JP2007156221A - Display and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display that can keep a uniform distance between substrates and achieve uniform display. <P>SOLUTION: In a display, the force by its weight added to a column spacer 67 in a center part apart from the outer circumference which is fixed by a sealing material 52 increases depending on the installation posture, for example, in a horizontal position. However, since a second column spacer 67B disposed in the center part has a large cross-sectional area, the shrinkage against added force can be reduced, and thereby, the distance between substrates can be uniformly maintained both in an outer peripheral part and in a center part, thus obtaining uniform display. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a large display and an electronic apparatus using the same.

With the thinning of the display, the demand for a large screen area is increasing, and the demand for a large display having a diagonal size of 40 inches is increasing.
In a thin display, a structure for controlling display between flat substrates facing each other, such as a liquid crystal display and a surface conduction electron-emitting device display, is often used. For example, a liquid crystal display performs display using the fact that the polarization state of light transmitted through the liquid crystal differs depending on the orientation of the liquid crystal. Specifically, the alignment of the liquid crystal is controlled by applying a voltage to an electrode provided on the opposite surface of the substrate, having liquid crystal sealed between the substrates. Here, the distance between the substrates facing each other is several μm to several tens μm, and the accuracy is required to be 0.05 μm or less for uniform display.
The distance between the substrates can be controlled by a spherical or fiber spacer. However, these spacers are easy to move and damage the electrodes, the alignment film, and the like provided on the substrate, and display defects are caused by the scratches.
In order to solve this problem, a method is known in which column-shaped spacers, so-called column spacers, are formed of resin and the distance between the substrates is controlled (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 11-287983 (Section 7, FIG. 4, paragraph number [0037])

  Column spacers are also required to have flexibility against external forces in order to improve the impact resistance of the display itself. Here, in a large display, the force applied to the substrate due to its own weight varies depending on the location depending on the installation posture. Therefore, the amount of expansion / contraction of the flexible column spacer differs depending on the location, the distance between the substrates changes, and a uniform display cannot be obtained.

  An object of the present invention is to provide a display capable of uniform display while maintaining a uniform distance between substrates.

  The display of the present invention comprises two substrates facing each other, a sealing material provided along an outer periphery between the substrates, and a column spacer disposed in a sealing region surrounded by the sealing material, Of the column spacers arranged on the outer periphery of the sealing region, the second column spacer having a cross-sectional area larger than the cross-sectional area of the first column spacer having the smallest cross-sectional area is at least more than the first column spacer. Is also arranged at the center of the sealing region.

According to the present invention, the force due to the own weight applied to the column spacer in the central portion at a distance from the outer periphery fixed by the sealing material is increased by the installation posture, for example, the flat placement posture, but the second force disposed in the central portion. Since the column spacer has a large cross-sectional area, the amount of expansion and contraction decreases with respect to the applied force. Therefore, the distance between the substrates is kept uniform between the outer peripheral portion and the central portion, and uniform display can be obtained.
Here, the central portion of the sealing region refers to a region near the center of the sealing region.

In the present invention, the shape of the sealing material has a rotationally symmetric axis perpendicular to the substrate, and the second column spacer is disposed at a rotationally symmetric position with respect to the rotationally symmetric axis. Is preferred.
In the present invention, since the second column spacers are arranged at rotationally symmetric positions in the sealing region, each second column spacer receives a force due to its own weight evenly. Accordingly, the amount of expansion / contraction of the second column spacer is reduced uniformly, and the distance between the substrates is kept uniform, and a more uniform display can be obtained.

In the present invention, the two substrates are a switching element substrate on which a switching element is formed and a counter substrate facing the switching element substrate, and the second column spacer is provided outside a display region, The cross-sectional area of the column spacer 2 is preferably smaller than the area of the region where the switching element is formed.
In the present invention, in addition to the above-described effects, the second column spacer has a cross-sectional area smaller than the area of the region where the largest switching element is formed among the regions formed outside the display region. Even if the spacer is arranged outside the display area, the influence on the display area, for example, a decrease in visibility, etc. is small.
Here, “outside the display area” refers to an area where display is actually performed by transmission and reflection of light outside the area where the switching elements and the like are formed.

