JP2005352474A - Color display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color display device capable of improving light utilization efficiency and capable of multicolor display.
SOLUTION: A plurality of pixels 20 of a color display element using a medium having a lightness change range in which the lightness is changed by the modulation means and a hue change range in which the hue is changed by the modulation means are used in a modulation region based on the hue change. The first sub-pixels 24 to 26 that perform color display and the second sub-pixels 21 to 23 that are provided with color filter layers of at least two different colors of red, green, and blue.
[Selection] Figure 1

Description

  The present invention relates to a color display device.

  Currently, flat panel displays, which are examples of color display devices, are widely used for various monitors such as personal computers and mobile phones, and will continue to become increasingly popular in the future, such as the development of large-screen TVs. It is predicted. Among them, the most widespread is a liquid crystal display device, and a color display method called a micro color filter method is widely used as a color display method in such a liquid crystal display device.

  Here, in this micro color filter system, one pixel is divided into at least three sub-pixels, and three primary color red (R), green (G), and blue (B) color filters are provided for each. Provides a full color display, and has an advantage that high color reproduction performance can be easily realized.

  However, on the other hand, since the transmittance becomes 1/3, there is a disadvantage that the light utilization efficiency is deteriorated. Such poor light utilization efficiency is a cause of increased power consumption of the backlight and the front light in a transmissive liquid crystal display device having a backlight and a reflective liquid crystal display device having a front light. ing.

  Recently, as a liquid crystal display element used in a liquid crystal display device, there is a transflective liquid crystal display element in which a part of a region is a light reflective region and a part of a region is a light transmissive region ( For example, refer nonpatent literature 1). Such a transflective liquid crystal display element has been widely used in mobile phones, portable information terminals and the like. In particular, portable electronic devices are often used outdoors, and are required to ensure sufficient visibility even in very bright outside light, and to ensure high contrast and color reproducibility even in dark rooms. Is done.

  In recent years, several display elements having better visibility than liquid crystal display elements have been reported as electronic paper displays. Many of them try to realize a bright display by not using a polarizing plate. However, even in these display elements, although a bright display is realized in monochrome, color display can only be performed using a color filter in the same manner as a liquid crystal display element, and color display is realized with brightness comparable to paper. The situation is not yet complete.

  On the other hand, as a color display device capable of performing color display without using a color filter, one using an ECB type (electric field control birefringence effect type) liquid crystal display element is known. Here, the ECB type liquid crystal display element includes a transmissive type and a reflective type in which a liquid crystal cell having a liquid crystal sandwiched between a pair of substrates is sandwiched and polarizing plates are disposed on the front side and the back side, respectively. In addition, this reflective type has a single polarizing plate type in which a polarizing plate is disposed only on one substrate, and a polarizing plate is disposed on both substrates, and a reflecting plate is provided outside the polarizing plate. There is a sheet polarizing plate type.

  Here, in the case of a transmissive ECB liquid crystal display element, linearly polarized light that has been transmitted through one polarizing plate enters the liquid crystal cell, and each wavelength light is polarized by the birefringence action of the liquid crystal layer. The light that has become the elliptically polarized light of which the light is incident on the other polarizing plate, and the light that has passed through the other polarizing plate is a color corresponding to the ratio of the light intensity of each wavelength light constituting the light Become colored light.

  Thus, the ECB type liquid crystal display element colors light by utilizing the birefringence action of the liquid crystal and the polarization action of the polarizing plate, and does not absorb the light by the color filter. Can be increased to obtain a bright color display. In addition, since the birefringence of the liquid crystal layer changes according to the voltage, the color of transmitted light and reflected light can be changed by controlling the voltage applied to the liquid crystal cell. It can also be displayed.

  FIG. 10 shows the relationship between the birefringence amount (referred to as retardation R) of such an ECB type liquid crystal display element and the coordinates on the chromaticity diagram. From FIG. Although it is almost achromatic in the center of the chromaticity diagram, it can be seen that the color changes according to the amount of birefringence when it is higher.

  In this case, a material having a negative dielectric anisotropy (expressed as Δε) is used as the liquid crystal. When such a liquid crystal is aligned vertically with respect to the substrate when no voltage is applied, the liquid crystal molecules As the liquid crystal tilts, the birefringence of the liquid crystal increases.

  At this time, under crossed Nicols, the chromaticity changes along the curve of FIG. That is, when no voltage is applied, R is almost 0, so light is not transmitted and is in a dark state (black state). However, as the voltage increases, the brightness increases from black to gray to white. . When the voltage is further increased, the color changes, and the color changes, such as yellow → red → purple → blue → yellow → purple → light blue → green.

  Thus, the ECB type liquid crystal display element can change the brightness between the maximum brightness and the minimum brightness by the voltage in the modulation region on the low voltage side, and can change a plurality of hues by the voltage in the higher voltage region. Can do.

  By the way, as shown in FIG. 10, the color obtained by retardation is considerably lower in purity than the maximum purity color at the outer edge on the chromaticity diagram. As a method for compensating for this, there is a method using a color filter in combination. That is, the purity of the ECB display color can be increased by passing the same color filter. For example, in order to obtain a high-purity red color, a red or yellow color filter is disposed on a pixel that does not perform blue display, and the red short wavelength component obtained by the ECB effect is cut, so that a high-purity red color is obtained. (For example, refer to Patent Document 1).

  In the following, the retardation range (0 to 250 nm) in which the brightness changes from black to gray to white on the chromaticity diagram is referred to as the brightness change range, and the chromatic color change range above yellow (250 nm or more) is referred to as the hue change range. . In addition, since the boundary between the achromatic color and the chromatic color cannot be clearly determined, 250 nm in the above range is a rough standard.

  Hereinafter, a color obtained by retardation will be referred to, which is a color along the curve of FIG. As shown in FIG. 10, the point where the purity becomes maximum has retardations near 450 nm, 600 nm, and 1300 nm, and is visually recognized as red, blue, and green. However, since there is a range that can be regarded as substantially the same color with a width of about 100 nm before and after these points, the colors in the range are also referred to as red, blue, and green. Magenta is in the middle of 530 nm between red and blue.

  Furthermore, colors of color filters used in liquid crystal display devices and the like are usually more pure than colors obtained by retardation, and are outside the above range on the chromaticity diagram. To.

