JP2010151884A - Liquid crystal device and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a liquid crystal device of an FFS system, in which transmissivity and response time are made compatible. <P>SOLUTION: In the liquid crystal device having: a first substrate 10 and a second substrate 11 arranged opposite to each other; a liquid crystal layer 50 sandwiched between the first substrate 10 and the second substrate 11; a first electrode 21 formed on the side of the liquid crystal layer 50 of the first substrate 10; and a second electrode 22 opposite to the first electrode 21 via a dielectric layer 34, one of the first electrode 21 and the second electrode 22 has a plurality of belt-like electrode parts 27 extending in parallel with one another by including predetermined intervals 28, when each interval 28 is defined as S(μm), width of each belt-like electrode part 27 is defined as L(μm), cell thickness of the liquid crystal layer 50 is defined as d(μm), layer thickness of the dielectric layer is defined as t(nm), and breakdown strength of a driver IC is defined as V<SB>IC</SB>, expression (1)80≤t≤(70×V<SB>IC</SB>-250)exp((L+S)/d) is satisfied. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal device and an electronic apparatus.

  An active matrix type liquid crystal device in which a switching TFT (thin film transistor) is formed for each pixel, which is one type of liquid crystal device, can display high-definition images and has been rapidly used in recent years. Among such active matrix types, the adoption of the IPS (In / Plane / Switching) method or the FFS ((Fringe / Field / Switch) method, which is a lateral electric field method, is progressing for the purpose of improving the viewing angle. The FFS mode is a mode in which an electric field is formed through the slits between the upper electrode on the liquid crystal layer side having slits laminated via a dielectric layer and the flat plate-like lower electrode. One of the electrodes is a pixel electrode and the other is a common electrode.

  The display characteristics of the FFS mode liquid crystal device are as follows: (Since one electrode is flat), the (short axis) width of the slit, the width of the strip electrode portion (band electrode), which is the distance between the slits, the dielectric layer thickness, etc. Greatly affects. Therefore, for the purpose of improving the display characteristics, Patent Document 1 discloses a configuration in which the slit width and the band-shaped electrode portion width are maintained at a certain value or more. Further, Patent Document 2 discloses a configuration in which the dielectric layer thickness is determined by the pixel density or the like in a display area where an image is displayed.

JP 2008-1116484 A JP 2008-1116485 A

  However, the above configuration does not take into account that the voltage at which the transmittance is maximized is affected by the dielectric layer thickness. Furthermore, the FFS liquid crystal device has a problem in that the transmittance and the response time are contradictory.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1] A first substrate and a second substrate arranged to face each other, a liquid crystal layer sandwiched between the first substrate and the second substrate, and the first substrate A first electrode formed on the liquid crystal layer side, a second electrode facing the first electrode through a dielectric layer,
A first electrode and a second electrode having a plurality of strip electrode portions extending in parallel with each other at a predetermined interval. , When the interval is S (μm), the width of the strip electrode portion is L (μm), the cell thickness of the liquid crystal layer is d (μm), and the layer thickness of the dielectric layer is t (nm) A liquid crystal device satisfying the following expression (1).
80 ≦ t ≦ (70 × V _IC −250) exp ((L + S) / d) (1)
V _IC is the breakdown voltage of the driver IC.

  In the liquid crystal device having such a configuration, the layer thickness of the dielectric layer can be determined according to the width of the strip electrode portion, the width of the gap, and the cell thickness of the liquid crystal layer, thereby increasing power consumption and manufacturing cost. The transmittance can be improved.

  Application Example 2 An electronic apparatus including the liquid crystal device described above.

  According to such a configuration, an electronic apparatus with improved display quality can be obtained without increasing power consumption or manufacturing cost.

(First embodiment)
First, a transflective liquid crystal device using the FFS method according to the present embodiment will be described with reference to the drawings. In all of the following drawings, the dimensions and ratios of the constituent elements are appropriately changed from the actual ones in order to make the constituent elements large enough to be recognized on the drawings.

