JP2012163653A - Electro-optic device and electronic apparatus - Google Patents

Abstract

In an electro-optical device, contrast and brightness are selectively increased.
An electro-optical device is provided so as to overlap with a scanning line (11) and is formed to overlap with a region including a gap region located between pixel electrodes adjacent to each other in a direction in which a data line extends. An electrode (400), an image signal supply unit (101, 95, 7) for supplying an image signal whose polarity is inverted every predetermined period with respect to a reference potential to the data line, and a conductive for supplying a conductive electrode potential to the conductive electrode And an electrode potential supply unit (300). The conductive electrode potential supply unit controls the first operation mode for controlling the conductive electrode potential so as to have the same polarity as the image signal supplied to the pixel electrode, and the conductive electrode has the same potential as the reference potential. A second operation mode for controlling the conductive electrode potential.
[Selection] Figure 3

Description

  The present invention relates to a technical field of an electro-optical device such as a liquid crystal device and an electronic apparatus such as a liquid crystal projector including the electro-optical device.

  In a liquid crystal device that is an example of this type of electro-optical device, a liquid crystal that is an example of an electro-optical material is sandwiched between a pair of element substrates and a counter substrate. In the pixel region on the element substrate, for each pixel, a pixel electrode, a scanning line for selectively driving the pixel electrode, a data line, and a TFT (Thin Film Transistor) for pixel switching form an interlayer insulating film. Thus, it is built as a laminated structure, and is configured to be capable of active matrix driving. The pixel electrode is disposed, for example, in the uppermost layer in the stacked structure on the element substrate. In addition, a storage capacitor (or an auxiliary capacitor) may be provided between the pixel switching TFT and the pixel electrode for the purpose of increasing the contrast or the like (see, for example, Patent Document 1).

  On the other hand, on the side of the counter substrate that faces the element substrate, typically, the counter electrode is formed in common with respect to the plurality of pixel electrodes over substantially the entire pixel region. When the liquid crystal device is driven, the counter electrode is maintained at a predetermined reference potential, and an applied voltage based on a potential difference between the pixel electrode and the counter electrode is applied to the liquid crystal in each pixel. At this time, for example, the image signal is supplied to the pixel electrode after being inverted in polarity to either a positive polarity or a negative polarity with respect to a predetermined reference potential.

  For example, in Patent Document 1, one capacitor electrode of a pair of capacitor electrodes constituting a storage capacitor (or auxiliary capacitor) is electrically connected to a counter electrode, and the other capacitor electrode is electrically connected to a pixel electrode. A configuration is disclosed. When one capacitor electrode is electrically connected to the counter electrode in this way, one capacitor electrode is maintained at the same potential as the counter electrode (that is, a predetermined reference potential). A shield electrode that prevents electrical or electromagnetic coupling between a lower layer side (for example, a data line) of the one capacitor electrode and a pixel electrode provided on the upper layer side of the one capacitor electrode between adjacent pixel electrodes. Can function as. Such a shield electrode may be provided between adjacent pixel electrodes on the element substrate independently of the storage capacitor.

Japanese Patent No. 3544572

  However, as described above, when the shield electrode is maintained at the same potential as the counter electrode (that is, when both the shield electrode and the counter electrode are maintained at a predetermined reference potential), the shield electrodes are adjacent to each other depending on the potential of the shield electrode. There is a possibility that it is difficult to sufficiently apply an applied voltage to be applied to the liquid crystal positioned between the matching pixel electrodes. That is, in this case, the potential of the shield electrode may adversely affect the applied voltage applied to the liquid crystal positioned between adjacent pixel electrodes. For this reason, when the liquid crystal device is in a normally white mode in which, for example, a TN (Twisted Nematic) liquid crystal is used, it is difficult to increase the blackness between adjacent pixel electrodes, for example, and the contrast of the display image is reduced. There is a technical problem that it may decrease. Further, when the liquid crystal device is in a normally black mode in which, for example, VA (Vertical Alignment) liquid crystal is used, it is difficult to increase the whiteness (in other words, brightness) between adjacent pixel electrodes, for example. There is a technical problem that the brightness of the display image may be lowered.

  The present invention has been made in view of, for example, the above-described problems. For example, an electro-optical device capable of selectively increasing contrast and brightness and performing high-quality display, and such an electric device. It is an object to provide an electronic device including an optical device.

  In order to solve the above problems, the electro-optical device of the present invention is provided on the substrate corresponding to the intersection of the data line and the scanning line, and the data line and the scanning line provided on the substrate so as to intersect each other. Between the pixel electrode, the counter electrode provided to face the pixel electrode and supplied with a predetermined reference potential, and the substrate and the pixel electrode so as to overlap the scanning line, A conductive electrode formed so as to overlap a region including a gap region located between pixel electrodes adjacent to each other in a direction in which the data line extends, and an image signal whose polarity is inverted every predetermined period with respect to the reference potential. An image signal supply unit configured to supply the data line; and a conductive electrode potential supply unit configured to supply a conductive electrode potential to the conductive electrode, wherein the conductive electrode potential supply unit includes the image signal supplied to the pixel electrode; same A first operation mode for controlling the conductive electrode potential so as to have a polar potential; and a second operation mode for controlling the conductive electrode potential so that the conductive electrode has the same potential as the reference potential. .

  According to the electro-optical device of the present invention, during the operation, a predetermined reference potential is supplied to the counter electrode and an image signal is supplied to the pixel electrode. In each pixel, according to a potential difference between the pixel electrode and the counter electrode. The applied voltage is applied to an electro-optical material such as liquid crystal. As a result, it is possible to display an image in a display area where the pixel electrode is provided. At this time, the image signal is supplied to the pixel electrode by the image signal supply unit with the polarity reversed to either a positive polarity or a negative polarity with respect to a predetermined reference potential. Here, “positive polarity” according to the present invention means that the potential of the image signal is higher than a predetermined reference potential, and the positive polarity image signal has a potential higher than the predetermined reference potential. The “negative polarity” according to the present invention means that the potential of the image signal is lower than a predetermined reference potential, and the negative image signal has a potential lower than the predetermined reference potential.

