JP2009204898A - Electrooptical device, electronic equipment and driving method of electrooptical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrooptical device which permits a variety of image display such as halftone display even in a two-gradation driving system, to provide electronic equipment provided with such an electrooptical device and to provide a driving method of the electrooptical device. <P>SOLUTION: When the electrooptical device is used for a head-up display, a pixel 100a includes sub pixels 100b(R), 100b(G) which are subjected to two-gradation drive, and the sub pixels 100b(R), 100b(G) are composed of a plurality of split sub pixels (first split sub pixel R1 for red, second split sub pixel R2 for red, first split sub pixel G1 for green and second split sub pixel G2 for green) which are subjected to two-gradation drive independently of one another. As the result, the electrooptical device can be set such that, even in two-gradation drive, all split sub pixels are in the non-lighting state, a part among split sub pixels is in the non-lighting state and other split sub pixels are in the lighting state or all of split sub pixels are in the lighting state. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electro-optical device capable of displaying various types of information in color, an electronic apparatus including the electro-optical device, and a driving method of the electro-optical device.

In an electro-optical device such as a liquid crystal device or an organic electroluminescence device, a plurality of pixels are arranged in a predetermined direction. Among such electro-optical devices, for example, when performing color display with a liquid crystal device, each of the plurality of pixels is configured by three sub-pixels corresponding to red, green, and blue, and the three sub-pixels are respectively In general, full color display is performed by driving with multiple gradations such as 256 gradations (see Patent Document 1).
JP-A-2-298916

  In recent years, electro-optical devices have been used in various electronic devices such as direct-view display devices or projection display devices. Of the projection display devices, a display device that projects and displays various images on the windshield glass of the vehicle is called a head-up display (HUD / Head Up Display). There is an advantage that a person can visually recognize information without dropping his / her line of sight. In an apparatus that displays such information, simplification of the apparatus configuration is desired rather than displaying a full-color and high-quality image.

  Here, the present inventor proposes a method in which a plurality of pixels are each composed of a plurality of sub-pixels that emit light of different colors, and each of the plurality of sub-pixels is driven with two gradations. It is. This configuration has an advantage that the configuration of the data line driving circuit and the image processing circuit can be simplified.

  However, such a two-tone drive method has a problem that the product value is low because the expression color of the image is too limited.

  Accordingly, an object of the present invention is to provide an electro-optical device capable of displaying various images such as halftone display even with a two-tone drive method, an electronic apparatus including such an electro-optical device, and an electric device. An object of the present invention is to provide a method for driving an optical device.

  In order to solve the above problem, in the present invention, in the electro-optical device including a plurality of pixels, each of the plurality of pixels includes a plurality of sub-pixels that emit light of different colors, and the plurality of sub-pixels. At least one of the sub-pixels includes a plurality of divided sub-pixels that emit light of the same color, and each of the plurality of divided sub-pixels is independently driven with two gradations. .

  According to the present invention, in the driving method of the electro-optical device including a plurality of pixels, each of the plurality of pixels is provided with a plurality of subpixels that emit light of different colors, and the plurality of subpixels Among these, at least one sub-pixel is provided with a plurality of divided sub-pixels that emit light of the same color, and each of the plurality of divided sub-pixels is independently driven with two gradations.

  In the present invention, “the plurality of pixels are each composed of a plurality of sub-pixels that emit light of different colors” means that the pixels are sub-pixels that emit white light, red (R), green ( G) and sub-pixels that emit colored light such as blue (B). The “same color light” includes a case where each of the divided sub-pixels emits white light in addition to emitting colored light such as red (R), green (G), and blue (B). Meaning.

  In the present invention, since the two-gradation method is adopted, it is possible to simplify the configuration of the driving circuit and the image processing circuit for driving the pixels. In addition, at least one of the plurality of sub-pixels includes a plurality of divided sub-pixels that are driven with two gradations independently of each other. All of the divided sub-pixels can be turned off, some of the plurality of divided sub-pixels can be turned off, others can be turned on, and all of the plurality of divided sub-pixels can be turned on. Therefore, even if the two-tone driving method is used, a variety of image display such as halftone display is possible.

  In the present invention, it is preferable that each of the plurality of sub-pixels emit different colored light, for example, colored light such as red (R), green (G), and blue (B). According to such a configuration, various color displays can be performed.

  In the present invention, it is preferable that one pixel is composed of two sub-pixels. In the present invention, since a variety of image displays can be performed even with the two-tone drive method, a variety of image displays can be performed even when one pixel is constituted by two sub-pixels.

  In the present invention, it is preferable that each of the plurality of sub-pixels includes the plurality of divided sub-pixels. If comprised in this way, a more various image display can be performed.

  In the present invention, it is preferable that one subpixel is constituted by two divided subpixels. In the present invention, a variety of image displays can be performed even with the two-tone drive method, and therefore a variety of image displays can be performed even when one subpixel is constituted by two divided subpixels.

  In the present invention, a configuration in which the plurality of divided sub-pixels have the same luminance characteristic in the sub-pixel can be employed.

  In the present invention, it is preferable that the plurality of divided sub-pixels have different luminance characteristics in the sub-pixel. With this configuration, the display form of the image changes depending on which of the plurality of divided sub-pixels is turned on, so that even a two-tone drive system can display a wide variety of images. Can do.

  In the present invention, in order to realize a configuration in which the plurality of divided sub-pixels have different luminance characteristics, in the sub-pixel, the plurality of divided sub-pixels include color filters having different densities. A configuration can be employed. In the subpixel, the plurality of divided subpixels may have different light emission areas.