  FIG. 1 is a diagram showing an equivalent circuit of the liquid crystal device according to the present embodiment. In the display region 100 of the liquid crystal device 1, a plurality of scanning lines 102 and common lines 106 extending in the X direction and a plurality of data lines 104 extending in the Y direction are formed in a grid pattern. A substantially rectangular area surrounded by the grid-like data lines 104 and the scanning lines 102 is a pixel area 41, and a pixel 40 is formed for each pixel area 41. Each pixel 40 includes a pixel electrode 21 as a first electrode, a TFT (thin film transistor) 20 that controls switching of the pixel electrode, a common electrode 22 (see FIG. 2) as a second pixel electrode, which will be described later, and the like. Is provided. Note that the pixel area 41 indicates a planar area, and the pixel 40 includes a functional meaning.

  The pixel 40 includes a red pixel 40R that emits red light, a green pixel 40G that emits green light, and a blue pixel 40B that emits blue light, each of which is regularly arranged in the X direction. By controlling the light emission intensities of the three types of pixels 40 individually, light having an arbitrary wavelength range is formed and emitted from the region composed of the three types of pixels 40. The three types of pixels 40 (40R, 40G, and 40B) described above may be referred to as “sub-pixels”, and a combination of the three types of sub-pixels may be referred to as “pixels”. The expression “pixel” is not used. The notation “pixel 40” is used as a general term for the above three types of pixels.

  As will be described later, the source electrode 20s (see FIG. 2) of the TFT 20 has a portion of the data line 104 protruding, and the gate electrode 20g (see FIG. 2) of the TFT 20 has a portion of the scanning line 102 protruding. It is a thing. The drain electrode 20 d (see FIG. 2) of the TFT 20 is electrically connected to the pixel electrode 21. The data line 104 is connected to the data line driving circuit 114, and the image signals S1, S2,..., Sn supplied from the data line driving circuit are supplied to each pixel 40. The scanning line 102 is connected to the scanning line driving circuit 112, and scanning signals G1, G2,..., Gm supplied from the scanning line driving circuit are supplied to each pixel 40. The image signals S1 to Sn supplied from the data line driving circuit 114 to the data lines 104 may be supplied line-sequentially in this order, or may be supplied for each of a plurality of adjacent data lines 104 for each group. Good. Further, the scanning line driving circuit 112 supplies the scanning signals G1 to Gm to the scanning line 102 in a pulse-sequential manner at a predetermined timing.

In the liquid crystal device 1, the TFT 20 serving as a switching element is turned on for a certain period by the input of the scanning signals G1 to Gm, so that the image signals S1 to Sn supplied from the data line 104 are supplied to the pixel electrode 21 at a predetermined timing. It is the structure written in. A predetermined level of image signals S1 to Sn written to the liquid crystal layer 50 (see FIG. 3) via the pixel electrode 21 is stacked later via the pixel electrode 21 and the dielectric layer 34 (see FIG. 3). It is held for a certain period with the common electrode 22 (see FIG. 3). The liquid crystal layer 50 (see FIG. 3) is driven by a lateral electric field generated between the pixel electrode 21 and the common electrode 22.
The common line 106 is a wiring that electrically connects each common electrode 22 (see FIG. 3) for each row. With the common line 106, the common electrode 22 of all the pixels 40 in the display region 100 is held at a common potential.

  FIG. 2 is a diagram schematically showing a planar configuration of the pixel 40 of the liquid crystal device 1 according to the present embodiment. An element substrate 10 (see FIG. 3) as a first substrate described later is also described later. It is the figure seen from the opposing board | substrate 11 (refer FIG. 3) side as 2 board | substrates. However, the reflection layer 35 (see FIG. 3) is not shown. This figure shows the above-described three types of pixels 40 (R, G, B) arranged in the X direction, but the type of such pixels is only a color filter 71 (see FIG. 3) described later formed on the counter substrate 11. All the configurations on the element substrate 10 side are common. Therefore, the following is a description of the components of the pixel 40 as a generic name.