  In the present invention, the conductive electrode is provided between the substrate and the pixel electrode (in other words, on the lower layer side than the pixel electrode in the stacked structure on the substrate). The conductive electrode is provided so as to overlap the scanning line. For example, the conductive electrode is provided so as to make a pair with each of the plurality of scanning lines, and is formed so as to extend along a direction in which the scanning line extends (for example, the X direction). Further, the conductive electrode is formed so as to overlap with a region including a gap region located between pixel electrodes adjacent to each other in the direction in which the data line extends (for example, the Y direction). For example, each of the plurality of conductive electrodes is formed so as to substantially overlap a scanning line paired with the conductive electrode, thereby forming a region including a gap region between pixel electrodes adjacent to each other in the direction in which the data line extends. Is done. The conductive electrode potential is supplied to the conductive electrode by the conductive electrode potential supply unit. By supplying a conductive electrode potential to the conductive electrode, electrical or electromagnetic coupling between a lower layer side (for example, a data line) of the conductive electrode and a pixel electrode provided on the upper layer side of the conductive electrode is performed in the gap region. Can be prevented.

  In the present invention, in particular, the conductive electrode potential supply unit has a first operation mode in which the conductive electrode potential is controlled to have the same polarity as the image signal supplied to the pixel electrode, and the conductive electrode is the same as the reference potential. And a second operation mode in which the conductive electrode potential is controlled so as to have a potential.

  Therefore, when the conductive electrode potential supply unit operates in the first operation mode, a difference in voltage applied to the electro-optical material can be reduced between the region where the pixel electrode is provided and the gap region. Therefore, for example, when the electro-optical device is a normally white mode liquid crystal device in which, for example, TN liquid crystal is used as the electro-optical material, the blackness in the gap region can be increased, and the contrast of the display image can be increased. Can be improved. For example, when the electro-optical device is a normally black mode liquid crystal device in which, for example, VA liquid crystal or the like is used as the electro-optical material, whiteness (in other words, brightness) in the gap region can be increased. And the brightness of the display image can be improved.

  On the other hand, when the conductive electrode potential supply unit operates in the second operation mode, the voltage applied to the electro-optical material located in the gap region can be made lower than the voltage located in the region where the pixel electrode is provided. it can. Therefore, for example, when the electro-optical device is a normally white mode liquid crystal device in which, for example, TN liquid crystal is used as the electro-optical material, whiteness in the gap region can be increased, and the brightness of the display image can be increased. Can be improved. Further, for example, when the electro-optical device is a normally black mode liquid crystal device in which, for example, VA liquid crystal is used as an electro-optical material, the blackness in the gap region can be increased, and the contrast of the display image can be increased. Can be improved.

  Therefore, when the conductive electrode potential supply unit operates in one of the first and second operation modes, either the contrast or brightness of the display image can be increased. That is, for example, depending on whether the user attaches importance to contrast or brightness, the conductive electrode potential supply unit operates in one of the first and second operation modes, so that the contrast and brightness are selectively increased. It is possible to display a high-quality image.

  As described above, according to the electro-optical device of the present invention, contrast and brightness can be selectively increased, and high-quality display can be performed.

  In one aspect of the electro-optical device of the present invention, the electro-optical device includes a designation unit that designates which of the first and second operation modes the conductive electrode potential supply unit should operate.

  According to this aspect, the conductive electrode potential supply unit operates in the operation mode designated by the designation unit. Therefore, the user can select one of the first and second operation modes by the designation unit. Therefore, for example, it is possible to surely perform display according to whether the user places importance on contrast or brightness. That is, when the user places importance on the contrast of the display image, the contrast of the display image can be reliably increased, and when the user places importance on the brightness of the display image, the brightness of the display image can be ensured. Can be increased.

  In the aspect including the designation unit described above, the electro-optical device is a normally white mode liquid crystal device, and the designation unit sets the first operation mode as a contrast emphasis mode in which contrast is important, The second operation mode may be set as a brightness priority mode in which brightness should be emphasized.

  In this case, it is possible to realize a normally white mode liquid crystal device capable of reliably performing display in accordance with whether the user places importance on contrast or brightness.

  In the aspect including the specifying unit described above, the electro-optical device is a normally black mode liquid crystal device, and the specifying unit sets the first operation mode as a brightness priority mode in which brightness is important. The second operation mode may be set as a contrast emphasis mode in which contrast should be emphasized.

  In this case, it is possible to realize a normally black mode liquid crystal device capable of reliably performing display in accordance with whether the user attaches importance to contrast or brightness.

  In another aspect of the electro-optical device of the present invention, the electro-optical device is disposed between the substrate and the conductive electrode so as to face the conductive electrode through a dielectric film, and is electrically connected to the pixel electrode. The pixel potential side capacitor electrode is provided, and the conductive electrode forms a capacitor line.

  According to this aspect, the storage capacitor is configured by the conductive electrode, the dielectric film, and the pixel potential side capacitor electrode. The storage capacitor can reduce or prevent the leakage of the image signal held in the pixel electrode, and can increase the contrast. Furthermore, since the conductive electrode also serves as one of the pair of capacitive electrodes constituting the storage capacitor, for example, the laminated structure on the substrate is different from the case where the conductive electrode and the storage capacitor are provided separately in the laminated structure on the substrate. Can be simplified. In addition, since the capacitor line for supplying a predetermined potential to the storage capacitor is formed by the conductive electrode, the stacked structure on the substrate can be further simplified.

  In order to solve the above problems, an electronic apparatus according to the present invention includes the electro-optical device according to the present invention described above (including various aspects thereof).

  According to the electronic apparatus of the present invention, since the electro-optical device of the present invention described above is provided, a projection display device, a television, a mobile phone, an electronic notebook, a word processor, and a viewfinder type capable of performing high-quality display. Alternatively, various electronic devices such as a monitor direct-view video tape recorder, a workstation, a videophone, a POS terminal, and a touch panel can be realized. Also, as an electronic apparatus of the present invention, for example, an electrophoretic device such as electronic paper, an electron emission device (Field Emission Display and Conduction Electron-Emitter Display), and a display device using these electrophoretic device and electron emission device are realized. Is also possible.

