JP2001194681A6 - Liquid crystal device and electronic device - Google Patents

Abstract

【Task】
Color layers R, G, and B of a color filter have a delta arrangement. A data line (212) for applying a voltage to the sub-pixels is connected to the pixel electrodes (234) of the sub-pixels corresponding to each color repeatedly in a certain order via the TFD (220), while 1 The pixel electrode (234) commonly connected to the data line (212) is arranged on the same side with respect to the data line (212). Thereby, the potential of the sub-pixel in the specific color is equally affected by the potential of the sub-pixel in the other color.
[Selection] Figure 1

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal device in which sub-pixels corresponding to three different colors are arranged in a delta shape, and an electronic apparatus having the liquid crystal device.
[0002]
[Background]
In recent years, liquid crystal devices have been widely used in electronic devices such as small computers, digital cameras, and mobile phones. In general, the liquid crystal device includes a pair of substrates facing each other with a liquid crystal interposed therebetween, and electrodes formed on opposing surfaces of the substrates. Furthermore, dot-like pixels are formed by these two electrodes and liquid crystal sandwiched between the electrodes, and are arranged in a matrix. Here, when a voltage is selectively applied between the electrodes forming the pixel, the orientation of the liquid crystal changes, and the amount of light passing through the liquid crystal is controlled to perform dot display.
[0003]
When performing color display in such a liquid crystal device, one pixel is divided into sub-pixels corresponding to the three primary colors R (red), G (green), and B (blue). They are arranged in a matrix with a predetermined pattern. Generally, coloring in the sub-pixel is performed by a color filter formed on one substrate.
[0004]
Here, in the liquid crystal device, as the color arrangement of the sub-pixels, that is, the arrangement of the colored layers in the color filter, the RGB stripe arrangement as shown in FIG. 15, the RGB mosaic arrangement as shown in FIG. An RGGB mosaic arrangement as shown in FIG. 1 and an RGB delta arrangement as shown in FIG. 18 are known. In each of these drawings, “R”, “G”, and “B” indicate colors colored by sub-pixels, specifically, “R” is red, “G” is green, “B” "Indicates blue, respectively.
[0005]
The RGB stripe arrangement shown in FIG. 15 is also called a trio arrangement and is suitable for applications such as a data display for displaying characters and straight lines, but has a lower resolution than other arrangements.
[0006]
In addition, since the RGB mosaic arrangement shown in FIG. 16 has a difference in display quality between the upward-sloping diagonal line and the upward-sloping diagonal line, diagonal noise occurs in the entire image. In particular, when the number of subpixels is small, the noise becomes significant.
[0007]
On the other hand, the RGGB mosaic arrangement shown in FIG. 17 is generally said to have high resolution because of the large number of “G” having high visibility, but the evaluation is not necessarily high in subjective evaluation experiments. Furthermore, when the viewing distance is short, the number of “B” and “R” is small, and the roughness of the image is conspicuous.
[0008]
The RGB delta arrangement shown in FIG. 18 has a horizontal resolution 1.5 times that of the RGB mosaic arrangement. In addition, since the diagonal component is inferior, it is said that there is difficulty in the contour of the image compared to the RGGB mosaic arrangement, but the evaluation is the highest in the subjective evaluation experiment.
[0009]
As described above, when the arrays are compared with the same density of sub-pixels, the RGB delta array that provides a high horizontal resolution is considered to be an array suitable for achieving high definition and high image quality.
[0010]
Next, in the RGB delta arrangement, the following two wiring patterns are known for connecting a sub-pixel and a conduction line (for example, a data line or a scanning line) for driving the sub-pixel. That is, as shown in FIG. 19, one data line 212 is connected to a pixel electrode 234 of a sub-pixel of two colors among three colors of RGB (hereinafter referred to as type 1), As shown in FIG. 20, a wiring pattern (hereinafter referred to as type 2) connected to the pixel electrode 234 of only one color sub-pixel is known. Here, the case where the conduction line is a data line is shown. In these drawings, a short line 220d connecting each data line 212 and each pixel electrode 234 indicates an active element such as a TFT (Thin Film Transistor) or a TFD (Thin Film Diode).
[0011]
[Problems to be solved by the invention]
By the way, in the type 1 wiring pattern (see FIG. 19), the potential fluctuation of the sub-pixel corresponding to one color among the two sub-pixels shared by a certain data line 212 changes to the other color. It is affected by the potential of the corresponding subpixel. For this reason, so-called vertical crosstalk occurs, and as a result, there is a problem that streak-like unevenness (straight unevenness) occurs in the display image and the display quality deteriorates.
[0012]
This problem can be solved by adopting a type 2 wiring pattern (see FIG. 20) in which only one color is assigned by one data line 212. However, in this type 2 wiring pattern, when the potential of the data line 212 adjacent to a certain subpixel varies, the potential of the subpixel also varies. For this reason, so-called horizontal crosstalk occurs, and as a result, a non-uniformity occurs in the display image, causing another problem that the display quality is deteriorated.
[0013]
Accordingly, an object of the present invention is to provide a liquid crystal device capable of preventing display image unevenness due to vertical crosstalk and display image unevenness due to horizontal crosstalk, thereby improving display quality, and An object of the present invention is to provide an electronic device having a liquid crystal device.
[0014]
Before disclosing the present invention, the above-mentioned stripe unevenness will be examined in detail.
[0015]
First, in the type 1 wiring pattern shown in FIG. 19, the non-uniformity of the display image caused by vertical crosstalk is specifically complementary to “R”, “G”, and “B”, respectively. When a single color pattern (solid pattern) of cyan, magenta, or yellow is displayed, light and dark are generated for each line.
[0016]
Here, as a liquid crystal device, a normally white mode that displays white (off) when no voltage is applied will be described as an example. For example, when displaying cyan, black (on), “ Since the “G” and “B” sub-pixels are white (off), it is necessary to write only to the R sub-pixel.
[0017]
In the type 1 wiring pattern, the data line 212 of (1) is connected to the pixel electrodes 234 of the sub-pixels “R” and “G”, and “G” is connected to the data line 212 of (2). ”And“ B ”are connected to the pixel electrodes 234 of the sub-pixels, and the data line 212 of (3) is connected to the pixel electrodes 234 of the sub-pixels of“ B ”and“ R ”.