Sharp Technical Report No. 83, August 2002 p. 22 JP-A-4-052625

  By the way, although the liquid crystal display device (color display device) using the conventional ECB type liquid crystal display element can perform color display, since this color display is a display based on a hue change utilizing the birefringence effect, it is applied. Although it is possible to control the hue by the amount of voltage, it has been difficult to display a smooth gradation color in that hue.

  Therefore, the color display can be displayed only with a limited number of colors. Note that the tone color is not mentioned in Patent Document 1 described above.

  Accordingly, the present invention has been made in view of such a current situation, and an object of the present invention is to provide a color display device capable of improving multi-color display while improving light utilization efficiency.

  The present invention uses a medium having a lightness change range in which the lightness is changed by the modulation means and a hue change range in which the hue is changed by the modulation means, and a color display device including a color display element having a plurality of pixels. The pixel of the color display element is provided with a first subpixel that performs color display using the modulation region based on the hue change, and a color filter layer of at least two different colors of red, green, and blue. It is characterized by comprising two sub-pixels.

  As in the present invention, a plurality of pixels of a color display element are provided with a first sub-pixel that performs color display using a modulation region based on a hue change, and color filter layers of at least two different colors of red, green, and blue By using the second subpixels arranged, the light utilization efficiency is improved and multicolor display is possible.

  FIG. 1 is a diagram showing the structure of one pixel of a color display element used in a color display device according to the best mode for carrying out the present invention. Next, the principle of color display operation of this color display element will be described. Note that various types of color display elements can be applied to the color display element according to the present invention. The display principle will be described by taking a liquid crystal display element using a liquid crystal having an ECB effect as an example.

  In the liquid crystal display element (color display element) according to the present embodiment, as shown in FIG. 1, one pixel 20 is divided into a plurality (six) subpixels 21 to 26 and each subpixel 21 to 26 is divided. In addition, color filters of red (R), green (G), blue (B), cyan (C), magenta (M), and yellow (Y) are arranged.

  Here, in all of these sub-pixels 21 to 26, by adjusting the retardation of the liquid crystal layer, it is possible to use an achromatic brightness change from black to white. For example, when the white color is displayed, the colors of the color filters indicated by the symbols R, G, B, C, M, and Y are displayed. Therefore, if all the liquid crystal layers are displayed in white, the subpixels 21 to 23 have RGB colors. White display is performed by additive color mixture, and the sub-pixels 24 to 26 are white display by additive color mixture of YMC. As a result, white display is obtained for the entire pixel.

  In general, white display using only RGB additive color mixing reduces the light utilization efficiency by one-third compared to white display using no color filter, but white display using YMC additive color mixing is white by RGB additive color mixing. The light utilization efficiency can be doubled for display. Therefore, in the case of this configuration, it is possible to obtain a light use efficiency 1.5 times that of white display by RGB additive color mixture as a whole.

  Here, the method of performing color display using such a color filter is the same as the normal micro color filter method, but in the liquid crystal display element according to the present embodiment, the retardation of the liquid crystal layer is changed, Displays chromatic colors.

  For example, in the sub-pixel 25 in which the magenta color filter is disposed, in the region where the retardation is small, the color is changed from black to white as described above. In this case, the color of the color filter is observed, so that the color changes from black to dark magenta. All magenta continuous tone display is possible. Further, since an interference color based on the ECB effect is displayed in a region where retardation is large, any color ranging from red to magenta to blue can be displayed. Since the magenta color filter can display all of red, magenta, and blue, the display of red, magenta, and blue is observed even after passing through the magenta color filter.

  On the other hand, when displaying a high-purity red color based on the principle of the conventional micro color filter method, the sub-pixel 21 must be lit, whereas in the liquid crystal display element of the present embodiment, the sub-pixel 25 is used in combination with a red display utilizing the ECB effect, a bright and highly pure red display can be performed.

  Further, by the same discussion, the sub-pixel 24 can be displayed in red, yellow, and green by using the ECB effect. That is, it is possible to display a brighter red color by combining the red display in the sub-pixel 24 provided with the yellow color filter.

  Note that bright primary colors can be displayed for green and blue based on the same principle. That is, according to the present embodiment, it is possible to achieve both a white display that is approximately 1.5 times brighter than the conventional micro color filter system and a bright three primary color display.

  Next, displayable colors using such a display principle will be specifically described.

  In this embodiment, first subpixels (groups) 24 to 26 that display chromatic colors by changing the retardation of the liquid crystal layer by applying voltage by a modulation unit that can control a power source (not shown), and color filters are provided. The unit pixel is composed of second subpixels (groups) 21 to 23 that display the color of the color filter by changing the retardation in the brightness change range according to the voltage. The first subpixel (group) 24-26 is provided with a YMC color filter having a complementary color relationship with RGB, and the second subpixel (group) 21-23 is provided with an RGB color filter. ing.

  Here, displayable colors will be described using the RGB color solid shown in FIG. As shown in FIG. 2, each side of the RGB color solid corresponds to an independent vector composed of an R axis, a G axis, and a B axis. Here, in the RGB micro color filter method, it is possible to express all points in the RGB color solid by dividing one pixel into three subpixels and individually controlling the sizes of these independent vectors. It has become.

  On the other hand, the liquid crystal display element of the present embodiment uses a YMC color filter in addition to the RGB color filter generally used for the existing liquid crystal display element. In this case, the basic vector in the RGB color solid when the YMC color filter is used is as shown in FIG. 3, and the displayable area is inside the hexahedron consisting of the basic vector of YMC in FIG.

  Therefore, when the RGBYMC color filter is used as a liquid crystal display element using a micro color filter method using only a monochrome modulation area as in the prior art, the displayable point is the vector in FIG. 3 from any point in FIG. It can be said that an arbitrary point (not shown) is added. According to this, since the primary color axis has the maximum display color obtained by the RGB color filter, it can be understood that a bright primary color display with high color purity cannot be obtained as described above.

  On the other hand, as described above, the liquid crystal display element of the present invention is characterized in that primary color display can be performed even in a complementary color filter subpixel by using a coloring phenomenon based on the ECB effect. If this is expressed on the color solid, for example, in the yellow (Y) sub-pixel, not only the yellow continuous tone but also red and green can be displayed. And point Ry and point Gy. As a result, in the present liquid crystal display element, as shown in FIG. 5, it is possible to express an area where the RGB cube starting from these points Ry and Gy is defined.

  By repeating the same discussion, it is possible to fill in an arbitrary point in the color solid. This point will be described in detail below.