  The effect | action and other gain of this invention are clarified from the form for implementing invention demonstrated below.

It is a top view which shows the whole structure of the liquid crystal device which concerns on 1st Embodiment. It is the II-II 'sectional view taken on the line of FIG. 1 is a block diagram illustrating an electrical configuration of a liquid crystal device according to a first embodiment. It is a top view which shows the structure of the shield line of the liquid crystal device which concerns on 1st Embodiment with the structure of a pixel electrode, a data line, and a scanning line. FIG. 5 is a cross-sectional view taken along line V-V ′ in FIG. 4. 6 is a timing chart showing a change with time of the potential of the shield line when the shield potential control circuit of the liquid crystal device according to the first embodiment operates in the first operation mode. 10 is a table showing a comparison between the potential of the shield line when the brightness emphasis mode is designated and the potential of the shield line when the contrast emphasis mode is designated. (A) shows the case of normally white mode, and (b) shows the case of normally black mode. It is a block diagram which shows the electric constitution of the liquid crystal device which concerns on 2nd Embodiment. Sectional drawing which shows the structure of the shield line and storage capacitor of the liquid crystal device which concerns on 2nd Embodiment It is a top view which shows the structure of the projector which is an example of the electronic device to which the electro-optical apparatus is applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a TFT active matrix driving type liquid crystal device which is an example of the electro-optical device of the present invention is taken as an example.

<First Embodiment>
The liquid crystal device according to the first embodiment will be described with reference to FIGS.

  First, the overall configuration of the liquid crystal device according to the present embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a plan view showing the overall configuration of the liquid crystal device according to the present embodiment, and FIG. 2 is a cross-sectional view taken along the line II-II ′ of FIG.

  1 and 2, in the liquid crystal device 100 according to the present embodiment, the TFT array substrate 10 and the counter substrate 20 are disposed so as to face each other. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20, and the TFT array substrate 10 and the counter substrate 20 are provided with a sealing material provided in a seal region 52a located around the image display region 10a. 52 are bonded to each other. The TFT array substrate 10 is an example of the “substrate” according to the present invention.

  In FIG. 1, a light-shielding frame light-shielding film 53 that defines the frame area of the image display region 10 a is provided on the counter substrate 20 side in parallel with the inside of the seal region 52 a where the sealing material 52 is disposed. Of the peripheral regions located around the image display region 10 a, the data line driving circuit 101 and the external circuit connection terminal 102 are provided on the TFT array substrate 10 in the region located outside the seal region 52 a where the sealing material 52 is disposed. It is provided along one side. The sampling circuit 7 is provided so as to be covered with the frame light-shielding film 53 on the inner side of the seal region 52a along the one side. Further, the scanning line driving circuit 104 is provided so as to be covered with the frame light-shielding film 53 inside the seal region 52a along the side adjacent to the one side. A shield potential control circuit 300 is provided so as to be covered with the frame light shielding film 53 along a side opposite to the side where the scanning line driving circuit 104 is provided. On the TFT array substrate 10, vertical conduction terminals 106 for connecting the two substrates with the vertical conduction material 107 are arranged in regions facing the four corner portions of the counter substrate 20. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20.

  On the TFT array substrate 10, a lead wiring for electrically connecting the external circuit connection terminal 102, the data line driving circuit 101, the scanning line driving circuit 104, the shield potential control circuit 300, the vertical conduction terminal 106, and the like. 90 is formed.

  In FIG. 2, on the TFT array substrate 10, a laminated structure is formed in which wirings such as TFTs for pixel switching, scanning lines, and data lines are formed. In the image display area 10a, pixel electrodes 9 made of a transparent conductive material such as ITO (Indium Tin Oxide) are provided in a matrix on the upper layer of wiring such as pixel switching TFTs, scanning lines, and data lines. An alignment film is formed on the pixel electrode 9. On the other hand, a light shielding film 23 is formed on the surface of the counter substrate 20 facing the TFT array substrate 10. The light shielding film 23 is formed of, for example, a light shielding metal film or the like, and is patterned, for example, in a lattice shape in the image display region 10a on the counter substrate 20. A counter electrode 21 made of a transparent conductive material such as ITO is formed in a solid shape on the light shielding film 23 so as to face the plurality of pixel electrodes 9. An alignment film is formed on the counter electrode 21. Further, the liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films.

  Although not shown here, in addition to the data line driving circuit 101 and the scanning line driving circuit 104, the TFT array substrate 10 is used for inspecting the quality, defects, etc. of the liquid crystal device during manufacturing or at the time of shipment. An inspection circuit, an inspection pattern, or the like may be formed.

  Next, the electrical configuration of the liquid crystal device 100 according to the present embodiment will be described with reference to FIG.

  FIG. 3 is a block diagram showing an electrical configuration of the liquid crystal device 100 according to the present embodiment.

  As shown in FIG. 3, the liquid crystal device 100 according to this embodiment includes a scanning line driving circuit 104, a data line driving circuit 101, a sampling circuit 7, and a shield potential control circuit 300 in the peripheral region on the TFT array substrate 10. A drive circuit (or peripheral circuit) including the image signal line 95 is provided. The shield potential control circuit 300 is an example of the “conductive electrode potential supply unit” according to the present invention, and the data line driving circuit 101, the sampling circuit 7, and the image signal line 95 are the “image signal supply unit” according to the present invention. For example.

  The scanning line driving circuit 104 is supplied with a Y clock signal CLY, an inverted Y clock signal CLYinv, and a Y start pulse DY. When the Y start pulse DY is input, the scanning line driving circuit 104 sequentially generates a scanning signal at a timing based on the Y clock signal CLY and the inverted Y clock signal CLYinv and outputs the scanning signal to the scanning line 11.