  When the electro-optical device to which the present invention is applied is a liquid crystal device, an element substrate on which pixel electrodes corresponding to the sub-pixels are formed, a counter substrate disposed opposite to the element substrate, the element substrate, and the counter substrate And a liquid crystal held between them.

  The electro-optical device to which the present invention is applied can be used for a direct-view display device (electronic device) such as a mobile phone, an electronic notebook, a viewfinder type, a POS terminal, a touch panel, or a projection display device such as a head-up display. It can be used for (electronic equipment). In this case, the projection display device projects a light source that supplies light to the electro-optical device and display light obtained by optically modulating the light emitted from the light source by the electro-optical device toward a projection surface. And an optical system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the present invention is applied to an active matrix liquid crystal device as an electro-optical device. In the following description, an electro-optical device used for a head-up display (projection display device / electronic apparatus) will be mainly described. In the drawings referred to in the following description, the scales are different for each layer and each member so that each layer and each member have a size that can be recognized on the drawing.

[Basic configuration of head-up display]
FIG. 1 is an explanatory diagram schematically illustrating a basic configuration of a head-up display as an example of an electronic apparatus in which an electro-optical device to which the present invention is applied is mounted.

  A head-up display 1000 shown in FIG. 1 includes a backlight device 110 (light source) using an LED, a cold cathode ray tube, an electroluminescence element, and the like, an electro-optical device 100 described later, and a mirror 120 (optical system). The white light emitted from the backlight device 110 is light-modulated by the electro-optical device 100 and emitted from the electro-optical device 100 toward the mirror 120 as display light. The display light reflected by the mirror 120 is projected onto the windshield glass 130 (projected surface).

  The head-up display 1000 performs simple navigation display, speed display, and the like. At that time, since sufficient information can be displayed even with a small number of colors, the head-up display 1000 has a special feature that unlike an ordinary full-color display device, an image can be displayed with a small number of colors. Yes.

  Moreover, the head-up display 1000 may be configured as a night vision. In this case, an image obtained by capturing the front of the vehicle such as an infrared camera is displayed at night, and when the presence of a passerby is recognized, a warning is given in red in the image. In such an application, the head-up display 1000 has a special feature that, for example, a green image display and a warning display in red may be performed, unlike a normal full-color display device.

  Therefore, in the present invention, the electro-optical device 100 is configured as described below. Although FIG. 1 shows an example in which a transmissive liquid crystal device is used as the electro-optical device 100, a reflective liquid crystal device may be used.

[Embodiment 1]
(overall structure)
FIG. 2 is a block diagram showing an electrical configuration of the electro-optical device to which the present invention is applied. As shown in FIG. 2, the electro-optical device 100 includes a liquid crystal panel 100p and an image processing circuit 250, and the image processing circuit 250 is mounted on a flexible substrate (not shown) connected to the liquid crystal panel 100p. It is comprised by the IC etc. which were made.

  The liquid crystal panel 100p includes a pixel array region 10b in which a plurality of pixels 100a are arrayed in a central region. As will be described in detail later, in the electro-optical device 100 of the present embodiment, each of the plurality of pixels 100a includes a plurality of sub-pixels that emit light of different colors. In this embodiment, each of the plurality of pixels 100a includes two subpixels, and one of the two subpixels is a subpixel 100b (R) that emits red (R) light. The other sub-pixel is a sub-pixel 100b (G) that emits green (G) light.

  In the present embodiment, the sub-pixel 100b (R) that emits red (R) light includes the red first divided sub-pixel R1 and the red second divided sub-pixel R2, and the green The sub-pixel 100b (G) that emits the light of (G) includes a first divided sub-pixel G1 for green and a second divided sub-pixel G2 for green.

  In the liquid crystal panel 100p, on the element substrate 10 described later, a plurality of data lines 6a and a plurality of scanning lines 3a extend vertically and horizontally inside the pixel array region 10b, and are arranged at positions corresponding to the intersections thereof. The divided sub-pixels (the first divided sub-pixel R1 for red, the second divided sub-pixel R2 for red, the first divided sub-pixel G1 for green, and the second divided sub-pixel G2 for green) are configured. . In each of the plurality of divided sub-pixels, a thin film transistor 30 as a pixel switching element and a pixel electrode 9a are formed in a one-to-one relationship. The data line 6 a is electrically connected to the source of the thin film transistor 30, the scanning line 3 a is electrically connected to the gate of the thin film transistor 30, and the pixel electrode 9 a is electrically connected to the drain of the thin film transistor 30.

  In each divided sub-pixel (the first divided sub-pixel R1 for red, the second divided sub-pixel R2 for red, the first divided sub-pixel G1 for green, and the second divided sub-pixel G2 for green), the pixel electrode 9a is opposed to a common electrode formed on a counter substrate, which will be described later, via a liquid crystal and constitutes a liquid crystal capacitor 50a. Each divided subpixel is provided with a storage capacitor 60 in parallel with the liquid crystal capacitor 50a in order to prevent the gradation signal held in the liquid crystal capacitor 50a from leaking. In this embodiment, in order to form the storage capacitor 60, the capacitor line 3b is formed in parallel with the scanning line 3a, and the capacitor line 3b is connected to a common potential line (not shown) and has a predetermined potential. Is held in. The storage capacitor 60 may be formed between the preceding scanning line 3a.