  As shown in the figure, each pixel 40 includes, on the element substrate 10 side, a TFT 20 formed in the vicinity of the intersection of the scanning line 102 and the data line 104 formed in a grid pattern, a pixel electrode 21, a common electrode 22, have. A plurality of insulating layers (not shown) are formed between the elements. The TFT 20 includes a source electrode 20 s formed by protruding a part of the data line 104, a gate electrode 20 g formed by protruding a part of the scanning line 102, and the same layer as a material layer constituting the data line 104. A drain electrode 20d formed by patterning an island shape into the island shape, a semiconductor layer 20a made of an amorphous silicon layer patterned into an island shape, and the like.

  The pixel electrode 21 is a substantially rectangular member made of ITO (indium oxide / tin alloy), which is a transparent conductive material, and is electrically connected to the drain electrode 20d through a contact hole 20c. The pixel electrode 21 is formed between a band-shaped portion (hereinafter referred to as “band-shaped electrode portion”) 27 extending substantially in the X direction and a plurality of band-shaped electrode portions 27 formed at equal intervals so as to be aligned in the Y direction. It has a ladder-like planar shape made up of slits 28 that are separated. The extending direction of the strip electrode part 27 has an inclination of 5 degrees with respect to the X direction. The dimension in the direction orthogonal to the extending direction of the strip electrode part 27, that is, the width is the strip electrode part width L, and the same dimension in the slit 28, that is, the width is the slit width S. The sum (L + S) of the strip electrode width L and the slit width S is the electrode pitch P.

  Similar to the pixel electrode 21, the common electrode 22 is a substantially rectangular member made of ITO, and is formed in a region that substantially overlaps the pixel electrode 21 in a plan view except for the vicinity of the contact hole 20c. A region where the pixel electrode 21 and the common electrode 22 overlap is a region where light is actually emitted. The common electrode 22 has a flat plate shape having no slit or the like, and is electrically insulated from the TFT 20 and the pixel electrode 21. The region from which the light is emitted is divided into a transmissive display region T and a reflective display region R by a dividing line drawn in the X direction (a dot-and-dash line without a symbol). The spacer 29 is a columnar member and functions to maintain the distance between the counter substrate 11 and the element substrate 10.

  FIG. 3 is a diagram schematically showing a cross section taken along the line A-A ′ of FIG. 2. As illustrated, the liquid crystal device 1 includes an element substrate 10, a counter substrate 11, a liquid crystal layer 50 sandwiched between the pair of substrates (the element substrate 10 and the counter substrate 11), and the liquid crystal of the element substrate 10. It comprises a light source (not shown) disposed on the opposite side of the layer 50 side. Since the liquid crystal device 1 is a transflective type, at the time of transmissive display, the light emitted from the light source described above is transmitted through the transmissive display region T and emitted from the counter substrate 11 side. Therefore, both of the pair of substrates described above are formed of a transparent material such as glass.

  The first polarizing plate 65 is disposed on the surface of the element substrate 10 opposite to the liquid crystal layer 50 side, and the phase difference plate 67 and the second polarizing plate 65 are disposed on the surface of the counter substrate 11 opposite to the liquid crystal layer 50 side. Polarizing plates 66 are arranged in order. In the following description, the direction on the liquid crystal layer 50 side of the element substrate 10 is referred to as “upper”, “upper layer”, or “upper surface”.

  On the upper surface of the element substrate 10, a gate electrode 20 g which is a part of the common line 106 and the scanning line 102 is formed. A common electrode 22 that covers the common line is formed in a region extending between the transmissive display region T and the reflective display region R. In the reflective display region R, the reflective layer 35 and the light scattering imparting means 36 are sequentially formed between the common electrode and the element substrate 10. The reflective layer 35 is made of a metal material having high reflectivity such as Al (aluminum) or Ag (silver), and reflects external light incident through the counter substrate 11 during reflection display from the counter substrate 11 side. Eject. The light scattering imparting means 36 functions as a base for imparting irregularities to the surface of the reflective layer, and is formed by half-exposing the photosensitive resin layer.