  Now, assuming that the maximum luminance of white display obtained by the present liquid crystal display element is 1, this brightness of 1 is obtained by the sum of cyan blue component, magenta blue component, and blue color filter in the blue wavelength range, for example. It is done. The same idea can be applied to green and red.

  That is, the color solid obtained by the RGB color filter pixels represents a solid whose length of one side is 1/3 of the maximum luminance and each side can take a continuous value. The coordinates on the color solid that can be realized by the RGB color filter pixels will be described.

  Next, consider the YMC color filter.

  As described above, yellow (Y) subpixels can display yellow, red, and green. It can be seen that the brightness displayed here becomes 1/3 by the same discussion. Therefore, for the display colors obtained in the yellow (Y) sub-pixel, the obtained brightness is expressed in terms of yellow (1/3, 1/3, 0), green (0, 0) using the (R, G, B) coordinates. 1/3, 0) and red (1/3, 0, 0). For yellow, any value from 0 to 1/3 can be taken, but only the maximum value is considered here for simplicity.

  Similarly, magenta (1/3, 0, 1/3), blue (1/3, 0, 0), red (1/3, 0, 0) are obtained for magenta (M) subpixels, and cyan ( C) Cyan (1/3, 1/3, 0), blue (1/3, 0, 0), green (0, 1/3, 0) are obtained in the sub-pixel. In addition, a plurality of additively mixed display colors can be obtained by simultaneously lighting a plurality of pixels of YMC.

  As described above, any point in a cube whose one side is 1/3 can be expressed by the RGB color filter pixels. Accordingly, in the cube having the origins (0, 0, 0) and (2/3, 2/3, 2/3) as vertices, lattice points having 1/3 intervals as shown in FIG. 6 are YMC color filter pixels. If all can be expressed by the above, it is possible to fill all of the color solids with one side by additive color mixing.

  Accordingly, Tables 2 and 3 show examples of combinations for obtaining the lattice points using the YMC color filter.

  By using the combination as described above and appropriately adjusting the display color of the YMC color filter, it is possible to realize all the lattice points. The above is only an example. For example, in order to realize (1/3, 0, 1/3), in addition to a method of displaying magenta with a magenta (M) subpixel, a yellow (Y) subpixel is displayed. Since a method of displaying blue with red and cyan (C) subpixels is also conceivable, an optimal combination may be selected as appropriate according to the situation.

  In the above example, the display color by the YMC pixel has been described using a point on the grid point without using the gradation color, but a halftone of the YMC pixel may be used depending on the situation.

  With the combinations described above, any point in the color solid can be expressed completely, so that full color can be realized.

  Further, for example, when the display color in the yellow color filter is to be displayed in red in the yellow (Y) subpixel, the retardation amount of the liquid crystal layer is a similar color that allows red display without using the color filter. Although it is possible by controlling the voltage, the drive voltage may be controlled to display colors having different system colors, for example, displaying a magenta color as a liquid crystal layer. In this case, red can be obtained by subtractive color mixture of the display color of the liquid crystal layer and the yellow color filter.

  By the way, when taking the said structure, it is necessary to form a color filter of 6 colors on a board | substrate, and a process becomes difficult. Therefore, by adopting the following configuration, it is possible to obtain a bright multicolor display.

(1) Configuration to omit any or all of complementary color filters (2) Configuration using four RCGM color filters (3) Configuration to stack YMC color filters

  Here, in the case of the configuration (1), the YMC color filter pixels can be displayed in full color without using intermediate colors, that is, it is not necessary to display a complementary halftone, so these complementary color filters are not provided. A similar display color can be obtained only by a coloring phenomenon based on the ECB effect. This makes it possible to realize full color display while reducing the color filter process load. Any one or two of YMC may be used. This also reduces the load on the color filter process, and it is possible to realize full color display with high color purity by the effect of the color filter.

  The configuration (2) is a method of dividing one pixel into four sub-pixels, and the concept of display colors that can be taken in a color solid can be considered in the same manner as described above. According to this configuration, since the B and Y color filters are omitted, blue continuous tone display and display using the above-described yellow pixels cannot be performed, and thus full color display is impossible. However, since the visual sensitivity characteristic of the human eye is insensitive to blue, even with such a configuration, natural display can be performed by performing image processing such as dithering. This is particularly effective for high-definition display elements. This allows the color filter process to be completed four times.

  The configuration (3) will be described with reference to FIG. One primary color can be obtained by stacking two complementary colors and subtractively mixing them. FIG. 7 shows a laminated structure of YMC for obtaining RGB. If this is utilized, six color filters can be realized with only three kinds of color filter materials. At this time, by adopting the configuration as shown in FIG. 8 and forming the color filters in the order of Y → M → C, the process can be performed three times as in the conventional case, and the cost is not increased. Of course, the color filters of the four sub-pixels (2) may be formed based on this concept.

  As described above, the liquid crystal display element according to this embodiment can realize bright white display and bright primary color display at low cost. As a result, an element with higher light utilization efficiency can be obtained as compared with the conventional method of displaying the three primary colors using only the RGB color filter. Therefore, the present liquid crystal display element can be used as a reflective liquid crystal display element in a paper-like display or electronic paper.

  On the other hand, the liquid crystal display element of this configuration has a high transmittance of the liquid crystal layer, so that less backlight power is required to obtain the same brightness as that of the conventional method, and transmission is possible from the viewpoint of lower power consumption. It is also suitably used as a liquid crystal display element.

  Furthermore, since there is high-speed response using liquid crystal, this liquid crystal display element can also be used for moving image display. Conventionally, for a liquid crystal display element for television use, a driving method called “pseudo-impulse driving” in which a backlight extinguishing period is provided within one frame period in order to realize clear moving image characteristics is disclosed in JP-A-2001-272958. However, the problem is that the luminance is reduced by the amount of time for which the extinguishing period is provided. However, the above problem can be solved for such applications by applying a liquid crystal display element having a high response speed and a high transmittance as in the present liquid crystal display element. Further, it is also suitably used for a projection display element that requires high light utilization efficiency.

  Next, a method for using the coloring phenomenon due to the ECB effect even for retardation values other than primary colors will be described.

  For example, FIG. 5 illustrates an example in which green and red are displayed in the yellow sub-pixel by the coloring phenomenon due to the ECB effect. However, in the coloring phenomenon due to the ECB effect, as shown in FIG. The color tone can be changed. That is, there are many chromatic colors that can be used in addition to the primary color display described in the above description. By using such display colors, it is possible to increase the variation of the full color display in the above description.