[0018]
Since the “G” pixel electrode 234 located in the even row is connected only to the data line 212 of “1”, the “R” subpixel located in the odd row of the data line 212 of “1”. When writing is performed, the difference between the potential of the “G” sub-pixel connected to the data line 212 of (1) and the potential of the data line 212 of (1) increases. For this reason, the potential of the “G” sub-pixel in the even-numbered row is drawn to the write potential for the “R” sub-pixel as indicated by (1) in FIG. This is a type of vertical crosstalk.
[0019]
On the other hand, the pixel electrode 234 of “G” located in the odd row is connected only to the data line 212 of (2), and the sub-pixel of “R” is connected to the data line 212 of (2). Therefore, the difference between the potential of the “G” sub-pixel connected to the data line 212 of (2) and the potential of the data line 212 of (2) remains small. Therefore, the potential of the “G” sub-pixel is hardly affected by the write potential for the “R” sub-pixel, as indicated by (2) in FIG.
[0020]
As a result, the effective voltage value applied to the “G” sub-pixel in the even-numbered row is lower than the effective voltage value applied to the “G” sub-pixel in the odd-numbered row. This results in the phenomenon that the sub-pixel is bright and the odd-numbered “G” sub-pixel is dark. The same phenomenon also occurs for the “B” sub-pixel, as can be seen from (3) in FIG. 21. The even-numbered “B” sub-pixel is dark and the odd-numbered “B” sub-pixel is bright. Become.
[0021]
Eventually, light and dark differences occur every other line, causing uneven stripes. The same applies to the case of displaying yellow and magenta, and light and dark appear in the odd and even lines, resulting in uneven stripes.
[0022]
In FIG. 21, (1), (2), and (3) represent data lines 212 of (1), (2), and (3) in FIG. 19 when a cyan solid pattern is displayed. The horizontal axis represents the potential of the video signal corresponding to. Further, in this figure, the video signal is expressed by a voltage modulation method, but the concept is the same in a pulse width modulation (PWM) method which is a standard driving method of a liquid crystal device using TFD.
[0023]
The vertical crosstalk is caused by the fact that one data line 212 is connected to the pixel electrodes 234 of the sub-pixels of two colors. Therefore, if the type 2 wiring pattern shown in FIG. 20 is employed, such vertical crosstalk should be eliminated.
[0024]
However, this type 2 wiring pattern has another problem that streaks occur due to lateral crosstalk. This becomes prominent when complementary colors (ie, cyan, magenta, yellow) of “R”, “G”, and “B” are displayed. That is, the uneven stripe caused by the horizontal crosstalk in FIG. 20 is, for example, yellow in which the “B” sub-pixel is black (on) and the “R” and “G” sub-pixels are white (off). When displayed, the “G” subpixel located in the odd row is brighter than the “G” subpixel located in the even row, and the “R” subpixel located in the even row is odd. This is a phenomenon that it is brighter than the “R” sub-pixel located in the row.
[0025]
Here, when the present inventor paid attention to the wiring pattern, the uneven stripe caused by the lateral crosstalk is the data line (5) related to black writing (data connected to the sub-pixel of “B”). The sub-pixels surrounded by the line 212 (that is, the “G” sub-pixel located in the odd-numbered row and the “R” sub-pixel located in the even-numbered row) are bright and do not participate in black writing (4), (6) It was confirmed that the phenomenon was that the sub-pixels surrounded by the data line 212 of ▼ (that is, the “G” sub-pixel located in the even-numbered row and the “R” sub-pixel located in the odd-numbered row) were dark.
[0026]
When this phenomenon is observed macroscopically, since bright vertical lines (GRGR) and dark vertical lines (RGRG) appear alternately, they are visually recognized as vertical stripes. In the case of cyan display (“R” sub-pixel is black) by changing the display color and magenta display (“G” sub-pixel is black), the sub-pixel surrounded by the data lines involved in black writing It was also confirmed that the sub-pixels surrounded by the data lines not involved in black writing are dark, and the sub-pixels are dark. Depending on the pitch of the sub-pixels, the same phenomenon may be visually recognized as a horizontal stripe.
[0027]
Furthermore, in order to examine in detail, the present inventors measured the VT curve (voltage-transmittance characteristics) of the subpixel while changing the conditions of the peripheral subpixels. 22 and 23 show the measurement results. Of these, FIG. 22 shows the off (white) waveform measured in the “G” sub-pixel located in the even-numbered row, and FIG. 23 similarly shows the “G” sub-pixel located in the even-numbered row. The measured ON (black) waveform is shown, and both are ON (black) / OFF (white) in the peripheral “R” and “B” subpixels with respect to the “G” subpixel to be measured. This is a measurement of the state of the waveform change when.
[0028]
As can be seen from the VT curves shown in these figures, the voltage applied to the even-numbered “G” sub-pixel is black for the “R” sub-pixel regardless of the black and white color of the “B” sub-pixel. In this case, while shifting to the high voltage side, the waveform tends to shift to the low voltage side when the “R” sub-pixel is white. This is particularly noticeable in the off (white) waveform in FIG. 22, and such a shift in optical characteristics agrees well with the phenomenon observed with the naked eye. When comparing V50 (that is, the voltage at which the transmittance is 50%) under the conditions of R: white / B: white and R: black / B: black, the difference of 1.4 V is shown in FIG. There is a difference of 1.8V in FIG.
[0029]
From the above measurement results, the wiring for driving the sub-pixel corresponding to a certain color (assuming “R” sub-pixel) is the periphery of the adjacent sub-pixel (assuming “G” sub-pixel). It is presumed that a shift in the voltage applied to the sub-pixel occurs as a result of the parasitic capacitance generated by surrounding the substrate and the effective capacitance ratio fluctuating.
[0030]
For example, in FIG. 22 and FIG. 23, the reason why the behavior of the VT curve in the “G” sub-pixel in the even-numbered row is dominated by the lighting state of the “R” sub-pixel is Since the data line 212 of (6) connected exclusively to the “R” sub-pixel is capacitively coupled, the voltage fluctuation affects the voltage applied to the “G” sub-pixel. It is. Thus, since the brightness of a subpixel is affected by the wiring adjacent to the subpixel in the row direction, this phenomenon is lateral crosstalk.