(Configuration of drive circuit)
In the element substrate 10, a data line driving circuit 210 and a scanning line driving circuit 220 are configured in the outer region of the pixel array region 10 b. The scanning line driving circuit 220 is electrically connected to each scanning line 3a, and sequentially supplies scanning signals to each scanning line 3a.

  The data line driving circuit 210 is electrically connected to one end of each data line 6a, and a voltage gradation signal (image signal) corresponding to the image data Ds supplied from the image processing circuit 250 is supplied to each data line 6a. Supply sequentially.

  That is, when the data Df is input from the upper control unit, the image processing circuit 250 generates the image data Ds from the lookup table 251 based on the data Df, and temporarily stores the image data Ds in the frame memory 253. The image data Ds is sequentially supplied to the data line driving circuit 210 at a predetermined timing.

  The data line driving circuit 210 includes a sampling signal output circuit 211 having a shift register and a latch circuit, and a voltage selection circuit 213. In the data line driving circuit 210, a signal output from the sampling signal output circuit 211 is provided. Based on the above, a predetermined voltage is selected for each data line 6a in the voltage selection circuit 213, and a signal of such voltage is supplied to each data line 6a as a gradation signal (image signal).

  In this embodiment, a two-tone driving method is adopted as a driving method for each divided pixel. For this reason, the gradation signal supplied to each data line 6a is two voltages corresponding to ON (lighting) or OFF (lighting off). Therefore, the voltage selection circuit 213 includes only gradation voltage lines corresponding to two voltage levels. Note that when the inversion driving method is employed, the polarity of the voltage selected by the voltage selection circuit 213 is inverted depending on the type of the inversion driving method, so that the number of gradation voltages increases. The number of gradation voltage lines is extremely small as compared with a normal liquid crystal device for full color display.

(Specific configuration of liquid crystal panel and element substrate)
FIGS. 3A and 3B are a plan view of the liquid crystal panel 100p of the electro-optical device 100 to which the present invention is applied as viewed from the side of the counter substrate together with each component, and a cross-sectional view thereof taken along line HH ′. . As shown in FIGS. 3A and 3B, in the liquid crystal panel 100p of the electro-optical device 100, the element substrate 10 and the counter substrate 20 are attached to each other with a sealant 107 through a predetermined gap. The sealing material 107 is arranged along the edge of the counter substrate 20. The sealing material 107 is an adhesive made of a photo-curing resin, a thermosetting resin, or the like, and is mixed with a gap material such as glass fiber or glass beads for setting the distance between both substrates to a predetermined value.

  In the element substrate 10, a data line driving circuit 210 and a plurality of terminals 230 are formed along one side of the element substrate 10 in the outer region of the sealing material 107, and scanning line driving is performed along two sides adjacent to the one side. A circuit 220 is formed. In at least one corner of the counter substrate 20, a vertical conductive material 109 is formed for electrical conduction between the element substrate 10 and the counter substrate 20.

  As will be described in detail later, pixel electrodes 9 a are formed in a matrix on the element substrate 10. On the other hand, a frame 108 made of a light-shielding material is formed in the inner area of the sealing material 107 on the counter substrate 20, and the inner side is an image display area 10 a. In the counter substrate 20, a light shielding film 23 called a black matrix (or black stripe) is formed in a region facing the vertical and horizontal boundary regions of the pixel electrode 9 a of the element substrate 10, and the upper layer side will be described later. A color filter, a planarizing film, a common electrode 21, and an alignment film are formed. In the pixel array area 10b, a dummy pixel may be configured in an area overlapping with the frame 108. In this case, the area excluding the dummy pixel in the pixel array area 10b is used as the image display area 10a. become.

  Although not shown, in the electro-optical device 100, the type of the liquid crystal 50 to be used, that is, the TN (twisted nematic) mode, STN (STN) is provided on the light incident side surface or the light emission side of the counter substrate 20 and the element substrate 10. A polarizing film, a retardation film, a polarizing plate, and the like are arranged in a predetermined direction according to an operation mode such as a super TN mode and a normally white mode / normally black mode.

(Specific configuration of each pixel)
4A and 4B are plan views of adjacent pixels in the element substrate 10 used in the electro-optical device 100 to which the present invention is applied, and electro-optics at positions corresponding to the AA ′ line. It is sectional drawing when the apparatus 100 is cut | disconnected.

  As shown in FIGS. 4A and 4B, the element substrate 10 is provided with a base protective film 12 made of a silicon oxide film or the like on the surface of a translucent substrate 10d made of glass or the like. On the surface side, an N-channel thin film transistor 30 is formed at a position adjacent to the pixel electrode 9a. The thin film transistor 30 is an LDD in which a channel formation region 1a ′, a low concentration source region 1b, a high concentration source region 1d, a low concentration drain region 1c, and a high concentration drain region 1e are formed on an island-shaped semiconductor film 1a. Lightly Doped Drain) structure.

The semiconductor film 1a is a polysilicon film that is polycrystallized by laser annealing or lamp annealing after an amorphous silicon film is formed on the element substrate 10. The low-concentration source region 1b and the low-concentration drain region 1c are low-concentration N-type, for example, with a dose of about 0.1 × 10 ¹³ / cm ² to about 10 × 10 ¹³ / cm ^{2 using} the scanning line 3a as a mask. This is a semiconductor region formed by introducing impurity ions (phosphorus ions), and the high concentration source region 1d and the high concentration drain region 1e are about 0.1 × 10 ¹⁵ / cm ² to about 10 using a resist mask. This is a semiconductor region formed by introducing high-concentration N-type impurity ions (phosphorus ions) at a dose of × 10 ¹⁵ / cm ² .