  By the method described above, it is possible to display a very large number of colors corresponding to full color (multicolor display) while maintaining high light utilization efficiency.

  In addition to the VA mode in which the liquid crystal molecules of the liquid crystal layer are aligned substantially perpendicular to the substrate surface when no voltage is applied, and the retardation is changed by tilting from the substantially vertical alignment when a voltage is applied, the following various liquid crystals are described. Applicable to display mode.

  In the OCB (Optically Compensated Bend) mode, the liquid crystal molecules in the liquid crystal layer change the retardation by changing the alignment state between the bend alignment and the substantially vertical alignment by applying a voltage, and therefore the present invention can be applied to the VA mode. It is the same.

  In the present invention, in order to use the display color due to the retardation change, it is necessary to consider the color tone change due to the viewing angle. However, recent progress in LCD development is remarkable, and it is no exaggeration to say that the problem of viewing angle dependency is almost solved in color liquid crystal displays using the RGB color filter system. For example, in the OCB mode, it is reported that the retardation change accompanying the change in the viewing angle is suppressed by the self-compensation effect by the bend alignment.

  In addition, the viewing angle characteristics of the STN mode are greatly improved due to the development of the retardation film. Since the OCB and STN modes can obtain a coloring phenomenon based on the ECB effect by appropriately setting the retardation amount, the configuration of the present invention can be applied. In particular, in the OCB mode, the response speed described above can be greatly improved. Therefore, the OCB mode is preferably used in applications that require high speed.

  On the other hand, the MVA (Multidomain Virtual Alignment) mode has already been commercialized and widely used as a mode exhibiting very good viewing angle characteristics. In addition, a mode called a PVA (Patterned Virtual Alignment) mode is also widely used.

  In these vertical alignment modes, the surface is uneven (MVA), the electrode shape is devised (PVA), and the liquid crystal molecule tilt direction during voltage application is tilted in at least two director directions with different optical axes. By controlling to, wide viewing angle characteristics are realized. Since these are modes in which the amount of retardation is changed by voltage, the configuration of the present invention can be applied. By doing so, it is possible to realize a liquid crystal display element that simultaneously satisfies high transmittance (or reflectance), a wide viewing angle, and a wide color space.

  In addition, a CPA (Continuous Pinwheel Alignment) mode has been proposed as an alignment mode that takes a vertical alignment state when no voltage is applied, similar to the above. (See Sharp Technical Report: No. 80, August 2001, p. 11)

  Similar to the PVA method, this mode is a method of controlling the tilt direction of the liquid crystal molecules during voltage application by devising the electrode shape. In this method, when a voltage is applied, a wide viewing angle is realized by an alignment state in which liquid crystal molecules are inclined radially from the center of the subpixel. Since this CPA mode is also a mode in which the retardation amount is changed by the voltage, the configuration of the present invention can be applied.

  Note that, in the CPA mode, by using the reverse TN method using a liquid crystal material to which a chiral material is added in order to increase the transmittance of the liquid crystal, the birefringence and the optical rotation can be used together. It becomes high (refer to the above-mentioned document). This addition of chiral material can also be applied in the configuration of the present invention.

  However, in the configuration of the present invention, when a reflective liquid crystal is used and a circularly polarizing plate is used, it is possible to obtain a good reflectance without adding a chiral material in the CPA mode. This will be described below.

  Considering a configuration in which three layers of a circularly polarizing plate, a liquid crystal layer, and a reflector are laminated, first, when the liquid crystal layer has no birefringence, for example, when the liquid crystal layer is in a vertically aligned state, it is from the outside. The incident light first passes through the circularly polarizing plate and is reflected without being modulated in the polarization state, and the reflected light passes through the circularly polarizing plate again and proceeds toward the outside. Here, since the light passes through the circularly polarizing plate twice, the light does not come out to the outside especially in the wavelength region satisfying the circular polarization condition. In other words, the CPA mode that is vertically aligned in the state where no voltage is applied is a normally black configuration in the above configuration.

  Here, when a voltage is applied, the liquid crystal molecules tilt radially, and therefore tilt in all directions with respect to the azimuth angle direction. When the linearly polarized light is incident on the liquid crystal layer as in the above document, the light use efficiency is reduced when the molecular axis direction of the liquid crystal coincides with the polarization direction of the polarizing plate. In the case where the circularly polarized light is incident on the layer, the polarized light is modulated equally regardless of the molecular axis direction in which the liquid crystal is tilted.

  Based on the above principle, when the CPA mode is applied in the reflective display mode using the circularly polarizing plate in the configuration of the present invention, a chiral material may be added as described in the above-mentioned document, It is not necessary to add a chiral material.

  By the way, as explained in the above prior art, the cross-sectional configuration used in the transflective liquid crystal display element has a cell thickness of the transmissive part in order to maximize the light use efficiency of both the transmissive part and the reflective part. An interlayer insulating film is provided so as to be twice the cell thickness of the reflection portion, which is publicly known. The above-described known configuration can be employed also in the present liquid crystal display element.

  On the other hand, in the present liquid crystal display element, when the above configuration is to be realized, the liquid crystal display does not use a twisted nematic (TN) type liquid crystal element or the like because it is based on a display principle using coloring by birefringence. A cell thickness thicker than the device is required. That is, a configuration is required in which the thickness of the interlayer insulating film is larger than that of a normal transflective liquid crystal display element.

  Therefore, the display mode described above is used for the reflection mode portion, and RGB color filters are used for the transmission mode portion, and the liquid crystal layer is a commonly used micro color that continuously changes the transmittance from black to white. A filter system is adopted. In other words, it is possible to realize a transflective liquid crystal with high light utilization efficiency by using the reflection mode as a full color mode using coloring by the ECB effect and the transmission mode as a color display using color filters for all of red, green and blue. . Since the present liquid crystal display element originally has a color filter that transmits RGB primary colors, even if such a configuration is adopted as a transflective type, it does not lead to a significant increase in cost.

  Note that any of a direct drive method, a simple matrix method, and an active matrix method can be used for driving the liquid crystal display element of this embodiment. The substrate used may be glass or plastic. In the case of the transmissive type, both of the pair of substrates need to be light transmissive, but in the case of the reflective type, a substrate that does not transmit light may be used as the support substrate of the reflective layer. Further, a flexible substrate may be used as the substrate to be used.