[0031]
In a liquid crystal device using a TFD as an active element, when a wiring on the element side is a data line and an electrode on the counter substrate side (that is, the color filter side) is a scanning line, a data line for driving a subpixel is The data line for driving sub-pixels of other colors is present only on the right or left side of the pixel electrode of the sub-pixel and on the other side. Therefore, it can be said that the horizontal crosstalk is not limited to the delta arrangement, but can occur in other arrangements such as mosaics and stripes as well.
[0032]
In fact, in a liquid crystal device having the same number of subpixels and the same subpixel pitch and in which only the color arrangement of the subpixels is a mosaic arrangement, when measuring the VT curve in units of subpixels, It has been clearly confirmed by the present inventors that a voltage shift occurs as in FIG. However, the phenomenon of being visually recognized as serious unevenness in the delta arrangement does not cause a problem in the mosaic arrangement. This is because in the case of a mosaic arrangement, there is no distinction between odd rows and even rows and the whole is uniformly affected. This is why the transverse crosstalk becomes apparent as a problem specific to the delta arrangement.
[0033]
Conversely, the horizontal crosstalk seen in the type 2 wiring pattern in the delta arrangement exists basically regardless of the subpixel color arrangement, but the effect is uniform for all color subpixels. If this is the case, it is considered that this is not a display defect. Therefore, it is considered that an important point is that the color of the sub-pixel driven by the wiring coupled to the sub-pixel of a certain color does not change for each row. However, even if the influence of the horizontal crosstalk is uniform for all the sub-pixels, the type 1 wiring pattern that may cause the vertical crosstalk cannot be employed as described above.
[0034]
From such circumstances, the present inventors examined a wiring pattern in which three colors of “R”, “G”, and “B” are connected to one data line as a new attempt in the delta arrangement. As such a wiring pattern, three types of type 3 shown in FIG. 24, type 4 shown in FIG. 25, and type 5 shown in FIG. 1 were assumed. Then, the inventor evaluated the degree of influence of the coupling of the wiring on the sub-pixel for these three types of wiring patterns. This evaluation result is shown in FIG.
[0035]
In this evaluation result, the degree of influence when the half of the four sides of the pixel electrode is surrounded by “2” in the focused sub-pixel is “2”, and the degree of influence when surrounded by the L-shape is “1.5”. The degree of influence in the case of only a straight line (one side) is “1”, and the influence from the data line (left wiring) located on the left side with respect to the pixel electrode of the focused sub-pixel is minus, and the data located on the right side. The influence from the line (right wiring) was considered positive. Further, not only the difference (range) between the minimum value and the maximum value in the influence level but also the maximum change amount between adjacent scanning lines was considered.
[0036]
Here, in the type 3 wiring pattern shown in FIG. 24 and the type 4 wiring pattern shown in FIG. 25, the color of the sub-pixel driven by the data line coupled to the sub-pixel of a certain color has six rows. Since they are switched every time, it is not preferable in terms of lateral crosstalk as in the case of the wiring pattern of type 2 (see FIG. 19).
[0037]
Therefore, it is considered that the type 5 wiring pattern shown in FIG. 1 is most desirable from the viewpoint of inhibiting the occurrence of crosstalk in consideration of the evaluation result of the coupling influence degree.
[0038]
[Means for Solving the Problems]
Accordingly, the first invention of the present invention is a liquid crystal device in which subpixels corresponding to three different colors are arranged in a triangle, and a conductive line for applying a voltage to these subpixels corresponds to the three colors. The pixel electrode is connected to the pixel electrode of the sub-pixel repeatedly in a certain order, while the pixel electrode commonly connected to one conduction line is arranged on the same side with respect to the conduction line. . According to this configuration, no matter which row of sub-pixels is concerned, each sub-pixel is connected to a conduction line located on the other side only by being connected by a conduction line located on one side. Do not ring. For this reason, when the subpixels of the same color existing in each row are viewed, the colors of the subpixels driven by the data lines coupled to those subpixels are the same across the rows. Therefore, since the influence of the horizontal crosstalk is uniform for all the sub-pixels, it is possible to obtain a good display quality that does not cause unevenness.
[0039]
Here, in the first invention of the present case, since the form surrounding the pixel electrode by the conductive line is different for each row, if the distance between the conductive line and the pixel electrode adjacent to the conductive line is the same for each row, Coupling capacity varies from line to line. Therefore, in the first invention, the conductive line is a data line, and the distance between the data line and the pixel is increased as the length of the portion along the pixel electrode of the data line is increased. Or, a configuration in which the data line is thin is desirable. According to this configuration, since the coupling capacitance between the data line and the pixel electrode adjacent to the data line is made uniform over each row, it is possible to achieve a good display without unevenness.
[0040]
In the first aspect of the invention, the conductive line has a pattern in which one cycle is a multiple of 6 because the number of colors used in the so-called delta arrangement is “3”. A connected configuration is desirable.
[0041]
Further, in the first invention, the conductive line is preferably connected to the pixel electrode via an active element, and the active element is a thin film diode made of a conductor / insulator / conductor. An element is desirable. Such an active element can electrically separate a sub-pixel to be turned on from a sub-pixel to be turned off, and a thin film diode in which it is difficult to form a storage capacitor in parallel with the pixel electrode is used as the active element. However, a uniform display image can be obtained.
[0042]
Next, in order to achieve the above object, the second invention of the present application is an electronic apparatus having a liquid crystal device in which subpixels corresponding to three different colors are arranged in a triangle, and applies a voltage to these subpixels. The conductive line for connecting to the pixel electrodes corresponding to the sub-pixels corresponding to the three colors is repeatedly connected in a certain order, while the pixel electrode commonly connected to one conductive line is connected to the conductive line. It is characterized by being arranged on the same side. According to this electronic apparatus, it is possible to obtain a good display without streaking.
[0043]
Subsequently, in order to achieve the above object, the third invention of the present application is a liquid crystal device in which subpixels corresponding to three different colors are arranged in a triangle, and a conduction line for applying a voltage to these subpixels. Is characterized in that the parasitic capacitance with the pixel electrode of the sub-pixel is equalized over each sub-pixel.
[0044]
Here, in order to make the parasitic capacitance with the pixel electrode of the subpixel uniform over each subpixel, first, the periphery of the pixel electrode is surrounded by a conductive line connected to the pixel electrode. Can be considered. According to this configuration, since the data line coupled to the pixel electrode is only the data line connected to the pixel electrode, it is considered most desirable in view of only equalization of parasitic capacitance.