  A gate insulating layer 33 made of silicon nitride or silicon oxide is formed on the entire surface of the element substrate 10 on the common electrode 22 and the gate electrode 20g. A drain electrode 20d, a source electrode 20s, and a semiconductor layer 20a are formed on the gate insulating layer 33. As described above, the TFT 20 is configured by the drain electrode and the like, the gate insulating layer 33, and the gate electrode 20g.

  On the TFT 20, an interlayer insulating layer 30 made of silicon nitride or silicon oxide, a pixel electrode 21, and a first alignment film 61 are sequentially formed. Therefore, a stacked body of the gate insulating layer 33 and the interlayer insulating layer 30 is formed between the common electrode 22 and the pixel electrode 21. Such a laminate is a dielectric layer 34. A contact hole 20c that connects the pixel electrode 21 and the drain electrode 20d is formed by patterning the interlayer insulating layer 30. In the liquid crystal device 1, the liquid crystal layer 50 is driven by an electric field formed between the pixel electrode 21 and the common electrode 22 through the dielectric layer, and the amount of external light reflected or light emitted from a light source (not shown). The amount of transmission is controlled.

  The liquid crystal material constituting the liquid crystal layer 50 is a negative liquid crystal material having a negative dielectric anisotropy. The refractive index anisotropy Δn is 0.12 (wavelength 589 nm). Note that a positive liquid crystal material having a positive dielectric anisotropy can also be used. In such a case, it is preferable to arrange a shield layer made of a transparent conductive material between the counter substrate 11 and the phase difference plate 67.

  In a region excluding the reflective display region R and the transmissive display region T on the surface of the counter substrate 11 on the liquid crystal layer 50 side, a black matrix 72 made of a resin containing a light shielding material is formed. Further, a color filter 71 is formed on the entire surface of the counter substrate 11 including the black matrix forming region on the liquid crystal layer 50 side. The color filter 71 and the black matrix 72 form the color filter layer 70. The color filter 71 transmits light in a wavelength region corresponding to any one of red light, green light, and blue light, thereby allowing white light or external light emitted from a light source (not shown) to be one of the three primary colors. The light is colored.

  On the liquid crystal layer 50 side of the color filter layer 70 in the reflective display region R, a liquid crystal layer thickness adjusting layer 68 is formed, and a second alignment film 62 is formed so as to cover the liquid crystal layer thickness adjusting layer. A first alignment film 61 is formed on the pixel electrode 21 of the element substrate 10. Therefore, the liquid crystal layer 50 is sandwiched between the first alignment film 61 and the second alignment film 62. The rubbing direction of both the alignment films, that is, the alignment regulating direction is the Y direction (see FIG. 2), that is, the extending direction of the data line 104, and the liquid crystal layer 50 in the state where no electric field is formed between the pair of electrodes. The long axes of the liquid crystal molecules are aligned in the Y direction. On the other hand, the polarizing axes of the pair of polarizing plates are such that the polarizing axis of the first polarizing plate 65 is perpendicular to the Y direction and the polarizing axis of the second polarizing plate 66 is perpendicular to the X direction.

(optimisation)
As described above, the FFS type liquid crystal device such as the liquid crystal device 1 according to the present embodiment includes the slit 28 and the dielectric layer 34, that is, the interlayer insulating layer, between the strip electrode portion 27 of the pixel electrode 21 and the common electrode 22. The liquid crystal layer 50 is driven by an electric field formed through the stacked body of the gate electrode 30 and the gate insulating layer 33 to display an image. Therefore, display quality can be improved by optimizing the dimensions and the like of each element. In the liquid crystal device 1 according to the present embodiment, the dimensions and the like are determined as follows.

  FIG. 4 shows the relationship between the drive voltage applied between the pair of electrodes and the transmittance when the slit width S is constant and the strip electrode width L is changed (hereinafter referred to as “VT characteristic”). FIG. 5 is a diagram showing VT characteristics when the slit width S is changed with the band-shaped electrode portion width L being constant, and FIG. 6 is a graph showing the change in the electrode pitch P (band electrode portion width L + slit width S). It is a figure which shows the VT characteristic when letting it be made. From FIG. 3, it can be seen that the transmittance is improved by reducing the width L of the strip electrode portion, the slit width S, or the electrode pitch P. However, on the other hand, the drive voltage (hereinafter referred to as “Vmax”) when the transmittance is maximum increases. An increase in Vmax is undesirable because it increases power consumption. Further, if the drive voltage exceeds 5.0 (V), a general-purpose driver IC cannot be used, which may increase the manufacturing cost.