  In the case of a reflective type, a so-called forward scattering plate method in which a specular reflection plate is used as a reflection plate and a scattering plate is provided outside the liquid crystal layer, or a so-called directivity is provided by devising the shape of the reflection surface. Various reflectors such as a directional reflector can be used. In this embodiment, the vertical alignment mode is exemplified as an example. However, other modes such as a parallel alignment mode, a HAN type mode, an OCB mode, and the like that use a change in retardation by voltage application may be applied. Is possible.

  Further, in the present embodiment, the description has been given by exemplifying the configuration of normally black that mainly displays black when no voltage is applied. This configuration can be realized by laminating a circularly polarizing plate and a display layer having no birefringence in the in-plane direction when no voltage is applied. In this configuration, the circularly polarizing plate is replaced with a normal linear polarizing plate. Therefore, a normally white configuration may be adopted in which white display is obtained when no voltage is applied.

  Alternatively, a uniaxial retardation plate or the like may be laminated on any of these configurations to display a chromatic color when no voltage is applied. In this case, black or white display can be obtained by deforming the liquid crystal molecular arrangement in a direction to cancel the retardation amount of the laminated uniaxial retardation plate by applying a voltage.

  In addition, the present invention can be applied to any element that can realize brightness modulation and hue modulation with one pixel, and therefore, a liquid crystal mode, a guest host mode, a selective reflection mode, and the like in a twisted alignment state such as an STN mode. Various modes can be applied.

  By the way, in the explanation so far, the ECB effect of the liquid crystal has been described in detail. However, the basic idea of the present invention is that some pixels perform color display by applying a color filter to the monochrome display mode and other pixels use a display mode in which the hue can be changed. Therefore, the present invention is not limited to the configuration using the ECB effect described above, and can be applied to any color display device as long as the above display is possible.

For example,
(1) A color display device that changes the air gap distance of the interference layer by mechanical modulation,
(2) There is a color display device that switches between display and non-display by moving colored particles. Hereinafter, such a color display device will be described.

  (1) is for example SID97Digest p. 71. The interference color is switched between display and non-display by changing the gap distance from the substrate. Here, the deformable aluminum thin film is switched on and off by approaching and leaving the substrate by voltage control from the outside. Further, since the coloring principle at this time uses interference, the same argument as the above-described coloring by interference using the ECB of the liquid crystal holds.

  Therefore, even in the gap distance modulation element which is such a color display element, the optical properties can be changed by an externally controllable modulation means such as a voltage, and between the maximum brightness and the minimum brightness that the element can take. Is provided with a modulation area in which brightness can be changed by the modulation means, and a modulation area in which a plurality of hues that can be taken by the element can be changed by the modulation means.

  Then, the unit pixel is divided into a plurality of sub-pixels for such an element, and at least one of the plurality of sub-pixels can perform color display using a modulation region based on hue change. And the second sub-pixel (group) having a color filter layer enables high light utilization efficiency and multicolor display in exactly the same manner as the above-described color liquid crystal element. A color display element can be realized.

  For (2), for example, a particle movement type display element described in JP-A-11-202804 is preferably used. This example uses electrophoretic properties to switch between display and non-display by moving colored charged electrophoretic particles horizontally with the substrate surface in a transparent insulating liquid by applying a voltage between the collect electrode and the display electrode. Is what you do.

  Moreover, it is good also as a structure which applies this and uses two types of color particles. That is, two types of display electrodes and two collect electrodes arranged at positions substantially overlapping each other as viewed from the observer, two different charging polarities and colors, and at least one of which is translucent In a state where all of the two kinds of charged particles are gathered on the collect electrode, or in a state where all the two kinds of charged particles are arranged on the display electrode, or one of the particles is arranged on the display electrode and the other particle is on the collect electrode. A unit cell including a driving unit capable of forming an aggregated state or an intermediate state thereof may be used.

  Here, consider a configuration in which the combination of two types of electrophoretic particle colors in a unit cell is, for example, blue and red. In this case, when white display is performed, the two types of particles may be driven so as to be in a state where all of the particles are gathered on the collect electrode, and the display electrode may be exposed. In the case of monochromatic display of red or blue, the monochromatic color may be displayed by disposing only desired monochromatic particles on the display electrode in the unit cell.

  For example, in the case of blue display, blue particles may be arranged on the display electrode to form a light absorption layer, and red particles may be collected on the collector electrode. On the other hand, in the case of black display, by arranging all the particles on the display electrode and forming a light absorption layer, the particles pass through the absorption layers of the red particles and the blue particles formed on the first electrode and the second electrode, respectively. It becomes black by subtractive color mixture. In the case of halftone display, only a part of the particles during black display need be arranged on the display electrode. As a result, the unit cell can perform hue modulation between chromatic colors of red and blue, and lightness modulation by displaying white, black, and halftone.

  Thus, while using a medium having a brightness change range in which the brightness is changed by the modulation means and a hue change range in which the hue is changed by the modulation means, the unit pixel is divided into sub-pixels, and the pixel is based on the hue change. The first sub-pixel (group) that performs color display using the modulation region and the second sub-pixel (group) provided with the color filter layer are completely different from the color liquid crystal element described above. Similarly, a color display element capable of high light utilization efficiency and multicolor display can be realized.

(Example)
Hereinafter, the present invention will be described in detail using examples.

  In this embodiment, the following is used as a common element structure.

  The basic structure of the liquid crystal layer is a liquid crystal material having a negative dielectric anisotropy Δε as a liquid crystal material between two glass substrates subjected to vertical alignment treatment (Merck, model name MLC-6608). To form. At this time, the cell thickness is changed so as to optimize the retardation according to the embodiment.

  As a substrate structure to be used, an active matrix substrate in which TFTs are arranged on one substrate is used, and a substrate in which color filters are arranged is used as the other substrate. The pixel shape and color filter configuration at this time are changed according to the embodiment. The thickness of the color filter is 1 micron unless otherwise specified.

  In addition, an aluminum electrode is used for the pixel electrode on the TFT side, and a reflection type structure is adopted. At this time, a transflective structure is also prepared in which a transmissive pixel using an ITO electrode is used as a pixel electrode on the TFT side according to the embodiment.

  In addition, a broadband λ / 4 plate (a phase compensation plate that can substantially satisfy a ¼ wavelength condition in the visible light region) is disposed between the upper substrate (color filter substrate) and the polarizing plate as a phase compensation plate. . As a result, in a reflective display, a normally black configuration is obtained in which a dark state is obtained when no voltage is applied and a bright state is obtained when a voltage is applied.