[0045]
Also, in order to make the parasitic capacitance with the pixel electrode of the subpixel uniform over each subpixel, secondly, in the pixel electrode, the periphery other than the side facing the adjacent conduction line is connected to the pixel electrode. The structure surrounded by the substantially same width by the conduction | electrical_connection line to be considered can be considered. According to this configuration, one side of the pixel electrode is coupled to an adjacent conduction line, which is advantageous in terms of reducing short circuit and improving the aperture ratio in the manufacturing process.
[0046]
Furthermore, in the third aspect of the invention, it is preferable that the conductive line is connected to the pixel electrode in a pattern in which a multiple of 6 is one cycle. This is because the number of colors used in the so-called delta arrangement is “3” as in the first invention.
[0047]
In the third invention, as in the first invention, the conductive line is preferably connected to the pixel electrode via an active element, and the active element is a conductor. A thin film diode element made of / insulator / conductor is desirable.
[0048]
In order to achieve the above object, the fourth aspect of the present invention is an electronic apparatus including a liquid crystal device in which subpixels corresponding to three different colors are arranged in a triangle, and applies a voltage to these subpixels. The conductive line is characterized in that the parasitic capacitance with the pixel electrode of the sub-pixel is equalized over each sub-pixel. According to this electronic apparatus, it is possible to obtain a good display without streaking.
[0049]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described for each embodiment with reference to the drawings.
[0050]
<First Embodiment> First, a liquid crystal device according to a first embodiment of the present invention will be described with reference to FIGS. Here, FIG. 3 is a perspective view showing the configuration of the liquid crystal device according to the present embodiment, and FIG. 4 is a cross-sectional view showing the configuration of the liquid crystal device.
[0051]
As shown in these drawings, the liquid crystal device 100 includes a pair of translucent substrates 200 and 300. Among these, the substrate 200 is an element side substrate on which an active element is formed, and the substrate 300 is a counter substrate facing the element side substrate 200.
[0052]
Among these, on the inner surface of the element-side substrate 200, as shown in FIG. 4, a plurality of data lines 212, a plurality of TFDs 220 connected to the data lines 212, and the TFDs 220 are in a one-to-one relationship. The pixel electrode 234 connected to the pixel electrode 234 is formed by, for example, a photolithography method or the like. Here, each data line 212 is formed so as to extend in a direction perpendicular to the paper surface in FIG. 4, while the TFD 220 and the pixel electrode 234 are arranged in a dot matrix. An alignment film 214 subjected to uniaxial alignment processing, for example, rubbing processing, is formed on the surface of the pixel electrode 234 and the like.
[0053]
On the other hand, a color filter 308 is formed on the inner surface of the counter substrate 300 to constitute a colored layer of three colors “R”, “G”, and “B”. Note that a black matrix 309 is formed in the gap between the colored layers of these three colors to block incident light from the gap between the colored layers. An overcoat layer 310 is formed on the surfaces of the color filter 308 and the black matrix 309, and a counter electrode 312 functioning as a scanning line is formed on the surface in a direction perpendicular to the data lines 212. Note that the overcoat layer 310 is provided for the purpose of improving the smoothness of the color filter 308 and the black matrix 309 and preventing the counter electrode 312 from being disconnected. Further, an alignment film 314 that has been subjected to a rubbing process is formed on the surface of the counter electrode 312. The alignment films 214 and 314 are generally formed of polyimide or the like.
[0054]
The element-side substrate 200 and the counter substrate 300 are bonded to each other with a certain gap by a sealing material 104 including a spacer (not shown), and the liquid crystal 105 is sealed in the gap. . A polarizing plate 317 having an optical axis corresponding to the rubbing direction to the alignment film 214 is attached to the outer surface of the element side substrate 200. Similarly, a polarizing plate 217 having an optical axis corresponding to the rubbing direction to the alignment film 314 is attached to the outer surface of the counter substrate 300.
[0055]
The liquid crystal device 100 is applied with a liquid crystal driving IC (driver) 250 directly on the surface of the element side substrate 200 by applying a COG (Chip On Glass) technique. As a result, each output terminal of the liquid crystal driving IC 250 is connected to each data line 212. Similarly, the liquid crystal driving 350 is directly mounted on the surface of the counter substrate 300, and each output terminal of the liquid crystal driving IC 350 is connected to each of the counter electrodes 212 serving as scanning lines.
[0056]
The configuration is not limited to the COG technology, and the IC chip and the liquid crystal device may be connected using other technologies. For example, a TAB (Tape Automated Bonding) technique may be used to electrically connect a TCP (Tape Carrier Package) in which an IC chip is bonded on an FPC (Flexible Printed Circuit) to the liquid crystal device. Further, COB (Chip On Board) technology for bonding an IC chip to a hard substrate may be used.
[0057]
Now, on the inner surface of the element-side substrate 200, the TFD 220 and the pixel electrodes 234 are arranged in a dot matrix as shown in FIG. In particular, the pixel electrodes 234 are arranged with a shift of 0.5 pitch for each row (that is, in the horizontal direction). On the other hand, the counter electrode 312 formed on the inner surface of the counter substrate 300 is in a positional relationship facing one row of the pixel electrodes 234 formed on the element side substrate 200, and further, the color formed on the counter substrate 300. Of the filter 308, a colored layer for one color is provided corresponding to an intersection region between the pixel electrode 234 and the counter electrode 312. Therefore, one subpixel is composed of the pixel electrode 234, the counter electrode 312, the liquid crystal 105 sandwiched therebetween, and a color layer for one color in the color filter 308.
[0058]
Here, in FIG. 1, “R” attached to each pixel electrode 234 indicates that a colored layer that transmits red light is arranged in the color filter 308 formed on the counter substrate 300 facing the pixel electrode 234. Show. Similarly, “G” indicates that a colored layer that transmits green light is disposed, and “B” indicates that a colored layer that transmits blue light is disposed. In particular, in the present embodiment, each colored layer of “R”, “G”, and “B” is located at the apex of a triangle, that is, a delta, and has an RGB delta arrangement.
