alignment mark aggregate in which each alignment mark for a colored pixel, a transparent conductive film, and an associated layer is assembled as an alignment mark, and includes a colored pixel, a transparent conductive film, and an associated layer. This is a color filter for a liquid crystal display device in which an alignment mark to be used by selecting a corresponding alignment mark in the alignment mark assembly at the time of formation is provided at a fixed position on the periphery of the glass substrate simultaneously with the formation of the black matrix. In addition to the basic functions, a new version of the color filter for liquid crystal display device which added various functions such as spacer function, alignment division function, high reliability function, combined transmission / reflection function and spectral characteristic adjustment function It does not require adjustment and mutual confirmation between the LCD display device manufacturer and the color filter manufacturer during production. That is, adjustment and mutual confirmation Without spending time corresponding to, can be produced by shortening the delivery time, furthermore, a color filter for a liquid crystal display device capable of producing without causing mistakes involving the setting of marks,.
[Brief description of the drawings]
FIG. 1 is an enlarged plan view showing an example of an alignment mark assembly according to the present invention.
FIGS. 2A, 2B, and 2C are plan views showing examples of alignment mark patterns constituting an alignment mark assembly.
FIG. 3 is an enlarged plan view showing one corner of one embodiment of a color filter for a liquid crystal display device according to the present invention.
FIG. 4 is a plan view schematically showing an example of a color filter used in the liquid crystal display device.
FIG. 5 is a cross-sectional view taken along line XX ′ of the color filter shown in FIG.
FIG. 6 is a plan view showing an example in which a 17-inch diagonal color filter is attached to a large-sized glass substrate on four sides and manufactured.
FIG. 7 is a partial cross-sectional view of a color filter for a liquid crystal display device on which a photo spacer (projection) is formed.
FIG. 8 is an explanatory diagram schematically showing a cross section of an LCD provided with an alignment control projection.
FIG. 9 is an explanatory diagram showing an example of a color filter forming an associated layer.
FIG. 10 is an explanatory view showing another example of a color filter forming an associated layer.
FIG. 11 is a cross-sectional view of an example of a color filter used in a transflective liquid crystal display device.
FIG. 12 is a cross-sectional view of another example of a color filter used in a transflective liquid crystal display device.
[Explanation of symbols]
3 Color filters 4, 7, 8 according to the present invention Color filters 10 Alignment mark aggregates 11, 95 according to the present invention Alignment marks 12 for transparent conductive films 12 Alignment marks 13 for colored pixels for transmissive display ... Positioning marks 14 and 97 for colored pixels for reflective display ... Positioning marks 15 for transparent parts ... Positioning marks 16 and 96 for protective layer (overcoat layer) ... Positioning marks 17 for photo spacers ... Orientation Alignment marks 18 and 19 for control projections Preliminary space 20 for other alignments TFT substrate 21 Liquid crystal molecules 22a, 22b and 23 Alignment control projections 30, 40 and 60 Glass substrates 31B and 41B Black matrix Frame parts 34, 91: alignment marks 35, 92 between the color filter and the TFT-side substrate: liquid crystal display device Cutting marks 37, 47 Display section 41 Black matrix 41A Black matrix section 42 Colored pixel 42Tr Colored pixel 42R for transmissive display Colored pixel 43 for reflective display Transparent conductive film 44 Photo spacer 45 Colored section 46: transparent portion 94: alignment mark F for colored pixel: peripheral portion of glass substrate

Claims (1)

In a color filter for a liquid crystal display device, a colored pixel, a transparent conductive film, and a transparent conductive film are used as alignment marks to be used when positioning and forming a colored pixel, a transparent conductive film, and an associated layer on a glass substrate on which a black matrix is formed. , And an alignment mark aggregate in which respective alignment marks for the associated layer are gathered, and the corresponding alignment mark in the alignment mark aggregate is formed when the colored pixel, the transparent conductive film, and the associated layer are formed. A color filter for a liquid crystal display device, wherein an alignment mark to be selected and used is provided at a fixed position on a peripheral portion of the glass substrate simultaneously with formation of a black matrix.

Images