(Comparative example)
For comparison, an ECB type active matrix liquid crystal display panel (liquid crystal display element) having a diagonal size of 12 inches and a pixel number of 600 × 800 is used. This pixel pitch is about 300 μm, each pixel is divided into three, and red, green, and blue color filters are respectively arranged. The thickness of the liquid crystal layer is adjusted to 3 microns so that the center wavelength of reflection spectral characteristics when a ± 5 V voltage is applied is 550 nm and the retardation amount is 138 nm.

  As shown in FIG. 9, the cell structure at this time is such that a vertical alignment film (not shown) is applied on the surface of the transparent electrodes 4 and 6, and the tilt direction of the liquid crystal molecules when a voltage is applied is the absorption axis of the polarizing plate 1. On the other hand, a pretilt angle of about 1 degree from the substrate normal is given to the vertical alignment film in that direction so as to be 45 degrees. A cell is formed by laminating upper and lower substrates 3 and 7, and when a liquid crystal material having a negative dielectric anisotropy Δε is injected as a liquid crystal material (MLC, model name: MLC-6608), liquid crystal is used when no voltage is applied. 5 is oriented perpendicular to the substrate surface. In the figure, reference numeral 2 denotes a phase compensation film.

  When an image is displayed on such a liquid crystal display element by varying the voltage, continuous tone colors corresponding to the applied voltage can be obtained for each of the RGB sub-pixels, thereby enabling full color display. However, in such a configuration, the reflectance is as low as 16%.

(Example 1)
In the first embodiment, an active matrix substrate having a diagonal size of 12 inches and a pixel number of 600 × 800 is used as the active matrix substrate. Each pixel is divided into six sub-pixels, and six types of color filters are used: red (R), green (G), blue (B), yellow (Y), magenta (M), and cyan (C). 6 color filters are formed by repeating the photolithography process six times.

  By adjusting the thickness of the liquid crystal layer to 10 microns, the three primary colors can be displayed by retardation. For example, red is displayed at 2.82V, blue is displayed at 3.15V, and green is displayed at 6.2V. With such a liquid crystal display element, an image can be displayed by changing the voltage. The range from 0V to 2.5V can be continuously modulated in brightness.

  When 2.5 V is applied to all the pixels, a white display is obtained. The reflectance at this time is about 25%, which shows that it is superior to the comparative example. In addition, a monochrome continuous tone display can be obtained by applying a voltage of 2.5 V or less to all the pixels.

  Next, the red display state will be described. For red, a continuous gradation amount can be obtained by changing the voltage value applied to the R pixel from 0V to 2.5V. A red display can also be obtained by applying 2.82 V to the Y pixel or the M pixel. Alternatively, even if 3.0 V is applied to the Y pixel and the liquid crystal layer is set to display magenta, a red display can be obtained by the subtractive color mixing effect with the yellow color filter.

  Here, as described above, the maximum luminance state of red can be obtained by setting both the Y and M pixels to display red and setting the R pixel to the maximum luminance. When the maximum luminance is set to 1, luminance modulation from 0 to 1/3 is performed by arbitrarily modulating the R pixel by displaying black in both Y / M. Further, in the luminance modulation in the range of 1/3 to 2/3, the Y or M pixel is displayed in red and the R pixel is arbitrarily modulated. Further, in the luminance modulation in the range of 2/3 to 1, both Y / M pixels are displayed in red and the R pixel is arbitrarily modulated. As a result, a red continuous tone color can be obtained. In addition, by displaying other display colors in the same manner, it is possible to obtain continuous tone display using this element.

(Example 2)
In this embodiment, an active matrix substrate having the same 12 inch diagonal and 600 × 800 pixels as the above comparative example is used as the active matrix substrate. Each pixel is divided into six sub-pixels. As a display pixel, a red display pixel is P _R , and similarly, green, blue, yellow, magenta, and cyan pixels are P _G , P _B , P _Y , P _M , P _{Let C} be. Here, in Example 1, a color filter was obtained by a total of six photo processes using different color filter materials, but in this example, this color filter was obtained by the following three processes of YMC. Consists only of.

First, a yellow color filter to _{P R} pixel, _{P Y} pixel, _{P G} pixel. Then, a magenta color filter _{P M} pixel, _{P B} pixel, with respect to _{P R} pixel. Here, since it is already a yellow color filter is formed on the P _R pixel, the color filter is formed so as Y and M are stacked. Next, a cyan color filter _{P G} pixel, _{P B} pixel, with respect to _{P C} pixels. Incidentally, P _G pixel, P _B pixel, since the yellow color filters and magenta color filters respectively formed in the form a cyan color filter so as to stack against them. Finally, a flattening process is performed as necessary.

In this way, to form a color filter that transmits _{P R} pixel, _{P G} pixel, _{P B} pixel, _{P Y} pixel, _{P M} pixels, each red, green, blue, yellow, magenta and cyan to _{P C} pixel It becomes possible. By performing actual driving in the same manner as in the first embodiment, full color display can be performed.

(Example 3)
In this embodiment, an active matrix substrate having a diagonal size of 12 inches and a pixel number of 600 × 800 is used as the active matrix substrate. In addition, each pixel is divided into four sub-pixels, and four types of color filters, red (R), green (G), magenta (M), and cyan (C), are used, and the photolithography process is repeated four times. Four color filters are formed.

  Further, by adjusting the thickness of the liquid crystal layer to 10 microns, the three primary colors can be displayed by retardation. For example, red is displayed at 2.82V, blue is displayed at 3.15V, and green is displayed at 6.2V. With such a liquid crystal display element, an image can be displayed by changing the voltage. The range from 0 V to 2.5 V is a region where the brightness can be continuously modulated.

  For example, in the case of red continuous gradation, when the maximum luminance is 1, from 0 to 1/2, the G, M, and C subpixels are displayed in black, and continuous gradation display is performed with R pixels. Further, from 1/2 to 1, a red luminance is displayed by the M subpixel to obtain a luminance of 1/2, and a continuous gradation display is performed by the R subpixel. At this time, the G and C subpixels are displayed in black.

  In the green continuous tone, when the maximum luminance is 1, the R, M, and C subpixels are displayed in black from 0 to 1/2, and the continuous tone display is performed with G pixels. From 1/2 to 1, green is displayed by the C subpixel to obtain 1/2 luminance, and continuous gradation display is performed by the G subpixel. At this time, the R and C subpixels are displayed in black.