  The data line driving circuit 101 is supplied with an X clock signal CLX, an inverted X clock signal CLXinv, and an X start pulse DX. When the X start pulse DX is input, the data line driving circuit 101 sequentially receives the sampling signal Si (where i = 1, 2,..., N) at a timing based on the X clock signal CLX and the inverted X clock signal XCLXinv. Generated and output to the sampling signal line 97.

  The sampling circuit 7 includes a plurality of sampling TFTs 171 provided for each data line 6. The sampling TFT 171 is composed of, for example, a P-channel or N-channel single-channel TFT. Note that the sampling TFT 171 may be composed of a complementary TFT.

  The source wiring 171S of the sampling TFT 171 is electrically connected to the image signal line 95, the gate wiring 171G of the sampling TFT 171 is electrically connected to the sampling signal line 97, and the drain wiring of the sampling TFT 171. 171 </ b> D is electrically connected to the data line 6. Each of the sampling TFTs 171 receives the image signal VID via the image signal line 95 and also receives the sampling signal Si from the data line driving circuit 101 via the sampling signal line 97 (where i = 1, 2,..., N). Is input, the image signal VID is sampled and applied to each data line 6 as a data signal Di (where i = 1, 2,..., N).

  As shown in FIG. 3, the liquid crystal device 100 according to the present embodiment includes a plurality of pixels 900 and m scanning lines 11 (that is, wiring lines that intersect with each other) in the image display region 10 a of the TFT array substrate 10 (that is, Scanning lines G1, G2,..., Gm) and n data lines 6. Here, m and n are natural numbers, respectively. Furthermore, the liquid crystal device 100 according to the present embodiment includes m shield lines 400 (that is, shield lines SH1, SH2,..., SHm) in the image display region 10a of the TFT array substrate 10. Each of the m scanning lines is formed to extend along the X direction. Each of the n data lines is formed to extend along the Y direction. Each of the m shield lines 400 is provided so as to make a pair with each of the m scan lines 11. That is, the shield line SHi (where i = 1, 2,..., M) is paired with the scanning line Gi (where i = 1, 2,..., M). Each of the m shield lines 400 is formed so as to extend along the X direction, similarly to the m scan lines 11. The shield wire 400 is an example of the “conductive electrode” according to the present invention.

  The pixels 900 are two-dimensionally arranged in a matrix of m rows × n columns in the image display area 10a. More specifically, the pixel 900 is in the first column, the second column,..., The nth column from the left side in the image display region 10a, and the first row, the second row,. Is arranged. That is, the pixel 900 which is a unit display element is provided corresponding to the intersection of the scanning lines G1,..., Gm and the n data lines 6.

  The pixel 900 includes a TFT 30, a liquid crystal capacitor Clc, and a storage capacitor 70.

  The liquid crystal capacitance Clc is a capacitance due to the pixel electrode 9, the counter electrode 21, and the liquid crystal layer 50 (see FIG. 2). The counter electrode 21 is supplied with a predetermined intermediate potential (or “common potential”) Vcom (for example, 7 volts). Specifically, a predetermined intermediate potential is applied to the counter electrode 21 from an external power source through the external circuit connection terminal 102, the routing wiring 90, the vertical conduction terminal 106, and the vertical conduction member 107 described above with reference to FIG. Vcom is supplied. Here, the intermediate potential Vcom is an example of the “reference potential” according to the present invention, and is a fixed potential such as 7 volts (V), for example.

  As will be described later with reference to FIG. 6, in this embodiment, a so-called line inversion driving method is employed, and the image signal VID is higher than the intermediate potential Vcom (for example, 7 volts) at a predetermined cycle. The polarity is inverted between the positive polarity on the side and the negative polarity on the lower side. That is, each pixel 900 has a positive potential (that is, a positive field potential, for example, 7 to 12 volts) and a negative potential (that is, a negative field potential, for example, 2 to 7 volts) alternately. Supplied. More specifically, the image signal VID is supplied to the pixel 900 at a positive potential higher than the intermediate potential Vcom during display corresponding to one scanning line (that is, one horizontal scanning period). While the display corresponding to the next one scanning line is performed subsequently, the potential is reversed so that the pixel 900 is supplied with a negative potential lower than the intermediate potential Vcom. Further, the predetermined cycle in which the polarity of the image signal VID is inverted is not particularly limited, and may be, for example, a period during which display corresponding to m scanning lines is performed (that is, one screen display period).

  The TFT 30 is an N-channel or P-channel TFT. The source of the TFT 30 is electrically connected to the data line 6. The gate of the TFT 30 is electrically connected to the scanning line 11. More specifically, the gate of the TFT 30 of the pixel 900 in the i-th row (where i = 1, 2,..., M) is the i-th scanning line Gi (where i = 1, 2,... m) is electrically connected. The TFT 30 is switched on and off by a scanning signal supplied from the scanning line drive circuit 104. The drain of the TFT 30 is electrically connected to one end of each of the liquid crystal capacitor Clc and the storage capacitor 70.

  The storage capacitor 70 is electrically connected in parallel with the liquid crystal capacitor Clc in order to prevent the held image signal from leaking. One of the pair of capacitor electrodes constituting the storage capacitor 70 is electrically connected to the drain of the TFT 30. The other of the pair of capacitor electrodes constituting the storage capacitor 70 is electrically connected to the shield line 400. More specifically, the other of the pair of capacitor electrodes constituting the storage capacitor 70 is constituted by a part of the shield line 400.

  When the scanning signal is input to the gate of the TFT 30 and the TFT 30 is turned on, the voltage applied to the source of the TFT 30 electrically connected to the data line 6 is applied to and supplied to the liquid crystal capacitor Clc and the storage capacitor 70. The potential of the data signal is maintained. Accordingly, the potential of the data signal supplied to the pixel 900 when image display is performed can be held for a long time. The data signals D1, D2,..., Dn to be written to the data lines 6 may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6. May be.