  On the upper layer side of the thin film transistor 30, interlayer insulating films 7 and 8 are formed. A data line 6 a is formed on the surface of the interlayer insulating film 7, and the data line 6 a is electrically connected to the high concentration source region 1 d via a contact hole 7 a formed in the interlayer insulating film 7. A translucent pixel electrode 9 a made of an ITO (Indium Tin Oxide) film is formed on the surface of the interlayer insulating film 8. The pixel electrode 9 a is electrically connected to the drain electrode 6 b through the contact hole 8 a formed in the interlayer insulating film 8, and the drain electrode 6 b is connected to the contact hole formed in the interlayer insulating film 7 and the gate insulating film 2. 7b is electrically connected to the high concentration drain region 1e. An alignment film 16 made of a polyimide film is formed on the surface side of the pixel electrode 9a. Further, the extension portion 1f (lower electrode) extending from the high-concentration drain region 1e has a capacitance in the same layer as the scanning line 3a through an insulating film (dielectric film) formed simultaneously with the gate insulating film 2. The storage capacitor 60 is configured by the line 3b facing as an upper electrode. In this embodiment, the scanning line 3a and the capacitor line 3b are formed of a single layer film or a laminated film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, or a tantalum film. The data line 6a and the drain electrode 6b are also formed of a single layer film or a laminated film such as a molybdenum film, an aluminum film, a titanium film, a tungsten film, or a tantalum film.

  The element substrate 10 and the counter substrate 20 configured as described above are arranged so that the pixel electrode 9a and the common electrode 21 face each other, and the sealing material 107 (see FIG. ) And (b)), a liquid crystal 50 as an electro-optical material is sealed in a space surrounded by The liquid crystal 50 takes a predetermined alignment state by the alignment films 16 and 26 in a state where an electric field from the pixel electrode 9a is not applied. The liquid crystal 50 is made of, for example, one or a mixture of several types of nematic liquid crystals.

  In the electro-optical device 100 having such a configuration, one divided sub-pixel (the first divided sub-pixel R1 for red, the second divided sub-pixel R2 for red, the green-colored sub-pixel R2) corresponds to one pixel electrode 9a. A first divided sub-pixel G1 and a second divided sub-pixel G2 for green) are configured.

  In configuring such a divided sub-pixel, in the counter substrate 20, first, on the surface of the translucent substrate 20 b made of glass or the like, a region facing the boundary region of the divided sub-pixels of different colors (first for red). Black stripes along the boundary region between the divided sub-pixel R1 and the second divided sub-pixel G2 for green and the boundary region between the second divided sub-pixel R2 for red and the first divided sub-pixel G1 for green) The light shielding film 23 to be referred to is formed, and corresponding color filters 22 (R) and (G) are formed on the upper layer side of the light shielding film 23. That is, a red (R) color filter 22 (R) is formed in the red first divided sub-pixel R1 and the second divided sub-pixel R2, and the first divided sub-pixel G1 and the second divided sub-pixel for green are formed. A green (G) color filter 22 (G) is formed in the pixel G2. Further, a planarizing film 24 made of a photosensitive resin, a translucent common electrode 21 made of an ITO film, and an alignment film 26 are formed on the color filters 22 (R) and (G). Note that a light shielding film 23 called a black matrix may be formed in a region facing each of the vertical and horizontal boundary regions of all the pixel electrodes 9a.

(Detailed configuration of divided sub-pixels)
FIG. 5 is an explanatory diagram showing a planar configuration of each pixel (sub-pixel / divided sub-pixel) in the electro-optical device 100 according to Embodiment 1 of the present invention, and shows four adjacent pixels.

  As shown in FIG. 5, in the electro-optical device 100 of this embodiment, a stripe arrangement is adopted as the color arrangement, and the directions orthogonal to each other are the first direction X (the direction in which the scanning line 3a extends) and the second. When the direction Y is the direction in which the data line 6a extends, the sub-pixel 100b (R) corresponding to red (R) and the sub-pixel 100b (G) corresponding to green (G) are each in the second direction. Is arranged. Therefore, in the pixels 100a arranged along the first direction X, the red sub-pixels 100b (R) and the green sub-pixels 100b (G) are alternately arranged and adjacent in the second direction Y. Between the pixels, the positions of the red sub-pixel 100b (R) and the green sub-pixel 100b (G) in the first direction X coincide with each other. Here, in any of the plurality of pixels 100a, the red sub-pixel 100b (R) and the green sub-pixel 100b (G) have the same size.

  Further, the red sub-pixel 100b (R) is divided into the first divided sub-pixel R1 and the second divided sub-pixel R2 in the first direction X, and the green sub-pixel 100b (G) is divided in the first direction. X is divided into a first divided sub-pixel G1 and a second divided sub-pixel G2.

  Here, each divided sub-pixel (first divided sub-pixel R1 for red, second divided sub-pixel R2 for red, first divided sub-pixel G1 for green, and second divided sub-pixel G2 for green) The size is the same. In addition, the red (R) color filter 22 (R) described with reference to FIG. 4B has the color material density and thickness in the red first divided subpixel R1 and the second divided subpixel R2. Are the same and the darkness is equal. The green (G) color filter 22 (G) described with reference to FIG. 4B has the color material density and thickness in the first divided subpixel G1 and the second divided subpixel G2 for green. Are the same and the darkness is equal.