In the present invention, it is preferable that liquid crystal is sealed in the sealing region.
According to the present invention, a display using liquid crystal in which display unevenness occurs due to a slight change in the distance between the substrates, and a uniform display can be obtained while maintaining the distance between the substrates.

An electronic apparatus according to the present invention includes the display described above.
According to the present invention, an electronic apparatus capable of obtaining the above-described effects can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic plan view of a liquid crystal display device 100 which is a display in the present embodiment, and FIG. 2 is a schematic cross-sectional view taken along the line HH ′ of FIG.
The liquid crystal display device 100 includes a TFT (Thin Film Transistor) element 30 as a switching element.
In each drawing used for the following description, each layer and each member have different scales so that each layer and each member can be recognized on the drawing.

  1 and 2, the liquid crystal display device 100 includes a TFT array substrate 10 as a switching element substrate on which TFT elements 30 are provided in an array, and a counter substrate 20. These substrates are bonded together by a sealing material 52 which is a photo-curable sealing material. The sealing material 52 is formed in a frame shape along the outer periphery between the TFT array substrate 10 and the counter substrate 20. The liquid crystal 50 is sealed and held in a sealing region 203 surrounded by the sealing material 52.

In FIG. 1, a parting 53 made of a light shielding material is formed inside the sealing material 52.
A data line driving circuit 201 and a mounting terminal 202 are formed along one side of the TFT array substrate 10 in a region outside the sealing material 52, and the scanning line driving circuit 204 is formed along two sides adjacent to the one side. Is formed. On the remaining side of the TFT array substrate 10, a plurality of wirings 205 for connecting the scanning line driving circuits 204 provided on both sides of the image display area are provided. In addition, an inter-substrate conductive material 206 for providing electrical continuity between the TFT array substrate 10 and the counter electrode 121 provided on the counter substrate 20 is disposed at a corner portion of the counter substrate 20.

Instead of forming the data line driving circuit 201 and the scanning line driving circuit 204 on the TFT array substrate 10, for example, a TAB (Tape Automated Bonding) substrate on which a driving LSI is mounted and a peripheral portion of the TFT array substrate 10 The terminal group formed in the above may be electrically and mechanically connected via an anisotropic conductive film.
Further, in the liquid crystal display device 100, the phase difference depends on the operation mode, that is, the operation mode such as the TN (Twisted Nematic) mode, the STN (Super Twisted Nematic) mode, or the normally white mode / normally black mode. A plate, a polarizing plate and the like are arranged in a predetermined direction (not shown).

FIG. 3 is an enlarged cross-sectional view schematically showing a cross section of the liquid crystal display device 100.
The liquid crystal display device 100 includes a color filter 13 on the counter substrate 20 in order to perform color display. The color filters of the red filter 13A, the green filter 13B, and the blue filter 13C are formed together with the protective film 18. A black matrix 9 that does not transmit light is formed between the red filter 13A, the green filter 13B, and the blue filter 13C.

  A counter electrode 121 is formed on the protective film 18 of the color filter 13, and an alignment film 162 is formed on the counter electrode 121. The opposite surface of the counter substrate 20 on which the color filter 13 is formed is provided with a polarizing plate 175.

  The TFT array substrate 10 includes a transparent glass substrate 170, a TFT element 30 formed on the glass substrate 170, an alignment film 172 formed on the glass substrate 170 and the TFT element 30, and the like. Yes. Further, a surface of the glass substrate 170 opposite to the surface on which the TFT element 30 is formed is provided with a polarizing plate 176.