  A predetermined level of the data signal Di (where i = 1, 2,..., N) written in the liquid crystal constituting the liquid crystal capacitor Clc is held for a certain period. The liquid crystal modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The light transmittance is increased, and light having a contrast corresponding to the image signal is emitted from the image display area 10a of the liquid crystal device 100 as a whole.

  In this embodiment, for the sake of simplicity of explanation, the scanning signals G1, G2,..., Gm are applied to the scanning line 11 in this order in a line-sequential manner, but the scanning signal Gi (however, i = 1, 2,..., M) may be applied to the scanning line 11 in any order.

  The shield potential control circuit 300 supplies a shield potential to each of the m shield lines 400. The shield potential control circuit 300 includes a first operation mode for controlling the shield potential so that the shield line SHi has the same polarity as the data signal written to the pixel 900 corresponding to the scanning line Gi, and m shields. Each of the lines 400 has a second operation mode in which an intermediate potential Vcom is supplied as a shield potential. Whether the shield potential control circuit 300 operates in the first or second operation mode is designated by the selection unit 500 described later. The shield potential is an example of the “conductive electrode potential” according to the present invention.

  The selection unit 500 is provided as a part of an external circuit, for example, and designates in which of the first and second operation modes the shield potential control circuit 300 should operate in accordance with an input from the user.

  As will be described later with reference to FIG. 7, for example, when the liquid crystal device 100 is in a normally white mode, the first operation mode is set as a contrast emphasis mode that emphasizes contrast, and the second operation mode. Is set as a brightness emphasis mode that emphasizes brightness. When the user selects the contrast priority mode, the selection unit 500 designates the first operation mode, and the shield potential control circuit 300 operates in the first operation mode. On the other hand, when the user selects the brightness priority mode, the second operation mode is designated by the selection unit 500, and the shield potential control circuit 300 operates in the second operation mode. Further, for example, when the liquid crystal device 100 is in the normally black mode, the first operation mode is set as the brightness emphasis mode, and the second operation mode is set as the contrast emphasis mode. When the user selects the contrast priority mode, the selection unit 500 designates the second operation mode, and the shield potential control circuit 300 operates in the second operation mode. On the other hand, when the user selects the brightness-oriented mode, the selection unit 500 designates the first operation mode, and the shield potential control circuit 300 operates in the first operation mode.

  That is, the selection unit 500 switches the switch for switching the operation mode of the shield potential control circuit 300 between the first operation mode and the second operation mode according to whether the user places importance on contrast or brightness. Function as.

  Next, a specific configuration of the shield line 400 of the liquid crystal device 100 according to the present embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a plan view showing the configuration of the shield line 400 together with the configuration of the pixel electrode 9, the data line 6, and the scanning line 11. FIG. 5 is a cross-sectional view taken along the line V-V ′ of FIG. 4. In FIG. 4, for convenience of explanation, the illustration of the capacitor electrode 71 shown in FIG. 5 is omitted. In FIG. 5, for convenience of explanation, the liquid crystal layer 50 and the counter electrode 21 are illustrated. Further, in FIG. 5, the scales of the respective layers / members are different from each other in order to make the layers / members recognizable on the drawing.

  4 and 5, the data line 6, the scanning line 11, the shield line 400, and the pixel electrode 9 are provided on the TFT array substrate 10.

  The scanning line 11 is formed on the TFT array substrate 10 so as to extend along the X direction and to overlap the gap region Rc located between the pixel electrodes 9 adjacent to each other in the Y direction. The scanning line 11 is made of, for example, conductive polysilicon, and at least one of refractory metals such as titanium (Ti), chromium (Cr), tungsten (W), tantalum (Ta), and molybdenum (Mo). It is possible to form a single metal containing one metal, an alloy, metal silicide, polysilicide, or a laminate thereof.

  A base insulating film 12 is provided on the upper layer side of the scanning line 11. On the base insulating film 12, a TFT 30 (not shown in FIGS. 4 and 5; see FIG. 3) is provided so as to overlap, for example, the intersection where the data line 6 and the scanning line 11 intersect each other.

  The data line 6 is formed on the interlayer insulating film provided on the upper layer side of the TFT 30 so as to extend along the Y direction (see FIG. 4, not shown in FIG. 5). The data line 6 is made of a conductive material such as aluminum (Al). An interlayer insulating film 42 is provided on the upper layer side of the data line 6. A storage capacitor 70 is provided on the interlayer insulating film 42.

  The storage capacitor 70 includes a capacitor electrode 71 provided on the interlayer insulating film 42, a dielectric film 72 provided on the upper layer side of the capacitor electrode 71, and a shield line 400 provided on the upper layer side of the dielectric film 72. It is composed of The capacitor electrode 71 is an example of the “pixel potential side capacitor electrode” according to the present invention, and is provided in an island shape for each pixel 900 so as to face a part of the shield line 400 through the dielectric film 72. Yes. The capacitor electrode 71 is electrically connected to the pixel electrode 9 through a contact hole that penetrates the dielectric film 72 and the interlayer insulating film 43. The dielectric film 72 is made of a transparent dielectric material such as silicon nitride. The dielectric film 72 is formed so as to overlap substantially the entire image display area 10a. Since the dielectric film 72 is made of a transparent dielectric material such as silicon nitride, for example, even if the dielectric film 72 is formed widely in the image display area 10a, the light transmittance in the opening area is almost or practically practiced. There is no decline at all.

  Here, particularly in this embodiment, the shield line 400 constitutes a capacitor line for supplying a predetermined potential to the storage capacitor 70. That is, in this embodiment, in particular, the shield line 400 has a portion functioning as one of the pair of capacitor electrodes constituting the storage capacitor 70 of each pixel 900 and a predetermined potential (this embodiment) on the one capacitor electrode. , A portion functioning as a capacitor line for supplying a shield potential). Therefore, the stacked structure on the substrate can be simplified as compared with the case where the capacitor line is provided separately from the shield line 400.

