TW200837427A - Liquid crystal display device and electronic paper using the same - Google Patents

Abstract

The present invention relates to a liquid crystal display device which drives liquid crystal compositions showing a cholesteric phase to display an image, and an electronic paper using the same. It is an object of the invention to provide a liquid crystal display device which can realize the ease of fabrication and the reduction in fabrication costs, and an electronic paper using the same. A liquid crystal display device is configured to have a blue liquid crystal display element in which blue liquid crystals selectively reflecting blue light are sealed between counter substrates, a green liquid crystal display element in which green liquid crystals selectively reflecting green light are sealed between counter substrates, and a red liquid crystal display element in which red liquid crystals selectively reflecting red light are sealed between counter substrates, being laminated in this order from the display surface side, whereby a relation Δ ε B > ΔεG > ΔεR is satisfied where the magnitude of dielectric anisotropy of the blue liquid crystal is ΔεB, the magnitude of dielectric anisotropy of the green liquid crystal is ΔεG, and the magnitude of dielectric anisotropy of the red liquid crystal is ΔεR.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device for driving a liquid crystal material, particularly for driving a liquid crystal composition capable of displaying a cholesteric phase, and using the liquid crystal display device Electronic paper. [Prior Art 3] In recent years, in various enterprises and universities, the development of electronic paper is prospering 10 . It is expected that the field of application of electronic paper is based on electronic books, and there are mobile devices such as sub-displays for mobile terminal devices and display units for 1C cards. One of the display devices used in electronic papers is a liquid crystal display device using a liquid crystal composition (referred to as cholesteric liquid crystal or chiral twisted liquid crystal, hereinafter referred to as cholesteric liquid crystal) which can form a cholesterol phase. Cholesterol liquid 15 crystal, with semi-permanent display retention characteristics (image display without power supply; memory), vivid color display characteristics, high contrast characteristics and high resolution characteristics. According to the invention, the liquid crystal display device using the cholesteric liquid crystal has a structure in which a liquid crystal display element for each color of a plurality of layers is laminated for color display. In this case, the same composition of the cholesteric liquid crystal is generally used, and therefore the panel pitch of the liquid crystal display element and the driving voltage of the liquid crystal must be different for each color. 5 200837427 For example, in order to simplify the manufacturing process and use a liquid crystal display panel in which the panel pitch of the liquid crystal display elements for each color is set to be about the same type, the driving voltage applied to the liquid crystal must be made every One color is different. For example, the red liquid crystal display element is about 19V, the green liquid crystal display element 5 is about 25V, and the blue liquid crystal display element is about 3IV. Therefore, it is necessary to separately provide a driving circuit for each color, which constitutes a factor that hinders the cost reduction of the liquid crystal display device. On the other hand, in order to make the driving circuits of the liquid crystals for the respective colors common, and to set the driving voltages of the liquid crystals of the liquid crystal display elements for the respective colors to be about the same, it is necessary to change the panel pitch of the liquid crystal display elements for each color. . For example, in red, green, and blue liquid crystal display elements, the panel pitch is about 6.5/m, about 5//m, and about 4/zm, respectively. Therefore, it is necessary to produce a liquid crystal display panel for each color, and there is a problem that a complicated manufacturing process has to be performed. 15 As described above, the conventional liquid crystal display device using a layered type of cholesteric liquid crystal has to perform complicated manufacturing processes, and it is difficult to perform complicated manufacturing processes. Achieve manufacturing ease and reduce manufacturing costs. SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device which can achieve ease of manufacture and which can attain a reduction in manufacturing cost, and 20 electronic paper using the liquid crystal display device. The above-mentioned object is achieved by a liquid crystal display device in which a plurality of liquid crystal display elements are laminated, and the plurality of liquid crystal display elements are selectively reflected between the opposite substrates. a dielectric liquid having a wavelength of 6 200837427 - 5 and selectively reflecting a dielectric anisotropy of a liquid crystal having a relatively short wavelength of light, and a dielectric anisotropy of a liquid crystal selectively reflecting light having a relatively long wavelength Still