FIG. 7 is a graph showing VT characteristics when the thickness of the dielectric layer 34 (hereinafter referred to as “dielectric layer thickness”) is changed. As shown in the figure, Vmax decreases as the dielectric layer thickness decreases. Therefore, by controlling the induction layer thickness, the transmittance can be improved without increasing Vmax.
FIG. 8 is a diagram showing VT characteristics when the cell thickness d, that is, the layer thickness of the liquid crystal layer 50 is changed. The band electrode width L, slit width S, and electrode pitch P are constant, and the phase difference of the liquid crystal layer 50 is also constant. As shown in the figure, the transmittance increases as the cell thickness d increases. However, in the FFS type liquid crystal device, it is known that an increase in the cell thickness d increases the response time. That is, in the FFS type liquid crystal device, the problem is that the transmittance and the response time are contradictory.

  FIG. 9 is a diagram in which the relationship between the white display transmittance and the electrode pitch P is plotted for each cell thickness d measured in FIG. Here, the white display transmittance is defined as a transmittance of 95% of the maximum transmittance. As shown in the figure, the transmittance tends to decrease as the cell thickness d is reduced, but the white display transmittance is 0.25 at the cell thickness d = 3.0 μm and the electrode pitch P = 8.0 μm. Similarly, when the cell thickness is d = 2.0 μm and the electrode pitch P is 6.0 μm, the white display transmittance is 0.25. That is, the transmittance and response characteristics can be maintained or improved by setting the electrode pitch P (or the strip electrode width L and the slit width S) according to the cell thickness d.

  FIG. 10 is a diagram in which the change in white display transmittance with respect to the ratio between the electrode pitch P and the cell thickness d is plotted in three stages. The transmittance is improved as the ratio between the electrode pitch P and the cell thickness d is reduced, and the increase in the transmittance is saturated when the ratio between the electrode pitch P and the cell thickness d reaches approximately 2.0. I understand. If the transmittance varies by about 10%, the influence on the display quality is small. Therefore, the ratio between the electrode pitch P and the cell thickness d can be allowed up to about 2.7. It can also be seen that even if the ratio between the width L of the strip electrode portion constituting the electrode pitch P and the slit width S changes, the transmittance is hardly affected.

  FIG. 11 is a diagram showing the relationship between the ratio (P / d) between the electrode pitch P and the cell thickness d and the response time tr. The response time tr decreases with a decrease in the ratio (P / d) between the electrode pitch P and the cell thickness d, and is substantially saturated within a range of 0.8 ≦ (P / d) ≦ 2.1. If the response time tr varies by about 10%, the influence on the display quality is small. Therefore, the response time tr is acceptable within the range of 0.5 ≦ (P / d) ≦ 2.9. From the above, from the viewpoint of transmittance and response time, the ratio (P / d) of electrode pitch P to cell thickness d is preferably in the range of 0.5 to 2.9.

  FIG. 12 is a diagram in which the horizontal axis represents the ratio (P / d) between the electrode pitch P and the cell thickness d, the vertical axis represents the dielectric layer thickness t, and the driving voltage for white display transmittance is the same. It is. Since the transmittance can be improved without increasing Vmax as the dielectric layer thickness t is reduced as described above, the upper limit of the drive voltage can be increased by reducing the dielectric layer thickness t in accordance with (P / d). Display quality such as transmittance can be improved while keeping the value below a certain value.