  The shield line 400 is formed on the dielectric film 72 so as to extend along the X direction and to overlap the gap region Rc located between the pixel electrodes 9 adjacent to each other in the Y direction, in the same manner as the scanning line 11. Has been. The shield line 400 is provided so as to overlap the scanning line 11. The shield line 400 is made of a conductive material such as Al. An interlayer insulating film 43 is provided on the upper layer side of the shield line 400. A plurality of pixel electrodes 9 are provided in a matrix on the interlayer insulating film 43.

  The pixel electrode 9 is disposed in each of the pixels 900 and is formed such that the data lines 6 and the scanning lines 11 are arranged in a grid pattern at the boundary (see FIG. 4). The pixel electrode 9 is made of a transparent conductive material such as ITO. On the upper side of the pixel electrode 9, an alignment film subjected to a predetermined alignment process such as a rubbing process is provided.

  On the other hand, the counter substrate 20 (see FIG. 2) is provided with a counter electrode 21 so as to face the plurality of pixel electrodes 9 with the liquid crystal layer 50 interposed therebetween. The counter electrode 21 is made of a transparent conductive material such as ITO, for example, like the pixel electrode 9.

  Next, the operation of the shield potential control circuit 300 will be described with reference to FIGS. 6 and 7 in addition to FIGS.

  FIG. 6 is a timing chart showing changes with time in the potential of the shield line SHi when the shield potential control circuit 300 operates in the first operation mode. In addition to the potential of the shield line 400, FIG. 6 shows the potential of the scanning line 11 and the potential of the image signal VID.

  6, when the liquid crystal device 100 is operated, pulsed scanning signals are supplied in this order to the scanning lines G1, G2,..., Gm, and the scanning lines G1, G2,. Only the potential for turning on the TFT 30 (for example, 15.5 volts) is set. The scanning lines G1,..., Gm are maintained at a potential (for example, 0 volts) for turning off the TFT 30 in a period other than the period in which the scanning signal is supplied.

  In the present embodiment, a so-called line inversion driving method is employed, and the image signal VID is inverted in polarity at a predetermined cycle between a positive polarity on the higher side and a negative polarity on the lower side with respect to a reference potential (for example, 7 volts). Is done. In other words, a positive potential (that is, a positive field potential, for example, 12 volts) and a negative potential (that is, a negative field potential, for example, 2 volts) are alternately supplied to each pixel 900. That is, the pixel electrode 9 of each pixel 900 has a positive potential (that is, a positive field potential, for example, 7 to 12 volts) and a negative potential (that is, a negative field potential, for example, 2 to 7 volts). And are supplied alternately. More specifically, during the display corresponding to one scanning line 11 (that is, one horizontal scanning period), the image signal VID has a positive potential (that is, higher than the intermediate potential Vcom) in the pixel 900. In contrast, during display corresponding to the next one scanning line, the pixel 900 is supplied with a negative potential (potential lower than the intermediate potential Vcom). The polarity of the potential is inverted. In the example of FIG. 6, in a period during which a scanning signal is supplied to the scanning line G1 (that is, a period during which the scanning line G1 is set to a potential for turning on the TFT 30), the data signals D1, D2,. Is a positive potential, and during a period in which the scanning signal is supplied to the scanning line G2, the data signals D1, D2,..., Dn are negative potentials and a period in which the scanning signal is supplied to the scanning line G3. The data signals D1, D2,..., Dn are positive potentials, and the data signals D1, D2,..., Dn are negative potentials during the period when the scanning signal is supplied to the scanning line G4. .

  3 and 6, particularly in the present embodiment, in the first operation mode, the shield potential control circuit 300 causes the shield line SHi to have the same polarity as the data signal written to the pixel 900 corresponding to the scanning line Gi. The shield potential is controlled to have. That is, as shown in FIG. 6, the shield line SHi (where i = 1, 2,..., M) is scanned by the shield line SHi paired by the shield potential supplied from the shield potential control circuit 300. The potential is the same as that of the data signal written to the pixel 900 corresponding to the line Gi (that is, the pixel 900 in the i-th row). In the example of FIG. 6, in response to the positive data signals D1, D2,..., Dn being written to the pixels 900 corresponding to the scanning line G1 (that is, the pixels 900 in the first row), A positive potential is supplied as a shield potential to the shield line SH1 at the timing when the scanning signal is supplied. Thereafter, until the timing when the scanning signal is next supplied to the scanning line G1 (that is, before the negative polarity data signals D1, D2,..., Dn are written in the pixels 900 corresponding to the scanning line G1), the shield line SH1. The shield potential supplied to is kept positive. In response to the negative data signals D1, D2,..., Dn being written to the pixels 900 corresponding to the scanning line G2 (that is, the pixels 900 in the second row), the scanning signal is supplied to the scanning line G2. At the timing, a negative potential is supplied as a shield potential to the shield line SH2. Thereafter, until the timing when the scanning signal is next supplied to the scanning line G2 (that is, before the positive polarity data signals D1, D2,..., Dn are written to the pixels 900 corresponding to the scanning line G2), the shield line SH2 The shield potential supplied to is kept positive.

  In FIG. 5, when the shield potential control unit 300 operates in such a first operation mode, the voltage applied to the liquid crystal layer 50 in the pixel electrode region Rp provided with the pixel electrode 9 and the gap region Rc. The difference can be reduced. Here, for example, when an intermediate potential Vcom (for example, 7 volts) is supplied as a shield potential to each of the m shield lines 400, both the shield line 400 and the counter electrode 21 have the intermediate potential Vcom, and the shield Since the potential difference between the line 400 and the counter electrode 21 becomes zero, the voltage applied to the portion of the liquid crystal layer 50 located in the gap region Rc is applied to the portion of the liquid crystal layer 50 located in the pixel electrode region Rp. The voltage tends to be lower than

  That is, in the first operation mode, the shield potential control unit 300 controls the shield potential so that the shield line SHi has the same polarity as the potential of the pixel electrode 9 corresponding to the scanning line Gi. The difference in voltage applied to the liquid crystal layer 50 can be reduced between the region Rp and the gap region Rc.