big. Further, the liquid crystal display device of the present invention described above is characterized in that the plural liquid crystal contains a liquid crystal which forms a cholesterol phase. Further, the liquid crystal display device of the present invention is characterized in that a blue liquid crystal display element which is filled with a blue liquid crystal selectively reflecting blue light and which is selectively interposed between the opposite substrates is selectively provided. a green liquid crystal display element in which a green light-reflecting green light is filled with a liquid crystal between a counter substrate, and a red liquid crystal display element in which a red liquid crystal selectively reflects red light is filled between the opposite substrates, and The magnitude of the dielectric anisotropy of the blue liquid crystal is ε Β , the dielectric anisotropy of the green liquid crystal is Δ ε 〇 , and the dielectric anisotropy of the red liquid crystal is set to When Δ ε r , the relationship of Δ ε Β > Δ a eR > is satisfied. Further, the liquid crystal display device of the present invention is characterized in that the blue liquid crystal display element, the green liquid crystal display element, and the red liquid crystal display element are sequentially laminated from the display side. Further, the liquid crystal display device of the present invention is characterized in that the optical rotatory property of the green liquid crystal is different from the optical rotatory properties of the blue liquid crystal and the red liquid crystal. 20 The above object is achieved by an electronic paper having the following features for displaying an image and including the above liquid crystal display element. Advantageous Effects of Invention According to the present invention, it is possible to achieve ease of manufacture of a liquid crystal display device, and it is possible to achieve a reduction in manufacturing cost. 7 200837427 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing a liquid crystal display device according to a first embodiment of the present invention. Fig. 2(a) and Fig. 2(b) are schematic diagrams showing the cross-sectional structure of a liquid crystal display element of a liquid crystal display device constructed in accordance with a first embodiment of the present invention. Fig. 3 is a view showing the relationship between Δ ε and HT voltage of the cholesteric liquid crystal of the liquid crystal display device constructed in the first embodiment of the present invention. Fig. 4 is a view showing the schematic configuration of a liquid crystal display device constructed in accordance with a second embodiment of the present invention. Fig. 5 is a schematic cross-sectional view showing a liquid crystal display device constructed in accordance with a second embodiment of the present invention. Fig. 6 is a view showing an example of a reflection spectrum of a parallel spiral state of a liquid crystal display device constructed in accordance with a second embodiment of the present invention. Fig. 7 (a) and (b) show a driving method of a liquid crystal display device constructed in accordance with a second embodiment of the present invention. Fig. 8 shows an example of the voltage-reflectance characteristics of the cholesteric liquid crystal. Fig. 9 (a) to (c) show specific examples of the electronic paper £1 having the liquid crystal display device 1 constructed in the second embodiment of the present invention. C embodiment] 20 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [First Embodiment] A liquid crystal display device constructed according to a third embodiment of the present invention and a liquid crystal display device using the same will be described with reference to FIGS. 1 to 3 . Electronic paper. Fig. 1 is a schematic diagram showing a liquid crystal display using a cholesteric liquid crystal for full color display. 8 200837427 A cross-sectional structure of the display device 51. The liquid crystal display device 51 has a structure in which a liquid crystal display element 46b for blue (β), a liquid crystal display element 46g for green (G), and a liquid crystal display element 46r for red (R) are laminated in this order from the display surface. In the drawing, the side of the substrate 47b on the upper side is a display surface, and the external light source (solid arrow) 5 is incident from the upper side of the substrate 47b toward the display surface. Further, the observer's eye and its observation direction (dashed arrow) are patterned above the substrate 47b. The B liquid crystal display element 46b has a blue (b) liquid crystal 43b which has been sealed between the pair of upper and lower substrates 47b and 49b, and a pulse wave voltage source 41b which can apply a predetermined pulse wave voltage to the B liquid crystal 43b. The liquid crystal display element 46g for G has a green (G) liquid crystal 43g which is filled between a pair of upper and lower substrates 47g and 49g, and a pulse wave voltage source 41g which can apply a predetermined pulse wave voltage to the g liquid crystal 43g. The liquid crystal display element 46r for R has a green liquid crystal 43γ which has been filled between the pair of upper and lower substrates 47r and 49r, and