  As described above, since the breakdown voltage of a general driver IC is 5.0 (V) or less, the drive voltage is 4.0 (V), 4.5 (V), or 5.0 (V). The stages are illustrated. From FIG. 12, the strip electrode portion width L, the slit width S and the cell thickness d of the pixel electrode 21 are determined according to the withstand voltage of the driver IC, and the upper limit of the drive voltage is set according to the withstand voltage of the driver IC to be employed next. It can be seen that by setting the dielectric layer thickness t in accordance with the numerical values of the respective elements, a liquid crystal device with reduced power consumption and manufacturing cost and improved display quality can be obtained.

From the curve shown in FIG. 12, Equation (1) for setting the optimum dielectric layer thickness t (nm) can be derived as follows.
80 ≦ t ≦ (70 × V _IC −250) exp ((L + S) / d) (1)
As described above, V _IC is the breakdown voltage of the driver IC. The reason why the lower limit of the dielectric layer thickness t is set to 80 nm is that the unevenness of the upper layer of the common electrode 22 due to the unevenness of the reflective layer 35 is taken into consideration. According to the formula (1), for example, when the cell thickness d is 3.0 μm and the electrode pitch P is 4.8 μm, the drive voltage that provides white display transmittance can be obtained by setting the dielectric layer thickness t to 500 nm or less. It can be seen that it can be suppressed to 5.0 (V) or less, which is the withstand voltage of the driver IC.

(Second Embodiment)
Next, the liquid crystal device 2 according to the second embodiment will be described. FIG. 13 is a schematic cross-sectional view of the liquid crystal device 2 according to the second embodiment. It is a schematic cross section in the same position as the AA 'line of Drawing 2 in a 1st embodiment. The liquid crystal device 2 according to the present embodiment is characterized by using an overlayer structure. Except for the difference in structure, the liquid crystal device 2 has substantially the same configuration as the liquid crystal device 1 of the first embodiment. Therefore, common constituent elements are given the same reference numerals, and description thereof is partially omitted.

  The overlayer structure is a structure in which the common electrode 22 and the like are formed in the upper layer of the TFT 20. That is, the first interlayer insulating layer 31 is formed above the TFT 20, and the common electrode 22 is formed above the first interlayer insulating layer. The pixel electrode 21 faces the common electrode 22 with the second interlayer insulating layer 32 interposed therebetween. Therefore, only the second interlayer insulating layer 32 functions as the dielectric layer 34. The layer thickness of the second interlayer insulating layer 32 (that is, the dielectric layer 34) is determined by the above-described equation (1) as in the liquid crystal device 1. The contact hole 20c is formed so as to penetrate the stacked body of the first interlayer insulating layer 31 and the second interlayer insulating layer 32.

  In the liquid crystal device 2 according to the present embodiment, since the gate insulating layer 33 is not included in the dielectric layer 34, the thickness of the gate insulating layer can be freely set. Further, the minimum layer thickness (that is, the lower limit of the layer thickness) of the dielectric layer 34 can be set in consideration of only the unevenness of the reflective layer 35. Therefore, the degree of freedom in setting the dimensions of each constituent element is improved and the number of steps is slightly increased, but an effect of improving the display quality can be obtained.

(Electronics)
FIG. 14 is a perspective view showing a mobile phone as an example of the electronic apparatus according to the present embodiment. A mobile phone 90 shown in FIG. 14 includes the liquid crystal device (1 or 2) of the above embodiment as a display unit 92, and includes a plurality of operation buttons 94, an earpiece 96, and a mouthpiece 98. . Since the transmittance of the liquid crystal device 1 or 2 is improved without increasing the driving voltage, the mobile phone 90 with improved display quality is realized without increasing power consumption and manufacturing cost.

  The liquid crystal device according to the embodiment is not limited to the mobile phone 90, but is an electronic book, a personal computer, a digital still camera, a liquid crystal television, a viewfinder type or a monitor direct view type video tape recorder, a car navigation device, a pager, and an electronic device. It is preferably used as an image display means for notebooks, calculators, word processors, workstations, videophones, POS terminals, devices equipped with touch panels, 3D liquid crystal devices using a field sequential (FS) display system, two-screen liquid crystal devices, etc. it can. In any electronic device, display quality is improved without increasing power consumption or manufacturing cost.