  Therefore, for example, when the liquid crystal constituting the liquid crystal layer 50 is a TN liquid crystal, for example, and the liquid crystal device 100 is a normally white mode liquid crystal device, the blackness in the gap region Rc can be increased, and the display image The contrast can be improved. Further, for example, when the liquid crystal constituting the liquid crystal layer 50 is, for example, VA liquid crystal or the like, and the liquid crystal device 100 is a normally black mode liquid crystal device, whiteness (in other words, brightness) in the gap region Rc. And the brightness of the display image can be improved.

  Further, particularly in the present embodiment, the shield potential control circuit 300 supplies the intermediate potential Vcom as a shield potential to each of the m shield lines 400 in the second operation mode. Therefore, when the shield potential control circuit 300 operates in the second operation mode, the voltage applied to the portion of the liquid crystal layer 50 located in the gap region Rc is changed to the portion of the liquid crystal layer 50 located in the pixel electrode region Rp. It can be made lower than the voltage applied to. Therefore, for example, when the liquid crystal device 100 is a normally white mode liquid crystal device, the whiteness in the gap region Rc can be increased, and the brightness of the display image can be improved. For example, when the liquid crystal device 100 is a normally black mode liquid crystal device, the blackness in the gap region Rc can be increased, and the contrast of the display image can be improved.

  FIG. 7 is a table showing a comparison between the potential of the shield line 400 when the brightness priority mode is specified and the potential of the shield line 400 when the contrast priority mode is specified. FIG. 7A shows a case where the liquid crystal device 100 is a normally white mode liquid crystal device, and FIG. 7B shows a case where the liquid crystal device 100 is a normally black mode liquid crystal device.

  As shown in FIG. 7A, when the liquid crystal device 100 is a normally white mode liquid crystal device, the selection unit 500 sets the second operation mode as the brightness priority mode, as described above. The first operation mode is set as the contrast priority mode. That is, when the user selects the brightness priority mode in the selection unit 500, the selection unit 500 designates the second operation mode as the operation mode of the shield potential control circuit 300. Accordingly, the shield potential control circuit 300 operates in the second operation mode, so that the m shield lines 400 are negative regardless of the polarity of the image signal VID (that is, even if the data signal is a positive field). Even in the field), the intermediate potential is Vcom. Thereby, as described above, the brightness of the display image can be improved. On the other hand, when the user selects the contrast-oriented mode in the selection unit 500, the selection unit 500 designates the first operation mode as the operation mode of the shield potential control circuit 300. Accordingly, the shield potential control circuit 300 operates in the first operation mode, so that each of the m shield lines 400 has the same polarity as the potential of the pixel electrode 9 corresponding to the paired scanning lines 11. In other words, when the data signal written to the pixel 900 corresponding to the paired scanning lines 11 is a positive field (that is, positive polarity), the potential is set to a positive potential and the paired scanning lines 11 are used. When the data signal written to the pixel 900 corresponding to is a negative field (that is, negative polarity), the potential is negative. Thereby, as described above, the contrast of the display image can be improved.

  On the other hand, as shown in FIG. 7B, when the liquid crystal device 100 is a normally black mode liquid crystal device, the selection unit 500 sets the first operation mode as the brightness-oriented mode as described above. Then, the second operation mode is set as the contrast priority mode. That is, when the user selects the brightness priority mode in the selection unit 500, the selection unit 500 designates the first operation mode as the operation mode of the shield potential control circuit 300. Accordingly, the shield potential control circuit 300 operates in the first operation mode, so that the m shield lines 400 correspond to the pixel electrodes corresponding to the scanning lines 11 that form a pair. If the data signal written to the pixel 900 corresponding to the scanning line 11 forming a pair is a positive field (ie, positive polarity), the potential of the positive polarity is If the data signal written to the pixel 900 corresponding to the pair of scanning lines 11 is a negative field (that is, negative polarity), the potential is negative. Thereby, as described above, the brightness of the display image can be improved. On the other hand, when the user selects the contrast priority mode in the selection unit 500, the selection unit 500 designates the second operation mode as the operation mode of the shield potential control circuit 300. Accordingly, the shield potential control circuit 300 operates in the second operation mode, so that the m shield lines 400 are negative regardless of the polarity of the image signal VID (that is, even if the data signal is a positive field). Even in the field), the intermediate potential is Vcom. Thereby, as described above, the contrast of the display image can be improved.

  As described above, according to the liquid crystal device 100 according to the present embodiment, it is possible to perform display in accordance with whether the user attaches importance to contrast or brightness. That is, when the user attaches importance to the contrast of the display image (that is, when the contrast emphasis mode is selected), the contrast of the display image can be reliably increased and the user attaches importance to the brightness of the display image. In this case (that is, when the brightness priority mode is selected), the brightness of the display image can be reliably increased.

  As described above, according to the liquid crystal device 100 according to the present embodiment, the contrast and brightness of the display image can be selectively increased, and high-quality display can be performed.

Second Embodiment
A liquid crystal device according to a second embodiment will be described with reference to FIGS.

  FIG. 8 is a block diagram showing an electrical configuration of the liquid crystal device 100b according to the present embodiment. FIG. 9 is a cross-sectional view showing the configuration of the shield line 420 and the storage capacitor 70 of the liquid crystal device 100b according to the present embodiment, and is a cross-sectional view having the same concept as in FIG. 8 and 9, the same reference numerals are given to the same components as those according to the first embodiment shown in FIGS. 1 to 7, and description thereof will be omitted as appropriate.

  8 and 9, the liquid crystal device 100b according to the second embodiment is described above in that the shield line 420 is provided in place of the shield line 400 in the first embodiment described above, and the capacitor line 600 is further provided. Unlike the liquid crystal device 100 according to the first embodiment, the other configuration is substantially the same as the liquid crystal device 100 according to the first embodiment described above.