  Further, the blue gradation display can be obtained by setting the M or C subpixel to blue display when the maximum luminance is 1. The other pixels are black. Maximum luminance 1 can be obtained by simultaneously displaying M and C pixels in blue. At this time, R and other pixels are black. Thereby, the blue display can obtain three gradations.

  In this embodiment, full-color display is not possible with these, and in particular, blue gradation display capability is insufficient, but it is possible to obtain a display state close to full color in view of human visibility characteristics. Become.

Example 4
When the substrate used in Example 3 is changed from a 12-inch substrate to a 3.5-inch substrate and the same display is performed, almost no graininess is visually observed, and a display that can be said to be almost full color can be obtained. It becomes possible.

(Example 5)
Of the pixels used in the first embodiment, each of the RGB sub-pixels is divided into two parts, one using a reflective substrate similar to that in the first embodiment and the other using an ITO electrode, thereby obtaining a transflective liquid crystal display element. .

  The cell thickness of the reflecting portion in the configuration of this example is 10 microns as in the first example. On the other hand, the cell thickness capable of realizing the necessary retardation amount in the transmission mode is 5 microns. That is, in this embodiment, unlike the normal transflective display element, the reflection mode is set thicker.

  The reflective portion can be displayed in full color by being driven in the same manner as in the first embodiment. On the other hand, if the polarizing plate is set to crossed Nicols with respect to the transmitting portion, a normally black mode is displayed in which black is displayed when no voltage is applied. Therefore, both the transmission part and the reflection part may be set to 10 microns. Of course, a multi-gap configuration may be used. In either case, it is possible to perform full color display while ensuring high contrast in both the transmissive part and the reflective part.

(Example 6)
Regarding the color filter used in Example 5, when the thickness of the RGB color filter in the transmissive part is changed from 1 micron to 3 microns to produce a liquid crystal element, the color purity of the three primary colors in the transmissive part can be increased. At this time, it is possible to set the cell thickness of the transmission portion to be thin by appropriately adjusting the flatness. That is, by increasing the color filter of the transmissive part, high color purity and a thin cell thickness can be realized at the same time, which can contribute to improving the response speed of the transmissive part.

(Example 7)
With respect to the color filter used in the first embodiment, an RGB color filter is disposed in three sub-pixels, and a bright color display can be obtained by adopting a configuration in which any or all of the other three sub-pixels are not used. Can be obtained.

  For example, let us consider a case in which an element including five subpixels having RGBYC color filters and one subpixel not having a color filter is used except for the M color filter in the first embodiment.

  In this case, a sub-pixel having no color filter obtains black display at 0 V, red display at 2.82 V, magenta display at 3.0 V, and blue display at 3.15 V due to the coloring phenomenon due to the ECB effect. It becomes possible. That is, a display state similar to that of a sub-pixel having a color filter can be obtained, and thus full-color display is possible even with this configuration.

  In the same way, color display can be performed by the coloring phenomenon due to the ECB effect without the Y and C color filters, so that the number of color filters can be reduced from the first embodiment.

  As a result, the load of the color filter forming process is reduced and a bright display can be obtained.

(Example 8)
In this embodiment, each pixel is divided into six sub-pixels, and each pixel is provided with red, green, blue, and magenta color filters. The magenta pixel is divided into three. The red display pixel is P _R , and the green, blue, and magenta pixels are P _G , P _B , P _M1 , P _M2 , and P _M3 , respectively. The area ratio of each pixel is P _R : P _G : P _B : P _M1 : P _M2 : P _M3 = 1: 8: 1: 1: 2: 4. In this embodiment, this color filter is configured by only three types of processes of YMC as follows.

_First, P B, to form a cyan color filter to _{P G} pixels. Then, a magenta color filter _{P M} pixel, _{P B} pixel, with respect to _{P R} pixel. Since already the cyan color filter on P _B pixels are formed, a color filter is formed to C and M are stacked. Next, a yellow color filter _{P G} pixel, relative to _{P R} pixel. Incidentally, P _G pixel, P _R pixel, since it is the cyan color filter and magenta color filters respectively formed in the form a yellow color filter so that stacked against them. Finally, a flattening process is performed as necessary.

In this way, P _R pixel, it is possible to form P _G pixel, P _B pixel, a color filter for each transmitting red, green, blue and magenta to P _M pixels by three photo process. The actual drive can be performed using the method described in WO2004 / 042687, and full color display can be performed.

  Further, by performing the planarization treatment, it is possible to obtain a flat substrate structure that is advantageous for uniforming the alignment state.

  Alternatively, when the flattening process is not performed, the magenta pixel has only one color filter layer and the other red, green, and blue pixels have two layers, so that only the magenta pixel color filter has a thin film thickness. Become. In the liquid crystal element using this, the thickness of the liquid crystal layer is the thickest in magenta. By doing this, it becomes possible to set the cell thickness of the magenta pixel that requires the largest amount of retardation to be thick. The same effect can also be obtained by performing a flattening process that leaves a step slightly for each color filter.

Example 9
In this embodiment, each pixel is divided into nine sub-pixels, and each pixel is provided with a color filter of red, green, blue, and magenta. The magenta pixel is divided into three. Red, green, and blue are each divided into two parts, one of which uses ITO for the upper and lower electrodes so that transmissive display is possible, and the other one is reflective so that reflective display is possible An electrode is used.

At this time, the magenta pixels are set to P _M1 , P _M2 , and P _M3 . In addition, the red display pixel in the transmissive display pixel is P _{R_T} , and green and blue are P _{G_T} and P _{B_T} , respectively. The red display pixel in the reflective display pixel is P _{R_R} , and green and blue are P and P, respectively. _{Let G_R} and _{PB_R} . Area ratio of each pixel at this _{time, P R_T: P G_T: P} B_T: P R_R: P G_R: P B_R: P M1: P M2: P M3 = 1: 1: 1: 1: 8: 1: 1 : 2: 4. Here, in order to perform four types of color display, it is possible to obtain a color filter by a total of four photo processes using different color filter materials. In this embodiment, this color filter is As shown in the figure, it is constituted by only three types of processes of YMC.