(Modification)
The liquid crystal device 1 and the liquid crystal device 2 described above are transflective liquid crystal devices. However, the above formula (1) can also be applied to a transmissive liquid crystal device and a reflective liquid crystal device. The display quality can be improved by setting the dielectric layer thickness in accordance with the band-like electrode portion width L, the cell thickness d, and the like.

1 is a diagram showing an equivalent circuit of a liquid crystal device according to a first embodiment. FIG. 3 is a diagram schematically illustrating a planar configuration of a pixel of the liquid crystal device according to the first embodiment. 1 is a schematic cross-sectional view of a liquid crystal device according to a first embodiment. The VT characteristic figure when changing a strip | belt-shaped electrode part width | variety, making slit width constant. The VT characteristic figure when changing a slit width | variety, making a strip | belt-shaped electrode part width | variety constant. The VT characteristic figure when changing an electrode pitch. The VT characteristic figure when changing a dielectric layer thickness. The figure which shows the VT characteristic when changing cell thickness. The figure which plotted the relationship between white display transmittance | permeability and electrode pitch for every cell thickness. The figure which plotted the change of the white display transmittance | permeability with respect to ratio of an electrode pitch and cell thickness. The figure which shows the relationship between ratio of an electrode pitch and cell thickness, and response time. The figure which connected the point from which the drive voltage used as white display transmittance | permeability becomes the same by making the ratio of electrode pitch and cell thickness into a horizontal axis, and making dielectric layer thickness into a vertical axis | shaft. FIG. 6 is a schematic cross-sectional view of a liquid crystal device according to a second embodiment. The perspective view which shows the portable telephone as an example of an electronic device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal device, 2 ... Liquid crystal device, 10 ... Element board | substrate as 1st board | substrate, 11 ... Counter board | substrate as 2nd board | substrate, 20 ... TFT, 20a ... Semiconductor layer, 20d ... Drain electrode, 20c ... Contact hole , 20g ... gate electrode, 20s ... source electrode, 21 ... pixel electrode as first pixel electrode, 22 ... common electrode as second pixel electrode, 27 ... strip electrode part, 28 ... slit, 29 ... spacer, 30 ... Interlayer insulating layer, 31 ... First interlayer insulating layer, 32 ... Second interlayer insulating layer, 33 ... Gate insulating layer, 34 ... Dielectric layer, 35 ... Reflective layer, 36 ... Light scattering imparting means, 40B ... Blue pixel 40G ... green pixel, 40R ... red pixel, 41 ... pixel region, 50 ... liquid crystal layer, 61 ... first alignment film, 62 ... second alignment film, 65 ... first polarizing plate, 66 ... second Polarizing plate, 67 ... retardation plate, 68 ... Crystal layer thickness adjusting layer, 70 ... Color filter layer, 71 ... Color filter, 72 ... Black matrix, 90 ... Mobile phone as an electronic device, 92 ... Display unit, 94 ... Operation button, 96 ... Earpiece, 98 ... Sending Talk port 100 ... Display area 102 ... Scan line 104 ... Data line 106 ... Common line 112 ... Scan line drive circuit 114 ... Data line drive circuit L ... Strip electrode width, P ... Electrode pitch, R ... reflective display area, S ... slit width, T ... transmissive display area.

Claims (2)

A first substrate and a second substrate disposed opposite to each other;
A liquid crystal layer sandwiched between the first substrate and the second substrate;
A first electrode formed on the liquid crystal layer side of the first substrate;
A second electrode facing the first electrode via a dielectric layer;
A liquid crystal device comprising:
One of the first electrode and the second electrode has a plurality of strip electrode portions extending in parallel with each other at a predetermined interval,
When the interval is S (μm), the width of the strip electrode portion is L (μm), the cell thickness of the liquid crystal layer is d (μm), and the layer thickness of the dielectric layer is t (nm), A liquid crystal device satisfying the following formula (1).
80 ≦ t ≦ (70 × V _IC −250) exp ((L + S) / d) (1)
V _IC is the breakdown voltage of the driver IC.   An electronic apparatus comprising the liquid crystal device according to claim 1.

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