[0059]
Furthermore, in this embodiment, the type 5 shown in FIG. 1 is adopted as the wiring pattern. That is, one data line 212 is repeatedly connected to the pixel electrodes 234 of the sub-pixels corresponding to the three colors “R”, “G”, and “B” through the TFD 220 in a certain order, The pixel electrode 234 commonly connected to one data line 212 is disposed on the same side (left side in FIG. 1) when viewed from the data line 212. This arrangement is common to all the data lines 212. In this embodiment, the distance between the pixel electrode 234 of the sub-pixel and the data line 212 located on the left side is the same for each row as shown in FIG. Specifically, the distance between the pixel electrode 234 and the data line is S3 when the data line 212 is located along only one side of the pixel electrode 234, and the data line 234 makes the pixel electrode 234 L-shaped. S1 = S2 = S3, and S1 = S2 = S3 is established when S2 is set to surround the pixel electrode 234 and S1 is set when the data line 234 surrounds half of the periphery of the pixel electrode 234.
[0060]
In the liquid crystal device 100 configured as described above, when the liquid crystal driving ICs 250 and 350 are activated, an on voltage or an off voltage is applied between the pixel electrode 234 and the counter electrode 312 in the selected subpixel. By such voltage control, the alignment state of the liquid crystal 105 is controlled for each sub-pixel. Based on this orientation control, the light passing through the sub-pixels of a specific color is modulated, so that images such as letters, numbers, and patterns are displayed in color.
[0061]
Further, in the liquid crystal device 100 of the present embodiment, since the color filter arrangement is an RGB delta arrangement, a higher horizontal resolution can be obtained compared to the RGB stripe arrangement, the RGB mosaic arrangement, and the RGGB mosaic arrangement. As a result, high-definition and high-quality liquid crystal display can be performed. Furthermore, in the present embodiment, a wiring pattern in which one data line 212 drives sub-pixels for three colors is adopted, so that vertical crosstalk in the type 1 wiring pattern (see FIG. 19) is suppressed. As a result, deterioration in display image quality due to this is avoided.
[0062]
In addition, in this embodiment, regardless of the row of subpixels, the subpixels are always connected to the data line 212 located on the right side, and each subpixel can only be coupled to the conduction line located on the opposite left side. Do not ring. For this reason, when the subpixels of the same color are viewed in each row, the colors of the subpixels driven by the data line 212 coupled to those subpixels are the same across the rows. Therefore, since the influence of the crosstalk exerted on the subpixels of each color in each row is uniform for all the subpixels, it is possible to obtain a good display quality that does not cause unevenness.
[0063]
<Second Embodiment> Now, in the first embodiment described above, the data line 212 surrounds the pixel electrode 234 as shown in FIG. 1 or FIG. (2) When the data line 212 surrounds the pixel electrode 234 in an L shape, and (3) When the data line 212 surrounds about one-half of the periphery of the pixel electrode 234 There are three types.
[0064]
Here, in the case of (3) in which the data line 212 surrounds about one-half of the periphery of the pixel electrode 234, the coupling capacitance between the data line 212 and the pixel electrode 234 increases, so that the potential fluctuation of the data line 212 changes. Also, the influence on the potential of the sub-pixel located on the right side is large. On the other hand, in the case of (1) in which the data line 212 is located along only one side of the pixel electrode 234, the coupling capacitance between the data line 212 and the pixel electrode 234 becomes small, so that the potential fluctuation of the data line 212 is reduced. The influence on the potential of the sub-pixel located on the right side is small. As a result, there is a difference in the influence on the potential of the sub-pixel depending on the form in which the data line 212 surrounds the pixel electrode 234. Therefore, there is a possibility that the display quality is deteriorated when S1 = S2 = S3 as in the first embodiment. is there.
[0065]
In order to avoid this, in the second embodiment of the present invention, S1>S2> S3 is set as shown in FIG. That is, when the data line 212 is located along only one side of the pixel electrode 234, the distance S3 of (1) is set small, and then the data line 212 surrounds about ½ of the periphery of the pixel electrode 234. When the distance S1 of 3 is set large, and the data line 212 surrounds the pixel electrode 234 in an L shape, the distance S2 of (2) is set to an intermediate size between them.
[0066]
According to this configuration, since the parasitic capacitance generated between the pixel electrode 234 and the data line 212 located on the left side of the pixel electrode 234 can be made equal for each row, the display quality is different for each sub-pixel due to the difference in parasitic capacitance. It is possible to prevent variation. Note that the same effect can be obtained by reducing the width of the surrounding data line 212 as the length of the data line 212 along the pixel electrode 212 becomes longer.
[0067]
<Third Embodiment> Next, a liquid crystal device according to a third embodiment of the present invention will be described. The liquid crystal device according to the third embodiment is the same as the first embodiment described above in the configuration shown in FIGS. 3 and 4, but differs in the layout of the element-side substrate 200. Therefore, this difference will be mainly described. FIG. 7 is a plan view showing the layout of the element substrate 200 in this liquid crystal device.
[0068]
As shown in this figure, the pixel electrodes 234 corresponding to the colors “R”, “G”, and “B” have an RGB delta arrangement as in the first embodiment. For example, the pixel electrodes 234 belonging to the A row are arranged so as to be shifted by 0.5 pitches in the row direction (X direction in the drawing) from the pixel electrodes 234 belonging to the adjacent B row.
[0069]
On the other hand, after a certain data line 212x proceeds from the R pixel located in the A row to the R pixel located in the D row in the figure in the lower left direction, this time the R pixel located in the A row. Continue down to the right. In this way, the data line 212x extends in the column direction in a folded pattern with six pixels extending from A to F rows as one cycle, and is shared by one column of the pixel electrodes 234 from a macro view. Here, the data line 212x surrounds the periphery of the shared pixel electrode 234 for each pixel electrode 234, and is connected to the pixel electrode 234 via the TFD 220.
[0070]
Here, the configuration of one sub-pixel will be described by taking as an example the one connected to the data line 212x and positioned in the B row or the C row. FIG. 8A is a plan view showing the layout of the one subpixel, and FIG. 8B is a cross-sectional view taken along the line AA. As shown in these drawings, the TFD 220 includes a first TFD 220a and a second TFD 220b. The element-side substrate 200, an insulating film 201 formed on the surface, a first metal film 222, An oxide film 224, which is an insulator formed on the surface by anodization, and second metal films 226a, 226b formed on the surface and spaced apart from each other are formed. The second metal film 226a becomes the data line 212x as it is, while the second metal film 226b is connected to the pixel electrode 234.