  Therefore, in this embodiment, the first divided sub-pixel R1 and the second divided sub-pixel R2 have the same luminance characteristics, and the first divided sub-pixel G1 and the second divided sub-pixel G2 have the same luminance characteristics. Here, the luminance characteristics are defined to be equal when the amount of light emitted under the same voltage applied to the pixel electrode 9a is equal.

(Display operation)
6A and 6B are explanatory diagrams showing the relationship between the drive condition for each divided sub-pixel and the light modulation state of the entire pixel in the electro-optical device 100 according to Embodiment 1 of the present invention, and FIG. It is explanatory drawing of the image data which prescribes | regulates the drive condition with respect to a division | segmentation subpixel.

In the electro-optical device 100 according to the present embodiment, since the two-gradation driving method is adopted as the driving method for the divided sub-pixels, as shown in the column (ii) of FIG. 6A, the data is supplied to each data line 6a. The gradation signals to be generated are two voltages corresponding to ON (lit) or OFF (dark). For this reason, each divided sub-pixel (the first divided sub-pixel R1 for red, the second divided sub-pixel R2 for red, the first divided sub-pixel G1 for green, and the second divided sub-pixel G2 for green) Each is independently switched ON (lit) or OFF (dark). As a result, as shown in the column (iii) of FIG. 6A, when the maximum luminance of the entire subpixel is 100%, the luminance in each divided subpixel is switched between 0% and 50%. Accordingly, as shown in the column (iv) of FIG. 6A, the luminance values of the sub-pixels 100b (R = R1 + R2) and 100b (G = G1 + G2) are 0%, 50%, and 100%, respectively. Can be switched to. Here, the luminance in each sub-pixel is 3 levels, but the light modulation state in the pixel 100a partially overlaps. For this reason, as shown in the column (i) of FIG. 6A, in the pixel 100a, the light emitted from the respective divided sub-pixels is synthesized. As a result, the state of the pixel 100a is as follows:
Condition 1: Black
Condition 2: Green50
Condition 3: Green100
Condition 4: Red 50
Condition 5: Yellow50
Condition 6: Yellowish green Condition 7: Red100
Condition 8: Amber
Condition 9: Yellow100
It will be switched to. In addition, the numerical value attached | subjected after each color shows a brightness | luminance (gradation).

  When performing such driving, data Df corresponding to the conditions 1 to 9 for each pixel 100a is input from the upper control unit to the image processing circuit 250 shown in FIG. Based on the data Df and the data set in the lookup table 251, as shown in FIG. 6B, the driving condition in each pixel 100 a is a binary signal of “0” and “1”. The data is converted into image data Ds, and based on the image data Ds, the data line driving circuit 210 outputs a gradation signal to each divided sub-pixel. As a result, each pixel 100a emits light corresponding to each of the conditions 1 to 9 shown in FIG.

(Main effects of this form)
As described above, since the electro-optical device 100 according to the present embodiment employs the two-gradation driving method, the data line driving circuit 210 and the image processing circuit 250 are used to drive the pixel 100a. Simplification of the configuration can be achieved.

  The plurality of sub-pixels 100b (R) and 100b (G) include a plurality of divided sub-pixels (a first divided sub-pixel R1 for red and a second divided sub-pixel for red) that are driven by two gradations independently of each other. As shown in FIG. 6A, since the pixel R2, the first divided subpixel G1 for green, and the second divided subpixel G2 for green are configured with the second gradation subpixel G2. All of the divided sub-pixels can be turned off, some of the divided sub-pixels can be turned off, others can be turned on, and all of the divided sub-pixels can be turned on. For green, red, and yellow, various image displays can be performed, such as halftone display.

  Further, in this embodiment, the pixel 100a is constituted by the sub-pixels 100b (R) and 100b (G) of two colors, and it is assumed that there is no color mixing problem, and only the region facing the boundary region of the divided sub-pixels of different colors. A light shielding film 23 referred to as a black stripe is formed, and the light shielding film 23 is not formed in a region facing the boundary region of the pixel electrode 9a belonging to the divided sub-pixels of the same color. For this reason, the pixel aperture ratio is higher than when three color sub-pixels are used. Therefore, according to this embodiment, an image with high luminance can be displayed.

[Embodiment 2]
FIG. 7 is an explanatory diagram showing a planar configuration of each pixel (subpixel / divided subpixel) in the electro-optical device 100 according to Embodiment 2 of the present invention. 8A and 8B are explanatory diagrams showing the relationship between the drive condition for each divided sub-pixel and the light modulation state in the entire pixel in the electro-optical device 100 according to Embodiment 2 of the present invention, and FIG. It is explanatory drawing of the image data which prescribes | regulates the drive condition with respect to a division | segmentation subpixel. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 7, in the electro-optical device 100 according to the present embodiment, as in the first embodiment, the red sub-pixel 100b (R) and the green sub-pixel 100b are included in any of the plurality of pixels 100a. In any pixel 100a, the red sub-pixel 100b (R) and the green sub-pixel 100b (G) have the same size. Further, the red sub-pixel 100b (R) is divided into the first divided sub-pixel R1 and the second divided sub-pixel R2 in the first direction X, and the green sub-pixel 100b (G) is divided in the first direction. X is divided into a first divided sub-pixel G1 and a second divided sub-pixel G2.

  Here, each divided sub-pixel (first divided sub-pixel R1 for red, second divided sub-pixel R2 for red, first divided sub-pixel G1 for green, and second divided sub-pixel G2 for green) The size is the same.