First, a cyan color filter is formed for P _{B_T} , P _{B_R} , P _{G_T} , and P _{G_R} pixels. Then, _{P M pixel, P B_T,} P _{B_R pixel,} P _{R_T,} to form a magenta color filter to _{P r_r} pixels. Here, since the cyan color filter is already formed on the P _{B_T} and P _{B_R} pixels, the color filter is formed so that C and M are stacked. Next, yellow color filters are formed on the P _{G_T} , P _{G_R} pixels, P _{R_T} , and P _{R_R} pixels. _{Incidentally,} P _{G_T, P G_r pixel,} P _{R_T,} since _{P r_r} pixel, respectively a cyan color filter and magenta color filters in is formed to form a yellow color filter so that stacked against them. Finally, a flattening process is performed as necessary.

In this way, three _P R_T by a photo _process, a color filter that transmits _{P r_r pixel,} P _{G_T, P G_r pixel,} P _{B_T, P B_R} pixels, each red, green, blue and magenta to _{P M} pixel Can be formed. The actual drive can be performed using the method described in WO2004 / 042687, and full color display can be performed. Further, by providing a backlight, transflective display can be performed.

  Further, by performing the planarization treatment, it is possible to obtain a flat substrate structure that is advantageous for uniforming the alignment state.

  As described above, a bright reflective liquid crystal display element and a transflective liquid crystal display element can be realized by this embodiment. In this embodiment, the direct-view type reflective liquid crystal display element and the direct-view type transflective liquid crystal display element have been mainly described. The present invention can be applied to a liquid crystal display element such as a viewfinder using the system.

  Further, in this embodiment, a TFT is used as a drive substrate. Instead, a MIM is used, a substrate configuration is changed such as using a switching element formed on a semiconductor substrate, a simple matrix drive or a plasma addressing drive is used. Variations in the driving method can be made obvious.

  In this embodiment, the vertical alignment mode is mainly described. However, as described above, the mode is applicable to any mode as long as it uses a retardation change by voltage application, such as a parallel alignment mode, a HAN type mode, and an OCB mode. Is possible. It can also be applied to a liquid crystal mode in a twisted alignment state such as STN mode.

  Further, even when a color display element that changes the air gap as the medium of the interference layer by mechanical modulation is used instead of the liquid crystal display element having the ECB effect, the same effect as in this embodiment can be obtained. It is done. Further, even when a particle movement display element that moves a plurality of particles, which are media based on the configuration described in the embodiment, by applying a voltage, is used as the color display device, the same effect as in this embodiment can be obtained.

The figure which shows the structure of 1 pixel of the color display element (liquid crystal display element) used for the color display apparatus concerning the best form for implementing this invention. The figure showing a RGB color solid. The figure explaining the display range obtained by a YMC color filter in the said RGB color solid. The figure showing the range which the said color display element can display with a yellow subpixel in the said RGB color solid. The figure showing the range which the said color display element can display by the combination of a yellow subpixel and a RGB subpixel in the said RGB color solid. The figure showing the lattice point which the said color display element can display in a YMC subpixel in the said RGB color solid. The figure explaining that the said color display element implement | achieves three primary colors by a YMC color filter. FIG. 6 is a diagram illustrating an example of a configuration of a color filter of the color display element. FIG. 5 illustrates a structure of a liquid crystal display element according to a comparative example of the liquid crystal display element. The figure showing the change on a chromaticity diagram when the amount of retardation changes.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polarizing plate 2 Phase compensation film 3 Glass 4 Transparent electrode 5 Liquid crystal 6 Transparent electrode 7 Reflector 20 Pixel 21-23 Second subpixel 24-26 First subpixel

Claims (12)

The unit pixel is composed of a plurality of subpixels including a plurality of first subpixels and a plurality of second subpixels provided with color filters, and the optical properties of each subpixel can be changed according to the applied voltage. A color display device comprising a color display element in which a medium is arranged,
The plurality of first sub-pixels have optical properties of the medium, a range in which the lightness of light passing through the medium changes, and light passing through the medium exhibits a chromatic color, and the hue of the chromatic color changes. Means for applying a voltage that modulates in a range;
Means for applying, to the plurality of second subpixels, a voltage that modulates the optical properties of the medium in a range in which the brightness of light passing through the medium changes;
A color display device comprising two color filters selected from three colors of red, green, and blue, respectively, in at least two of the plurality of second subpixels.   The two-color filter having a complementary color relationship with each of the two color filters provided in the second sub-pixel is provided in at least two of the first sub-pixels. The color display device described in 1.   3. The color display device according to claim 2, wherein the color filter color of the first subpixel is cyan and magenta, and the color filter color of the second subpixel is red and green.   The color display element includes a pair of substrates arranged opposite to each other, and a liquid crystal layer that is provided between the substrates and changes optical properties when a voltage is applied thereto, and an arrangement of liquid crystal molecules in the liquid crystal layer The plurality of pixels have a function of modulating incident polarization into a desired polarization state using a change in retardation due to change, and the plurality of pixels use a modulation region based on a change in hue according to a change in retardation due to a change in the alignment of the liquid crystal layer. 4. The color display device according to claim 1, comprising a first sub-pixel that performs color display and the second sub-pixel. 5.   5. The color display device according to claim 4, wherein the liquid crystal molecules of the liquid crystal layer have a negative dielectric anisotropy and are aligned substantially vertically when no voltage is applied.   The color display device according to claim 5, wherein the liquid crystal molecules are controlled to be inclined at least in two director directions having different optical axes when a voltage is applied.   5. The color display device according to claim 4, wherein the liquid crystal molecules of the liquid crystal layer are bend-aligned at least when a voltage is applied.   The color display device according to claim 4, wherein the liquid crystal molecules of the liquid crystal layer are aligned in a direction substantially parallel to the substrate when no voltage is applied.   The color display device according to any one of claims 4 to 8, wherein the color display element is a reflective color liquid crystal display element in which a single polarizing plate is used.   The color display element includes at least a light irradiation means, a pair of substrates provided with electrodes, and a pair of polarizing plates. At least one of the substrates includes a light-reflective first region and a light-transmissive second region. The color display device according to claim 1, wherein the color display device is a transflective display element having a region.   The plurality of second subpixels include three second subpixels each having color filters of three colors of red, green, and blue, and the first subpixel is any one of yellow, magenta, and cyan The color display device according to claim 1, wherein a single color complementary color filter is provided. 2. The color filter according to claim 1, wherein at least one of the three color filters used for the second subpixel is a color filter in which any two color filters of yellow, magenta, and cyan are stacked. The color display device described.

Images