[0071]
The first TFD 220a is, in order from the data line 212x, the second metal film 226a / oxide film 224 / first metal film 222 to form a metal / insulator / metal sandwich structure. It will have switching characteristics. On the other hand, the second TFD 220b becomes the first metal film 222 / oxide film 224 / second metal film 226b when viewed in order from the data line 212x, and has the diode switching characteristics opposite to the first TFD 220a. It will be. Here, since both are in the form of two diodes connected in series in opposite directions, the current-voltage nonlinear characteristics are symmetric in both positive and negative directions compared to the case where one TFD is used. It will be.
[0072]
The cross section of the data line 212x is the first metal film 222, the oxide film 224, and the second metal film 226a, but the terminal connected to the data line 212x is only on the uppermost second metal film 226a. Since they are connected, the data line 212x does not function as a TFD.
[0073]
The substrate 200 itself has insulating properties and transparency, and is made of, for example, glass or plastic. Here, the reason why the insulating film 201 is provided is to prevent the first metal film 222 from being peeled off from the base by heat treatment after the deposition of the first metal film 222 and to diffuse the impurities into the first metal film 222. This is to prevent it from happening. Therefore, the insulating film 201 can be omitted when these do not cause a problem. The pixel electrode 234 is formed from a transparent conductive film such as ITO (Indium Tin Oxide) when used as a transmission type, and is formed from a metal film having a high reflectance such as aluminum or silver when used as a reflection type. The
[0074]
Further, the same applies to the pixels located in the E row or the F row except that the surrounding portion of the data line 212x is symmetric, and the surrounding portion of the data line 212 is the upper half of the pixel located in the A row or the D row. Or the same except that only the lower half is symmetric.
[0075]
Next, a manufacturing process of such an element side substrate 200 will be described focusing on the TFD 220. First, as illustrated in FIG. 9A, the insulating film 201 is formed on the upper surface of the substrate 200. The insulating film 201 is made of, for example, tantalum oxide, and is formed by a method of thermally oxidizing a tantalum film deposited by a sputtering method, a sputtering using a target made of tantalum oxide, or a co-sputtering method. As described above, the insulating film 201 is provided mainly for the purpose of improving the adhesion of the first metal film 222 and preventing the diffusion of impurities from the substrate 200. About 50 to 200 nm is sufficient.
[0076]
Next, as shown in FIG. 2B, a first metal film 222 is formed on the upper surface of the insulating film 201. The composition of the first metal film 222 is made of, for example, tantalum alone or a tantalum alloy. When a tantalum alloy is used, an element belonging to Groups 6 to 8 in the periodic table such as tungsten, chromium, molybdenum, rhenium, yttrium, lanthanum, dysprosium, or the like may be added to tantalum as a main component. . In addition, as an element to add, tungsten is preferable and the content rate is desirably 0.1 to 6% by weight, for example.
[0077]
The first metal film 222 can be formed by a sputtering method, an electron beam evaporation method, or the like. When the first metal film 222 made of a tantalum alloy is formed, a sputtering method using a mixed target or a co-sputtering method can be used. Or electron beam evaporation. Note that a suitable value for the thickness of the first metal film 222 is selected depending on the use of the TFD 220, and is usually about 100 to 500 nm.
[0078]
Then, as shown in FIG. 3C, the first metal film 222 is patterned by a commonly used photolithography and etching technique.
[0079]
Subsequently, an oxide film 224 is formed on the surface of the first metal film 222 as shown in FIG. Specifically, the surface of the first metal film 222 is formed by being oxidized by an anodic oxidation method. At this time, the surface of the portion serving as the basis of the data line 212x is simultaneously oxidized to form an oxide film 224. A preferable value of the thickness of the oxide film 224 is selected depending on the application, and is about 10 to 35 nm, for example, which is half that in the case of using one TFD for one pixel. Although the chemical conversion liquid used by anodization is not specifically limited, For example, 0.01-0.1 weight% citric acid aqueous solution can be used.
[0080]
Next, as shown in FIG. 5 (5), a second metal film 226 is formed. The second metal film 226 is made of, for example, chromium, aluminum, titanium, molybdenum, or the like, and is formed by being deposited by a sputtering method or the like. The film thickness of the second metal film 226 is, for example, about 50 to 300 nm.
[0081]
Subsequently, as shown in FIG. 10 (6), the second metal film 226 is patterned by a commonly used photolithography and etching technique. Thus, the second metal films 226a and 226b in the first and second TFDs are formed apart from each other, and the uppermost layer in the data line 212x is also covered with the second metal film 226.
[0082]
Next, as shown in FIG. 7 (7), a conductive film to be the pixel electrode 234 is formed. This conductive film is preferably ITO for a transmissive liquid crystal device, and aluminum or the like for a reflective liquid crystal device, both of which are formed by depositing with a film thickness of 30 to 200 nm by sputtering or the like. The
[0083]
Subsequently, as shown in FIG. 8 (8), the conductive film is patterned by commonly used photolithography and etching techniques to form the pixel electrode 234.
As shown in FIG. 9 (9), the wavy line portion 229 of the oxide film 224 branched from the data line 212x is generally used together with the first metal film 222 which is the basis thereof. Removed by existing photolithography and etching techniques. As a result, the first metal film 222 shared by the first and second TFDs is electrically separated from the first metal film 222 which is the lowermost layer of the data line 212x.
[0085]
Through such a process, the TFD 220 including the first TFD 220a and the second TFD 220b is formed on the substrate 200 together with the pixel electrodes 234 in a delta arrangement.
[0086]
In addition, about the manufacturing process of such TFD, it is not restricted to the order of the said process. For example, immediately after the oxide film 224 is formed on the surface of the first metal film 222 by the process in FIG. 9 (4), it is separated from the data line 212x by the process in FIG. 10 (9). It is also possible to execute the step (5) and the steps (6) to (8) in FIG.
[0087]
In the element-side substrate 200 configured in this way, the counter electrode (scanning line) that intersects the pixel electrode 234 and extends in the row direction, or the pixel electrode 234 is formed, as in the first embodiment. The counter substrate 300 on which the corresponding color filters and the like are formed is bonded with a sealing material while maintaining a certain gap (gap). Further, for example, a TN (Twisted Nematic) type liquid crystal is provided in this closed space. Is finally formed as a liquid crystal device.