  However, unlike the first embodiment, in this embodiment, the red (R) color filter 22 (R) described with reference to FIG. 4B includes the red first divided sub-pixel R1 and the second sub-pixel R1. The color material density and thickness are different from each other in the divided sub-pixel R2, and the density is different. In this embodiment, the color filter 22 (R) formed in the first divided subpixel R1 has a lower color material density than the color filter 22 (R) formed in the second divided subpixel R2. Therefore, in the present embodiment, the first divided sub-pixel R1 has a large amount of light emitted under the same voltage applied to the pixel electrode 9a as compared with the second divided sub-pixel R2, and has high luminance characteristics. . In addition, the green (G) color filter 22 (G) described with reference to FIG. 4B has a color material density and thickness in the second divided subpixel G1 and the second divided subpixel G2 for green. Are different and the density is different. In this embodiment, the color filter 22 (G) formed in the first divided sub-pixel G1 has a lower color material density than the color filter 22 (G) formed in the second divided sub-pixel G2. Therefore, in the present embodiment, the first divided sub-pixel G1 has a large amount of light emitted under the same voltage applied to the pixel electrode 9a as compared with the second divided sub-pixel G2, and has high luminance characteristics. .

Also in the electro-optical device 100 of this embodiment, the two-tone drive method is adopted as the drive method for the divided sub-pixels as in the first embodiment. For this reason, as shown in the column (ii) of FIG. 8A, the gradation signals supplied to each data line 6a are two voltages corresponding to ON (lighted) or OFF (lighted off). Accordingly, each divided sub-pixel (the first divided sub-pixel R1 for red, the second divided sub-pixel R2 for red, the first divided sub-pixel G1 for green, and the second divided sub-pixel G2 for green) is respectively Independently, it is switched on (lit) or off (dark). As a result, as shown in the column (iii) of FIG. 8A, when the maximum luminance of the entire subpixel is 100%, the luminance in the first divided subpixels R1 and G1 is 0% and 70%, respectively. Thus, the luminance in the second divided sub-pixels R2 and G2 is switched between 0% and 30%. Therefore, as shown in the column (iv) of FIG. 8A, the luminances at the sub-pixels 100b (R = R1 + R2) and 100b (G = G1 + G2) are 0%, 30%, 70%, and 100%, respectively. Can be switched to. Here, the luminance in each sub-pixel is 4 levels, and there is no overlap in the light modulation state in the pixel 100a. For this reason, as shown in the column (i) of FIG. 8A, in the pixel 100a, the light emitted from the respective divided sub-pixels is synthesized. As a result, the state of one pixel 100a is as follows: 16
Condition 1: Black
Condition 2: Green 30
Condition 3: Green70
Condition 4: Green100
Condition 5: Red 30
Condition 6: Yellow30
Condition 7: Yellowish green 1
Condition 8: Yellowish green 2
Condition 9: Red 70
Condition 10: Amber1
Condition 11: Yellow70
Condition 12: Yellowish green 3
Condition 13: Red100
Condition 14: Amber2
Condition 15: Amber3
Condition 16: Yellow100
It will be switched to. In addition, the numerical value attached | subjected after each color shows a brightness | luminance (gradation).

  Also in this case, as in the first embodiment, the data Df corresponding to the conditions 1 to 9 for each pixel 100a is input to the image processing circuit 250 shown in FIG. In 250, based on the data Df and the data set in the lookup table 251, the driving condition in each pixel 100a is binarized as “0” and “1” as shown in FIG. 8B. The signal is converted into image data Ds composed of signals, and based on the image data Ds, the data line driving circuit 210 outputs a gradation signal to each divided sub-pixel. As a result, each pixel 100a emits light corresponding to each of the conditions 1 to 9 shown in FIG.

  As described above, since the electro-optical device 100 according to the present embodiment also uses the two-gradation driving method as in the first embodiment, the configuration of the data line driving circuit 210 and the image processing circuit 250 is simple for driving the pixel 100a. Can be achieved.

  The plurality of sub-pixels 100b (R) and 100b (G) include a plurality of divided sub-pixels (a first divided sub-pixel R1 for red and a second divided sub-pixel for red) that are driven by two gradations independently of each other. Since the pixel R2, the first divided sub-pixel G1 for green, and the second divided sub-pixel G2 for green), all of the divided sub-pixels are turned off and divided even in the case of two-tone driving. Some of the sub-pixels can be turned off, others can be turned on, and all of the divided sub-pixels can be turned on. Therefore, even with the two-tone drive method, various image displays such as halftone display are possible for green, red, yellow, yellow-green, and amber.

  Further, in this embodiment, the pixel 100a is constituted by the sub-pixels 100b (R) and 100b (G) of two colors, and it is assumed that there is no color mixing problem, and only the region facing the boundary region of the divided sub-pixels of different colors. The light shielding film 23 is formed in the region, and the light shielding film 23 is not formed in the region facing the boundary region of the pixel electrode 9a belonging to the divided sub-pixel of the same color. For this reason, since the pixel aperture ratio is higher than when three color sub-pixels are used, an image with high luminance can be displayed.

  Furthermore, in this embodiment, it is possible to realize a three-tone color for mixed colors such as yellowish green and amber. Therefore, it is possible to respond to the taste of the user, such as being able to select a favorite color according to the use environment.