The inter-substrate distance between the TFT array substrate 10 and the counter substrate 20 is controlled by a column spacer 67. Here, as compared with the thickness of the first column spacer 67A disposed closest to the sealing material 52, that is, on the outer periphery of the sealing region 203, the thickness of the second column spacer 67B disposed on the inner side is as follows. It is thicker and gradually thicker toward the center. Further, the arrangement location is formed in an area outside the display area corresponding to the black matrix 9.
The height of the column spacer 67 is 1 to 5 μm depending on the distance between the substrates, and the diameter is sequentially changed from 10 to 50 μm.
Note that the number of the column spacers 67 is an explanatory number and not an actual number.

FIG. 4 is a plan view schematically showing the arrangement of the column spacers 67. As in FIG. 3, the number and size of the column spacers 67 are for explanation, not the number and size actually used.
In FIG. 4, compared with the cross-sectional area of the first column spacer 67A having the smallest cross-sectional area disposed on the outer periphery of the sealing region 203 surrounded by the sealing material 52, the second cross-sectional area disposed inside the first column spacer 67A The column spacer 67B has a large cross-sectional area. The cross-sectional area of the second column spacer 67B is formed so as to increase gradually toward the center.
The second column spacers 67B having different sizes are disposed at rotationally symmetric positions with respect to the rotational symmetry axis Z perpendicular to the substrate of the frame shape of the sealing material 52.

Below, based on FIG. 5 and FIG. 6, the arrangement | positioning location of the column spacer 67 is demonstrated in detail.
FIG. 5 shows an equivalent circuit diagram of the liquid crystal display device 100.
In the sealing region 203 shown in FIG. 1, a plurality of pixels 100A are configured in a matrix as shown in FIG. 5, and a TFT element 30 is formed in each of these pixels 100A. A data line 6A for sending pixel signals S1, S2,... Sn to the TFT element 30 is electrically connected to the source of the TFT element 30. Pixel signals S1, S2,..., Sn may be sent in this order, or may be sent for each group to a plurality of adjacent data lines 6A. The scanning line 3 </ b> A is electrically connected to the gate of the TFT element 30. The scanning signals G1, G2,..., Gm are applied in this order in a pulsed manner to the scanning line 3A at a predetermined timing.

  The pixel electrode 19 is electrically connected to the drain of the TFT element 30, and by turning on the TFT element 30 for a predetermined time, the pixel signals S1, S2,. Write to the pixel at a predetermined timing. The pixel signals S1, S2,..., Sn written in the liquid crystal 50 through the pixel electrode 19 in this way are held for a certain period of time with the counter electrode 121 shown in FIG. In order to prevent the held pixel signals S1, S2,..., Sn from leaking, a storage capacitor 60 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 19 and the counter electrode 121. For example, the voltage between the pixel electrode 19 and the counter electrode 121 is held by the storage capacitor 60 for a time that is three orders of magnitude longer than the time when the source voltage is applied. Thereby, the charge retention characteristics are improved, and the liquid crystal display device 100 with a high contrast ratio can be realized.

FIG. 6 is an enlarged schematic plan view showing a portion including one TFT element 30 of the TFT array substrate 10.
As shown in FIG. 6, on the TFT array substrate 10 having the TFT elements 30, the gate wiring 12, the source wiring 16, the drain electrode 14, the gate electrode 11, and the drain electrode 14 are electrically connected. A pixel electrode 19 and a column spacer 67 are formed.
The gate wiring 12 is formed to extend in the X-axis direction, and a part thereof is formed to extend in the Y-axis direction. A part of the gate wiring 12 extending in the Y-axis direction is used as the gate electrode 11. Note that the width of the gate electrode 11 is narrower than the width of the gate wiring 12. A part of the source wiring 16 formed to extend in the Y-axis direction is formed to extend in the X-axis direction, and a part of the source wiring 16 is used as the source electrode 17.