[0088]
In the liquid crystal device according to the third embodiment, since the periphery of the pixel electrode 234 connected to the data line 212x is surrounded by the data line 212x itself, the adjacent data line 212 (x-1) or 212 (x + 1) The influence of coupling due to is eliminated. That is, only the coupling with its own data line 212x becomes a problem. The same applies to the pixel electrodes 234 connected to the adjacent data lines 212 (x−1) and 212 (x + 1). Therefore, according to such a liquid crystal device, since the parasitic capacitances of the sub-pixels positioned in the A-th to F-th are equal to each other, it is possible to make the display image uniform.
[0089]
<Fourth Embodiment> Next, a liquid crystal device according to a fourth embodiment of the present invention will be described.
[0090]
In the third embodiment described above, since the periphery of the pixel electrode 234 is surrounded by the data line itself connected thereto, the coupling capacitance due to the adjacent data line does not matter. For this reason, it can be said that it is excellent in the point of the uniformization of a display image. However, as shown in FIG. 8A, between the pixel electrodes 234 adjacent to each other, there are two data lines, specifically, the line L1 of the data lines 212x and the data line 212 (x + 1) adjacent thereto. Of the first metal film 222 and the patterning process of the second metal film 226, the possibility of short-circuiting increases, and the area occupied by the pixel electrode 234 The ratio (aperture ratio) of the screen decreases and the entire screen becomes dark.
[0091]
Therefore, the fourth embodiment will be described in which the parasitic capacitances of the pixel electrodes located in each row are made equal, and the problems of short circuit and aperture ratio in the third embodiment are solved.
[0092]
FIG. 11 is a plan view showing the layout of the element substrate 200 in this liquid crystal device. As shown in this figure, the pixel electrodes 234 corresponding to the colors “R”, “G”, and “B” have the same RGB delta arrangement as in the first and third embodiments. This is different from the third embodiment in that not all the periphery of the pixel electrode is surrounded by the data lines, but only three sides other than the side facing the adjacent data line are surrounded by the data lines having the same width. .
[0093]
Here, the configuration of one sub-pixel will be described by taking as an example the one connected to the data line 212x and positioned in the B row or the C row. FIG. 12A is a plan view showing the layout for one sub-pixel.
[0094]
As shown in this figure, in one sub-pixel in the second embodiment, the line L1 and the region M1 in FIG. 8A are deleted, and the pixel electrode 234 is located at the portion where the line L1 was present as indicated by the arrow. The configuration has been expanded to. Therefore, since only the adjacent data line (line L2) is disposed between the adjacent pixel electrodes 234, the possibility of a short circuit in the patterning process is reduced, while the interval between the sub-pixels is maintained. In this state, the area of the pixel electrode 234 is expanded, so that the aperture ratio is improved.
[0095]
By the way, the deletion of the region M1 is not directly related to the point of preventing a short circuit and the point of improving the aperture ratio. However, if this area M1 is not deleted, the width of the data line 212 surrounding the pixel electrode 234 will not be uniform. Further, this area M1 is, for example, a sub-row of B row or C row as shown in FIG. 12A. Unlike the pixel and the sub-pixel of the D row as shown in FIG. 12B, the pixel is different for each row, so that the parasitic capacitance is also different for each row. Therefore, the area M1 is deleted.
[0096]
With such a configuration, in the pixel electrode 234 located in each row, the three sides are equally surrounded by the data line having the same width, and only the other side is capacitively coupled to the adjacent data line. The capacity becomes equal to each other. For this reason, according to the liquid crystal device according to the fourth embodiment, it is possible to make the display image uniform while preventing a short circuit and a decrease in the aperture ratio.
[0097]
In each of the liquid crystal devices according to the third and fourth embodiments, the TFD 220 is connected to the data line side. On the contrary, the TFD 220 is connected to the scanning line side. But the same thing.
[0098]
In each of the liquid crystal devices according to the third and fourth embodiments, the TFD 220 is composed of the first TFD 220a and the second TFD 220b connected in series in opposite directions. Of course, it may be configured.
[0099]
Furthermore, in the liquid crystal device according to the embodiment, the second metal film 226 and the pixel electrode 234 are both made of different metal films, but the second metal film and the pixel electrode are made of an ITO film, an aluminum film, or the like. You may comprise from the same electrically conductive film. According to such a configuration, there is an advantage that the second metal film 226 and the pixel electrode 234 can be formed by the same process.
[0100]
In the liquid crystal devices according to the first to fourth embodiments, the data line 212 has a pattern that folds back every six subpixels. However, the number of subpixels that is a multiple of 6 is defined as one cycle. It is enough to wrap it. For example, 12 pieces, 18 pieces,... However, when the number of sub-pixels in one cycle in the folded pattern increases, problems such as an increase in the amount of data lines protruding at the end of the display area arise.
[0101]
In addition to the TFD 220, a three-terminal element such as a TFT can be used as the active element. Furthermore, the order of the colors displayed by the sub-pixels is not limited to the combinations shown in the embodiment, and it is needless to say that the colors may be arranged in a sequence of one multiple of 6 in each line. .
[0102]
<Electronic Device> Next, an example in which the liquid crystal device according to the above-described embodiment is used in an electronic device will be described.
[0103]
<Mobile Computer> First, an example in which this liquid crystal device is applied to a mobile computer will be described. FIG. 13 is a perspective view showing the configuration of the mobile computer. As shown in this figure, the mobile computer 1200 includes a keyboard 1233 having a plurality of keys 1232, a cover 1234 that opens and closes with respect to the keyboard 1233 as indicated by an arrow A, and a liquid crystal embedded in the cover 1234. The apparatus 100 is comprised. Here, the liquid crystal device 100 is obtained by mounting a backlight and other incidental devices on the liquid crystal device shown in FIGS.
[0104]
Further, inside the keyboard 1233, a control unit including a CPU (Central Processing Unit) that executes various calculations for performing a function as a mobile computer is stored. Then, the control unit executes arithmetic processing for displaying a predetermined video on the liquid crystal device 100.
[0105]
According to this mobile computer 1200, since the liquid crystal device 100 according to the above-described embodiment is applied to the display unit, high-definition and high-quality liquid crystal display can be performed, and furthermore, due to vertical crosstalk and horizontal crosstalk. It is possible to avoid a decrease in display image quality.