[Modification of Embodiment 2]
FIG. 9 is an explanatory diagram illustrating a planar configuration of each pixel (subpixel / divided subpixel) in the electro-optical device 100 according to the modification of the second embodiment of the present invention. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  In the second embodiment, the darkness of the color filters 22 (R) and 22 (G) is set between the first divided subpixel R1 and the second divided subpixel R2 for red, and the first divided subpixel for green. The luminance characteristics of the first divided sub-pixels R1 and G1 are set higher than those of the second divided sub-pixels R2 and G2 by making the difference between G1 and the second divided sub-pixel G2, but as shown in FIG. Further, the color material density and thickness of the color filters 22 (R) and 22 (G) are set between the first divided sub-pixel R1 and the second divided sub-pixel R2 for red, and the first divided sub-pixel for green. G1 is the same between the second divided subpixel G2, and the size of the divided subpixel is between the first divided subpixel R1 and the second divided subpixel R2 for red, and the first divided subpixel for green The first divided sub-pixel R1 is differentiated between G1 and the second divided sub-pixel G2. Luminance characteristics of G1 may be set higher than the second divided sub-pixels R2, G2. In this embodiment, the size ratio between the first divided subpixel R1 and the second divided subpixel R2 is 7: 3, and the size ratio between the first divided subpixel G1 and the second divided subpixel G2 is 7: 3. is there. Other configurations are the same as those in the second embodiment, and thus description thereof is omitted.

  Even when such a configuration is adopted, as described with reference to FIGS. 8A and 8B in the second embodiment, the luminance in each sub-pixel is 0%, 30%, 70%, 100, respectively. Since the pixel 100a can be driven under a total of 16 conditions, the same effects as in the second embodiment can be obtained.

  In this embodiment, the color material concentrations and thicknesses of the color filters 22 (R) and 22 (G) are set between the first divided sub-pixel R1 for red and the second divided sub-pixel R2 and for the green color. Since it is the same between the first divided sub-pixel G1 and the second divided sub-pixel G2, one color filter can be formed in the same process using the same material. Therefore, according to this embodiment, there is an advantage that production efficiency can be improved.

[Other embodiments]
In the first and second embodiments, the sub-pixel 100b (R) corresponding to red (R) and the sub-pixel 100b (G) corresponding to green (G) are alternately arranged in the first direction X, and the sub-pixel 100b. (R) and 100b (G) are divided into the first divided sub-pixels R1 and G1 and the second divided sub-pixels R2 and G2 in the first direction X. As shown in FIG. A configuration in which the sub-pixels 100b (R) and 100b (G) are divided into the first divided sub-pixels R1 and G1 and the second divided sub-pixels R2 and G2 in the second direction Y may be adopted. Also, as shown in FIG. 10 (b), sub-pixels 100b (R) corresponding to red (R) and sub-pixels 100b (G) corresponding to green (G) are alternately arranged in the second direction Y, A configuration in which the sub-pixels 100b (R) and 100b (G) are divided into the first divided sub-pixels R1 and G1 and the second divided sub-pixels R2 and G2 in the first direction X may be adopted.

  In the first and second embodiments, the red sub-pixel 100b (R) and the green sub-pixel 100b (G) are provided in one pixel 100a, but the colors corresponding to the sub-pixels are red and green. The combination of red and blue may be adopted. Regarding colors corresponding to the sub-pixels, one sub-pixel may be associated with a color such as red, green, and blue, and the other sub-pixel may be associated with white. This can be realized by omitting the formation of the filter.

  In the first and second embodiments, two subpixels corresponding to different colors are provided in one pixel 100a. However, three or more subpixels, for example, subpixels corresponding to red, green, and blue are provided. May be.

  In the first and second embodiments, two divided subpixels are provided in the subpixel, but three or more divided subpixels may be provided.

  In the first and second embodiments, the divided subpixels are provided in all of the plurality of subpixels provided in one pixel 100a. However, the divided subpixels are provided only in at least some of the subpixels. May be.

  In the first and second embodiments, the stripe arrangement is employed as the color arrangement. However, between the pixels adjacent in the second direction Y, the sub-pixel 100b (R) and the sub-pixel 100b (G) You may employ | adopt the delta arrangement | sequence from which the position in the 1st direction X has shifted | deviated only by the dimension corresponded to 1/2 time of a pitch. If such a configuration is adopted, when the electro-optical device 100 is provided with a cover, the end at the arrow X is covered with the cover, and a line of a specific color is displayed when a line is displayed at the end. This can be prevented.

  In the first and second embodiments, the polysilicon film is used as the semiconductor film. However, the present invention may be applied to the element substrate 10 using an amorphous silicon film or a single crystal silicon layer. Further, the present invention may be applied to a liquid crystal device using a thin film diode element (nonlinear element) as a pixel switching element.

  In the above embodiment, the present invention is applied to a TN (Twisted Nematic) type liquid crystal device (electro-optical device). The present invention may be applied to a liquid crystal device (electro-optical device) of a type in which liquid crystal is driven by a horizontal electric field, such as a switching) method.

  Furthermore, although the liquid crystal device has been described as an example of the electro-optical device in the above embodiment, the present invention may be applied to an electro-optical device using an electro-optical material other than liquid crystal, for example, an organic electroluminescence device.