  The capacitor line 600 is formed on the dielectric film 72 so as to extend along the X direction and to overlap the gap region Rc located between the pixel electrodes 9 adjacent to each other in the Y direction, in the same manner as the scanning line 11. Has been. An intermediate potential Vcom is supplied to the capacitor line 600. A part of the capacitor line 600 is opposed to the capacitor electrode 71 through the dielectric film 72 and is configured as a fixed potential side capacitor electrode of the storage capacitor 70. That is, in the first embodiment described above, the storage capacitor 70 is composed of the capacitor electrode 71, the dielectric film 72, and a part of the shield line 400, whereas in the second embodiment, the storage capacitor 70 is formed. Reference numeral 70 denotes a capacitor electrode 71, a dielectric film, and a part of the capacitor line 600. The capacitor line 600 is made of a conductive material such as Al, for example. An interlayer insulating film 43 is provided on the upper layer side of the capacitor line 600.

  The shield line 420 is formed on the interlayer insulating film 43 so as to extend along the X direction and to overlap with the gap region Rc located between the pixel electrodes 9 adjacent to each other in the Y direction, as in the scanning line 11. Has been. The shield wire 420 is made of a conductive material such as Al. An interlayer insulating film 44 is provided on the upper layer side of the shield line 420. A plurality of pixel electrodes 9 are provided in a matrix on the interlayer insulating film 44.

  Also in the liquid crystal device 100b according to the second embodiment configured as described above, the shield potential control circuit 300 has the first operation mode and the second operation mode, so that the liquid crystal device 100 according to the first embodiment described above. In general, the contrast and brightness of the display image can be selectively increased, and high-quality display can be performed.

<Electronic equipment>
Next, the case where the above-described liquid crystal device, which is an electro-optical device, is applied to various electronic devices will be described.

  FIG. 10 is a plan view showing a configuration example of the projector. Hereinafter, a projector using the liquid crystal device as a light valve will be described.

  As shown in FIG. 10, a lamp unit 1102 including a white light source such as a halogen lamp is provided inside the projector 1100. The projection light emitted from the lamp unit 1102 is separated into three primary colors of RGB by four mirrors 1106 and two dichroic mirrors 1108 arranged in the light guide 1104, and serves as a light valve corresponding to each primary color. The light enters the liquid crystal panels 1110R, 1110B, and 1110G.

  The configurations of the liquid crystal panels 1110R, 1110B, and 1110G are the same as those of the liquid crystal device described above, and are driven by R, G, and B primary color signals supplied from the image signal processing circuit. The light modulated by these liquid crystal panels enters the dichroic prism 1112 from three directions. In the dichroic prism 1112, R and B light is refracted at 90 degrees, while G light travels straight. Therefore, as a result of the synthesis of the images of the respective colors, a color image is projected onto the screen or the like via the projection lens 1114.

  Here, paying attention to the display images by the liquid crystal panels 1110R, 1110B, and 1110G, the display image by the liquid crystal panel 1110G needs to be horizontally reversed with respect to the display images by the liquid crystal panels 1110R and 1110B.

  In addition, since light corresponding to each primary color of R, G, and B is incident on the liquid crystal panels 1110R, 1110B, and 1110G by the dichroic mirror 1108, it is not necessary to provide a color filter.

  In addition to the electronic device described with reference to FIG. 10, a mobile personal computer, a mobile phone, a liquid crystal television, a viewfinder type, a monitor direct-view type video tape recorder, a car navigation device, a pager, an electronic device Examples include notebooks, calculators, word processors, workstations, videophones, POS terminals, and devices with touch panels. Needless to say, the present invention can be applied to these various electronic devices.

  In addition to the liquid crystal devices described in the above embodiments, the present invention includes a reflective liquid crystal device (LCOS), a plasma display (PDP), a field emission display (FED, SED), an organic EL display, and a digital micromirror device. (DMD), electrophoresis apparatus and the like are also applicable.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification, and an electro-optical device with such a change. In addition, an electronic apparatus including the electro-optical device is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 6 ... Data line, 7 ... Sampling circuit, 9 ... Pixel electrode, 10 ... TFT array substrate, 10a ... Image display area, 11 ... Scanning line, 20 ... Counter substrate, 21 ... Counter electrode, 30 ... TFT, 50 ... Liquid crystal layer 95, image signal lines, 101, data line driving circuit, 104, scanning line driving circuit, 400, 420 ... shield line, 300 ... shield potential control circuit, 500 ... selection section, 600 ... capacitance line.

Claims (6)

A data line and a scanning line provided on the substrate so as to cross each other;
A pixel electrode provided on the substrate corresponding to the intersection of the data line and the scanning line;
A counter electrode provided to face the pixel electrode and supplied with a predetermined reference potential;
Provided between the substrate and the pixel electrode so as to overlap the scanning line, and to overlap with a region including a gap region located between adjacent pixel electrodes in the extending direction of the data line. A conductive electrode;
An image signal supply unit that supplies an image signal whose polarity is inverted every predetermined period with respect to the reference potential,
A conductive electrode potential supply unit for supplying a conductive electrode potential to the conductive electrode,
A first operation mode for controlling the conductive electrode potential so that the conductive electrode potential supply unit has a potential of the same polarity as the image signal supplied to the pixel electrode;
And a second operation mode for controlling the conductive electrode potential so that the conductive electrode has the same potential as the reference potential.   The electro-optical device according to claim 1, further comprising: a designation unit that designates in which operation mode of the first and second operation modes the conductive electrode potential supply unit should operate. The electro-optical device is a normally white mode liquid crystal device,
The specification unit sets the first operation mode as a contrast emphasis mode in which contrast is important, and sets the second operation mode as a brightness emphasis mode in which brightness is important. Item 5. The electro-optical device according to Item 2. The electro-optical device is a normally black mode liquid crystal device,
The specification unit sets the first operation mode as a brightness emphasis mode in which brightness is important, and sets the second operation mode as a contrast emphasis mode in which contrast is important. Item 5. The electro-optical device according to Item 2.   A pixel potential side capacitor electrode disposed between the substrate and the conductive electrode so as to face the conductive electrode through a dielectric film, and electrically connected to the pixel electrode; The electro-optical device according to claim 1, wherein the electrode forms a capacitive line.   An electronic apparatus comprising the electro-optical device according to claim 1.

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