In FIG. 6, the column spacer 67 is provided in a region where the TFT element 30 is formed, a region where the gate wiring 12 is formed, and a region where the source wiring is formed. These areas are areas that do not transmit light and are outside the display area. In FIG. 6, the region where the pixel electrode 19 is formed is the display region. The column spacer 67 may be provided for each element or may be provided for every plurality of elements. A plurality of elements may be provided in one element.
The cross-sectional area of the second column spacer 67B is smaller than the area of the region where the TFT element 30 is formed.

The material of the column spacer 67 is a resin capable of removing an unexposed portion with an alkaline developer, a (meth) acrylic resin containing maleic acid, a maleic resin, as an alkalized soluble resin that is a photosensitive resin composition for photolithography. Rosin resin, acrylic modified epoxy resin, and the like.
Further, as a method for manufacturing the column spacer 67, a photolithography method and a droplet discharge method can be used. The column spacer 67 may be formed on either side of the TFT array substrate 10 or the counter substrate 20.
For example, when forming the color filter 13 on the counter substrate 20 by the droplet discharge method, a bank is formed on the black matrix 9, and the color filters of the red filter 13A, the green filter 13B, and the blue filter 13C are discharged between the banks. Can be formed by law. At this time, the column spacer 67 can be formed on the bank by a droplet discharge method.

FIGS. 7A and 7B, FIGS. 8C and 8D, FIGS. 9E and 9F, and FIG. 10 are plan views showing other arrangement examples of the column spacer 67. FIG. These are arrangement examples, and are not limited to these arrangements.
In FIG. 7A, four second column spacers 67B are provided near the center of the sealing region 203. The four second column spacers 67B are arranged at rotationally symmetric positions with respect to the rotationally symmetric axis Z having the shape of the sealing material 52.
In FIG. 7B, the second column spacer 67B is disposed at one position at the rotational symmetry axis Z.

In FIG. 8C, the second column spacer 67 </ b> B is provided on the diagonal line of the frame-shaped sealing material 52.
In FIG. 8D, the second column spacer 67B is provided on a line that bisects the long side of the frame-shaped sealing material 52 and a line that bisects the short side.

In FIG. 9E, the second column spacer 67B is arranged in a rhombus shape near the middle between the outer periphery and the center of the sealing region 203.
In FIG. 9F, the second column spacer 67B is provided at the center of the sealing region 203.
The above arrangement of the second column spacer 67B is an example in which the second column spacer 67B is arranged at a position to be rotated with respect to the rotational symmetry axis Z.

  In FIG. 10, the second column spacer 67B has a second column spacer 67B having the largest cross-sectional area at the position of the rotational symmetry axis Z, and the cross-sectional area of the second column spacer 67B spirals toward the outer periphery. It arrange | positions so that it may become small sequentially.

  As shown in FIG. 10, the arrangement of the second column spacer 67B having a larger cross-sectional area than the first column spacer 67A closest to the sealing material 52 can be freely selected. It is more preferable to arrange it isotropically.

According to the first embodiment, there are the following effects.
(1) The force due to the self-weight applied to the column spacer 67 in the central portion at a distance from the outer periphery fixed by the sealing material 52 becomes larger depending on the installation posture, for example, the flat placement posture, but the second force disposed in the central portion. Since the column spacer 67B has a large cross-sectional area, the amount of expansion and contraction can be reduced with respect to the applied force. Therefore, the distance between the substrates can be kept uniform between the outer peripheral portion and the central portion, and a uniform display can be obtained.

  (2) Since the second column spacers 67B are disposed at rotationally symmetric positions in the sealing region 203, each second column spacer 67B receives a force due to its own weight evenly. Therefore, the expansion / contraction amount of the second column spacer 67B can be reduced uniformly, the distance between the substrates can be kept uniform, and a more uniform display can be obtained.

  (3) Since the cross-sectional area of the second column spacer 67B is smaller than the area of the region where the largest TFT element 30 is formed in the region formed outside the display region, the second column spacer 67B is out of the display region. Even if it arrange | positions, it can reduce the influence which it has on a display area, for example, the fall of visibility, etc.