[Example of mounting on electronic equipment]
Next, an electronic apparatus to which the electro-optical device 100 according to the above-described embodiment is applied will be described. FIG. 11A shows a configuration of a mobile phone provided with the electro-optical device 100. A cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and the electro-optical device 100 as a display unit. By operating the scroll button 3002, the screen displayed on the electro-optical device 100 is scrolled. FIG. 11B shows a configuration of a portable information terminal (PDA: Personal Digital Assistants) to which the electro-optical device 100 is applied. The information portable terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and the electro-optical device 100 as a display unit. When the power switch 4002 is operated, various types of information such as an address book and a schedule book are displayed on the electro-optical device 100.

  Note that examples of the electronic apparatus to which the electro-optical device 100 is applied include a pager, an electronic notebook, a calculator, a POS terminal, a device including a touch panel, and the like in addition to those illustrated in FIG. The electro-optical device 100 described above can be applied as a display unit of these various electronic devices.

It is explanatory drawing which shows typically the basic composition of the head-up display as an example of the electronic device by which the electro-optical apparatus to which this invention is applied is mounted. 1 is a block diagram illustrating an electrical configuration of an electro-optical device to which the present invention is applied. (A), (b) is the top view which looked at the electro-optical apparatus to which this invention was applied from the opposing board | substrate side with each component, respectively, and its HH 'sectional drawing. FIGS. 4A and 4B are plan views of adjacent pixels on the element substrate used in the electro-optical device to which the present invention is applied, and the electro-optical device cut at a position corresponding to the line AA ′. FIG. FIG. 3 is an explanatory diagram illustrating a planar configuration of each pixel (sub pixel / divided sub pixel) in the electro-optical device according to the first embodiment of the invention. (A), (b) is explanatory drawing which shows the relationship between the drive condition with respect to each division | segmentation subpixel in the electro-optical apparatus which concerns on Embodiment 1 of this invention, and the light modulation state in the whole pixel, and each division | segmentation subpixel It is explanatory drawing of the image data which prescribes | regulates the drive condition with respect to. FIG. 6 is an explanatory diagram illustrating a planar configuration of each pixel (sub pixel / divided sub pixel) in the electro-optical device according to the second embodiment of the invention. (A), (b) is explanatory drawing which shows the relationship between the drive condition with respect to each division | segmentation subpixel in the electro-optical apparatus which concerns on Embodiment 2 of this invention, and the light modulation state in the whole pixel, and each division | segmentation subpixel It is explanatory drawing of the image data which prescribes | regulates the drive condition with respect to. FIG. 10 is an explanatory diagram illustrating a planar configuration of each pixel (sub pixel / divided sub pixel) in an electro-optical device according to a modification of the second embodiment of the present invention. (A), (b) is explanatory drawing which respectively shows the planar structure of each pixel (subpixel / divided subpixel) in the electro-optical apparatus which concerns on other embodiment of this invention. It is explanatory drawing of the electronic device using the electro-optical apparatus which concerns on this invention.

Explanation of symbols

9a ··· Pixel electrode, 10 · · Element substrate, 10b · · Pixel array region, 20 · · Opposite substrate, 22 (R), (G) · · Color filter, 30 · · Thin film transistor, 100 · · Electro-optical device, 100a..Pixels, 100b (R), (G) .. Subpixels, 110..Backlight device (light source), 120..Mirror (optical system), 210..Data line driving circuit, 220..Scanning line Drive circuit, 250... Image processing circuit, 1000... Head-up display (electronic device), R1... Red first divided subpixel, R2... Red second divided subpixel, G1. First divided sub-pixel, second divided sub-pixel for G2,... Green

Claims (13)

In an electro-optical device including a plurality of pixels,
Each of the plurality of pixels includes a plurality of sub-pixels that emit light of different colors,
Among the plurality of sub-pixels, at least one sub-pixel includes a plurality of divided sub-pixels that emit light of the same color, and each of the plurality of divided sub-pixels is independently driven with two gradations. An electro-optical device.   The electro-optical device according to claim 1, wherein each of the plurality of sub-pixels emits different colored light.   The electro-optical device according to claim 1, wherein one pixel includes two sub-pixels.   4. The electro-optical device according to claim 1, wherein each of the plurality of sub-pixels includes the plurality of divided sub-pixels. 5.   5. The electro-optical device according to claim 1, wherein one of the sub-pixels includes two divided sub-pixels.   The electro-optical device according to claim 1, wherein the plurality of divided sub-pixels have the same luminance characteristic in the sub-pixel.   6. The electro-optical device according to claim 1, wherein the plurality of divided sub-pixels have different luminance characteristics in the sub-pixel.   The electro-optical device according to claim 7, wherein the plurality of divided sub-pixels include color filters having different densities in the sub-pixel.   The electro-optical device according to claim 7, wherein the plurality of divided sub-pixels have different light emission areas in the sub-pixel.   An element substrate on which pixel electrodes corresponding to the sub-pixels are formed; a counter substrate disposed opposite to the element substrate; and a liquid crystal held between the element substrate and the counter substrate. The electro-optical device according to claim 1, wherein the electro-optical device is characterized in that:   An electronic apparatus comprising the electro-optical device according to claim 1.   A light source for supplying light to the electro-optical device; and an optical system for projecting display light obtained by optically modulating light emitted from the light source toward the projection surface. The electronic device according to claim 11. In a driving method of an electro-optical device including a plurality of pixels,
Each of the plurality of pixels is provided with a plurality of sub-pixels that emit light of different colors, and at least one sub-pixel of the plurality of sub-pixels has a plurality of divisions that emit light of the same color Providing sub-pixels,
A driving method of an electro-optical device, wherein each of the plurality of divided sub-pixels is driven independently with two gradations.

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