a pulse wave voltage source 41r which can apply a predetermined pulse wave voltage to the R liquid crystal 43r. Although omitted from the drawings, at the interface side where the liquid crystals 43 of the respective upper and lower substrates 47 and 49 are in contact with each other, a plurality of electrodes for applying pulse wave voltages from the respective pulse wave voltage sources 41 to the liquid crystals 43 are formed. Further, an alignment film or an insulating film may be formed on the interface side in contact with the liquid crystals 43 of the respective upper and lower substrates 47, 49 as needed. A light absorbing layer 20 is disposed on the inner surface of the substrate 49τ under the liquid crystal display element 46r for R. The cholesteric liquid crystal system used in the liquid crystal layers 43b, 43g, and 43r for each of the yttrium, G, and R is added in a tens of weight percent chiral (palm) additive (also referred to as a hand material). A liquid crystal mixture of a torsional liquid crystal. When the torsional liquid crystal contains a chiral material in a large amount, a cholesterol phase in which the twisted liquid crystal 9 200837427 molecule is strongly twisted into a spiral shape can be formed. Therefore, cholesteric liquid crystal is also called chiral twisting liquid crystal. Cholesterol liquid crystal has double stability (memory), which can be in the form of a parallel planar state, a vertical spiral 5 (focal-conic state) or a parallel spiral state and a vertical spiral state depending on the electric field intensity applied to the liquid crystal. Any of the states of the sexual state, once formed in a parallel spiral state, a vertical spiral state, or an intermediate state in which such states are mixed, is then stable even in the absence of an electric field to maintain its state. In the parallel spiral state, a predetermined high voltage is applied between the upper and lower substrates 47, 1049, and after a strong electric field is applied to the liquid crystal layer 43, the electric field is sharply set to zero and is paid. The vertical spiral state is obtained, for example, by applying a predetermined voltage lower than the above-described high voltage between the upper and lower substrates 47 and 49, and applying an electric field to the liquid crystal layer 43, and then rapidly setting the electric field to zero. In the intermediate state of the parallel spiral state and the vertical spiral state, for example, a voltage lower than a voltage at which a vertical spiral state can be obtained is applied between the upper and lower substrates 47 and 49, and an electric field is applied to the liquid crystal layer 43 and then sharply The ground is obtained by setting the electric field to zero. The display principle of the liquid crystal display device 51 using this cholesteric liquid crystal will be described by taking the B display portion 4 6 b as an example. Fig. 2(a) shows the alignment state of the liquid crystal molecules 33 in the parallel spiral state of the B liquid crystal layer 43b of the B display portion 46b. As shown in Fig. 2(a), the liquid crystal molecules 33 in the parallel spiral state are sequentially rotated toward the substrate thickness direction to form a spiral structure, and the spiral axis of the spiral structure is about perpendicular to the substrate surface. In the parallel spiral state, the light in the wavelength region is selectively reflected in the liquid crystal layer in response to the predetermined pitch of the liquid crystal molecules 33. At this time, the reflected light is a circularly polarized light of one of the left and right sides in response to the chirality of the spiral pitch, and the other light passes through the liquid crystal layer. Since the natural light is in a state in which the left and right circularly polarized light is mixed, it is understood that once the natural light is incident on the liquid crystal layer in the parallel spiral state, 50% of the incident light is reflected in the predetermined wavelength region, and 50% is transmitted. When the average refractive index of the liquid crystal layer is η and the pitch of the spiral is p, the wavelength λ at which the reflection is maximum can be expressed by λ = η·ρ. As a result, the blue light is selectively reflected when the liquid crystal layer 43b is in the parallel spiral state between the display portion 46b, and the average refractive index 11 and the pitch 10 are determined to be, for example, I = 480 nm. The average refractive index n can be adjusted by selecting the liquid crystal material and the hand material, and the screw pitch ρ can be adjusted by adjusting the content of the hand material. Fig. 2(b) shows the alignment state of the liquid crystal molecules 33 in the vertical spiral shape of the B liquid crystal layer 43b of the B display portion 46b. As shown in Fig. 2(b), the liquid crystal molecules 33 which are spirally inclined in the vertical direction 15 are sequentially rotated toward the inner surface direction of the substrate to form a spiral structure, and the spiral axis of the spiral structure is approximately parallel to the substrate surface. In the case of the vertical spiral state, the liquid crystal layer 43b for B loses the selectivity of the reflection wavelength, and the incident light is almost completely transmitted. The transmitted light is absorbed by the light absorbing layer 45 disposed on the inner surface of the substrate 49r under the R display portion 4&, so that dark (black) display can be realized. 