[0106]
<Pager> Next, a pager using this liquid crystal device will be described. FIG. 14 is an exploded perspective view showing the structure of the pager. As shown in the figure, the pager 1300 has a configuration in which the liquid crystal device 100 is housed in a metal frame 1302 together with a light guide 1306 including a backlight 1306a, a circuit board 1308, and first and second shield plates 1310 and 1312. It has become. In this configuration, conduction between the liquid crystal device 100 and the circuit board 1308 is achieved by the film tape 1314 for the element side substrate 200 and by the film tape 1318 for the counter substrate 300, respectively.
[0107]
In addition to the electronic devices described with reference to FIGS. 13 and 14, a liquid crystal television, a viewfinder type, a monitor direct view type video tape recorder, a car navigation device, an electronic notebook, a calculator, a word processor, a workstation, Examples of electronic devices include mobile phones, videophones, POS terminals, devices equipped with touch panels, and the like. Needless to say, the liquid crystal device according to the embodiment can be applied to these various electronic devices.
[0108]
Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention described in the claims.
[Brief description of the drawings]
FIG. 1 is a plan view schematically showing wiring (type 5) to sub-pixels in a liquid crystal device according to a first embodiment of the present invention.
FIG. 2 is an enlarged plan view showing an arrangement of sub-pixels in the liquid crystal device.
FIG. 3 is a perspective view showing a configuration of the liquid crystal device.
FIG. 4 is a cross-sectional view showing a configuration of the liquid crystal device.
FIG. 5 is a table in which the influence of coupling capacitance between a data line and a pixel electrode of a sub pixel on each sub pixel in each wiring is evaluated for each row.
FIG. 6 is an enlarged plan view showing an arrangement of sub-pixels in a liquid crystal device according to a second embodiment of the present invention.
FIG. 7 is a plan view showing a layout of an element substrate in a liquid crystal device according to a third embodiment of the present invention.
FIG. 8A is a partially enlarged view showing a layout for one pixel in the liquid crystal display device; B is a cross-sectional view taken along line AA in FIG. 8A.
FIG. 9 is a diagram showing a TFD manufacturing process in the apparatus.
FIG. 10 is a diagram showing a TFD manufacturing process in the apparatus.
FIG. 11 is a plan view showing a layout of an element substrate in a liquid crystal device according to a fourth embodiment of the present invention.
FIG. 12A is a partially enlarged view showing a layout of one pixel in the liquid crystal device. B is a partially enlarged view showing a layout for one pixel in the liquid crystal device.
FIG. 13 is a perspective view illustrating a configuration of a personal computer as an example of an electronic apparatus to which the liquid crystal device according to the embodiment of the invention is applied.
FIG. 14 is an exploded perspective view illustrating a configuration of a pager as an example of an electronic apparatus to which the liquid crystal device according to the embodiment of the invention is applied.
FIG. 15 is a plan view showing an RGB stripe arrangement.
FIG. 16 is a plan view showing an RGB mosaic arrangement.
FIG. 17 is a plan view showing an RGGB mosaic arrangement.
FIG. 18 is a plan view showing an RGB delta arrangement.
FIG. 19 is a plan view showing wiring (type 1) in an RGB delta arrangement.
FIG. 20 is a plan view showing wiring (type 2) in an RGB delta arrangement.
FIG. 21 is a voltage waveform diagram showing an example of a drive signal in the liquid crystal device.
FIG. 22 is a graph showing a VT curve when white is displayed (off) in a sub-pixel corresponding to a specific color;
FIG. 23 is a graph showing a VT curve when black is displayed (ON) in a sub-pixel corresponding to a specific color.
FIG. 24 is a plan view showing wiring (type 3) in an RGB delta arrangement.
FIG. 25 is a plan view showing wiring (type 4) in an RGB delta arrangement.

Claims (13)

A liquid crystal device in which sub-pixels corresponding to three different colors are arranged in a triangle,
While the conductive lines for applying a voltage to the sub-pixels are repeatedly connected to the pixel electrodes of the sub-pixels corresponding to the three colors in a certain order,
A liquid crystal device, wherein pixel electrodes commonly connected to one conduction line are arranged on the same side with respect to the conduction line. The conduction line is a data line, and as the length of the portion along the pixel electrode of the data line becomes longer, the distance between the data line and the pixel is increased or the data line is made thinner. The liquid crystal device according to claim 1. The liquid crystal device according to claim 1, wherein the conduction line is connected to the pixel electrode in a pattern in which a multiple of 6 is one period. The liquid crystal device according to claim 1, wherein the conduction line is connected to the pixel electrode through an active element. 5. The liquid crystal device according to claim 4, wherein the active element is a thin film diode element composed of a conductor / insulator / conductor. An electronic apparatus having a liquid crystal device in which subpixels corresponding to three different colors are arranged in a triangle,
While the conduction lines for applying voltages to the sub-pixels are repeatedly connected in a predetermined order to the pixel electrodes corresponding to the sub-pixels corresponding to the three colors,
An electronic device, wherein pixel electrodes commonly connected to one conduction line are arranged on the same side with respect to the conduction line. A liquid crystal device in which sub-pixels corresponding to three different colors are arranged in a triangle,
The liquid crystal device according to claim 1, wherein the conductive lines for applying a voltage to the sub-pixels are formed such that a parasitic capacitance with the pixel electrode of the sub-pixel is equalized over each sub-pixel. The liquid crystal device according to claim 7, wherein the periphery of the pixel electrode is surrounded by a conductive line connected to the pixel electrode. 8. The liquid crystal device according to claim 7, wherein the periphery of the pixel electrode other than the side facing the adjacent conductive line is surrounded by the conductive line connected to the pixel electrode with substantially the same width. . The liquid crystal device according to claim 7, wherein the conductive line is connected to the pixel electrode in a pattern in which a multiple of 6 is one period. The liquid crystal device according to claim 7, wherein the conduction line is connected to the pixel electrode through an active element. 12. The liquid crystal device according to claim 11, wherein the active element is a thin film diode element made of a conductor / insulator / conductor. An electronic device including a liquid crystal device in which subpixels corresponding to three different colors are arranged in a triangle,
The electronic device is characterized in that the conductive lines for applying a voltage to the sub-pixels are formed by equalizing the parasitic capacitance with the pixel electrodes of the sub-pixels over the sub-pixels.

Images