  (4) With the liquid crystal display device 100 using the liquid crystal 50 in which display unevenness occurs due to slight changes in the inter-substrate distance, the inter-substrate distance is maintained and uniform display can be obtained.

  (5) In the method in which the liquid crystal 50 is dropped onto the center of the substrate and then the other substrate is bonded to seal the liquid crystal 50, the cross-sectional area of the column spacer 67 on the outer periphery is small. It spreads to the outer periphery without receiving resistance, and the liquid crystal sealing process can be facilitated.

(Second Embodiment)
Next, an electronic apparatus according to the present invention will be described based on a second embodiment.
The electronic device of the present embodiment is an electronic device including the liquid crystal display device 100 described in the first embodiment. A specific example of the electronic apparatus of this embodiment will be described.
FIG. 11 is a perspective view showing a large liquid crystal television 900.
In FIG. 11, a large liquid crystal television 900 includes a liquid crystal display unit 901 in which the liquid crystal display device 100 of the first embodiment is incorporated.

According to the second embodiment, the following effects can be obtained.
(6) A large-sized liquid crystal television 900 which is an electronic device that can achieve the above-described effects can be provided.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, the column spacer 67 may have any shape.
Further, it can be applied not only to the liquid crystal display device 100 but also to a surface conduction electron-emitting device display.

The best method for carrying out the present invention has been disclosed in the above description, but the present invention is not limited to this. That is, the present invention has been described mainly with reference to specific embodiments, but without departing from the scope of the technical idea and object of the present invention, the materials, processing time, Various other modifications can be made by those skilled in the art.
Accordingly, the descriptions of the materials disclosed above, the processing time, and the like are limited to those described for illustrative purposes in order to facilitate understanding of the present invention and are not intended to limit the present invention. Descriptions excluding some or all of the limitations such as processing time are included in the present invention.

1 is a schematic plan view of a liquid crystal display device according to a first embodiment of the present invention. 1 is a schematic cross-sectional view of a liquid crystal display device. The expanded sectional view which showed the liquid crystal display device typically. The top view which showed the column spacer arrangement | positioning typically. The equivalent circuit diagram of a liquid crystal display device. The schematic enlarged plan view which showed the part containing the TFT element of a TFT array substrate. The top view which showed the column spacer arrangement | positioning typically. The top view which showed the column spacer arrangement | positioning typically. The top view which showed the column spacer arrangement | positioning typically. The top view which showed the column spacer arrangement | positioning typically. The perspective view which shows the large sized liquid crystal television concerning 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... TFT array substrate as switching element substrate, 20 ... Counter substrate, 30 ... TFT element as switching element, 50 ... Liquid crystal, 52 ... Sealing material, 67 ... Column spacer, 67A ... First column spacer, 67B ... No. 2 column spacers, 100 ... a liquid crystal display device as a display, 203 ... a sealing region, 900 ... a large liquid crystal television as an electronic device.

Claims (5)

Two substrates facing each other;
A sealing material provided along the outer periphery between the substrates;
A column spacer disposed in a sealing region surrounded by the sealing material,
Of the column spacers arranged on the outer periphery of the sealing region, a second column spacer having a cross-sectional area larger than that of the first column spacer having the smallest cross-sectional area is at least the first column spacer. It is arrange | positioned rather than the center part of the said sealing area | region. The display of claim 1, wherein
The shape of the sealing material has an axis of rotational symmetry perpendicular to the substrate,
The display according to claim 1, wherein the second column spacer is disposed at a rotationally symmetric position with respect to the rotational symmetry axis. The display according to claim 1 or claim 2,
The two substrates are a switching element substrate on which a switching element is formed and an opposing substrate facing the switching element substrate,
The second column spacer is provided outside the display area,
The cross-sectional area of the second column spacer is smaller than the area of the region where the switching element is formed. In the display according to any one of claims 1 to 3,
A liquid crystal is sealed in the sealing region. An electronic apparatus comprising the display according to any one of claims 1 to 4.

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