2〇 If the parallel spiral state is mixed with the vertical spiral state, the ratio of the reflected light to the transmitted light is adjusted to change the intensity of the reflected light. Therefore, an intermediate multi-gray scale display corresponding to the intensity of the reflected light can be realized. As described above, the cholesteric liquid crystal can control the amount of reflection of light by the alignment state of the liquid crystal molecules 33 11 200837427 which are twisted into a spiral shape. Similarly to the above-described liquid crystal layer 43b for B, a liquid crystal display in which a green or red light can be selectively reflected in a parallel spiral state is sealed in a liquid crystal layer 43g for G and a liquid crystal layer 43r for R to produce a liquid crystal display of a full color display. Element 51. The liquid crystal display element 51 has a memory level and can display full color without consuming power even when the surface is rewritten. According to the liquid crystal display device 51 of the present embodiment, the ease of manufacture can be achieved, and the manufacturing cost can be reduced. Therefore, the liquid crystal display device 51 has the following characteristic structure. (1) First, at least two liquid crystals 43 containing a liquid crystal forming a cholesterol phase and selectively reflecting light of different wavelengths are selectively laminated (hereinafter, an additional word "s" is added for a relatively short selection wavelength, for selecting a wavelength The relatively long addition of the additional word "1") encloses at least two of the liquid crystal display elements 46s, 461 between the individual substrates 47, 49, respectively. And selectively reflecting the magnitude (absolute value) of the dielectric anisotropy Δ ε s of the liquid crystal 43s of the relatively short wavelength light, and selectively controlling the dielectric anisotropy of the liquid crystal 431 of the light having a relatively long wavelength. △ The size of £s is still large. That is, Δ £s > a (2) adjusts the values of Δ ε 8 and ε ε by Δ ε s > Δ ε 1 to make the panel pitch of the liquid crystal display elements 46s and 461 (also called cell pitch, liquid crystal) Layer thickness) is about the same. 20 (3) Further, the value of Δ ε Δ ε 1 is adjusted under the condition of Δ ε s > Δ ε 1 so that the driving voltage ranges of the liquid crystals 43s and 431 are approximately the same. (4) More specifically, the liquid crystal display device 51 is filled with blue liquid crystals 4313 that selectively reflect blue light from the display surface side in the blue between the opposite panels 4 7 b and 4 9 b. The liquid crystal display element 46 6b has been used to selectively reflect the green liquid crystal display element 46g between the counter substrates 47g and 49g, which is selectively inverted 12200837427, and has been selectively reflected red light. The red liquid crystal 43r is filled in the order of the red liquid crystal display element 46r between the counter substrate 47r and 4%, and the dielectric anisotropy of the blue liquid crystal 43b is not Δε b. When the size of the dielectric anisotropy of the green liquid crystal 43g is Δ £ g and the dielectric anisotropy of the red liquid crystal 43γ is not Δ ε, the relationship of ' satisfying Δ ε Β Α ε ε r is satisfied. . (5) The values of Δ ε β, Δ ε G and Δ ε R are adjusted by the condition of Δ ε β > Δ £ g > Δ ε R. The panel pitches of the liquid crystal display elements 46b, 46g, and 46r are approximately the same. (6) The values of Δ and Δ eR are adjusted under the condition of Δ ε Β > Δ eR so that the driving voltage ranges of the blue liquid crystal 43b, the green liquid crystal 43g, and the red liquid crystal 43r are approximately the same. In the following, based on the characteristic structures of the above (1) to (6), the reason why the easy-to-use I5 is achieved and the manufacturing cost is reduced can be explained. The inventors of the present invention investigated in detail the dielectric anisotropy Δ ε (absolute value) of the liquid crystal selectively reflecting light of a predetermined wavelength in a parallel spiral state and the case where the driving voltage of the liquid crystal is driven to rewrite the image The relationship between the reset voltages necessary for resetting. The reset voltage is a voltage which is 20 when the liquid crystal is set to the vertical spiral state, and is simply referred to as "HT voltage" hereinafter. The third graph is a graph showing the relationship between the dielectric anisotropy Δ e of the liquid crystal and the voltage of the town. In Fig. 3, the horizontal axis indicates the dielectric anisotropy Δ in the logarithm to the linear Ητ voltage. The Ητ voltage is a (four) value of each panel pitch when the pulse wave voltage of the pulse wave plate s is applied to the pulse wave. 13 200837427 Also in this embodiment, a liquid crystal material having a positive dielectric anisotropy is used. In Fig. 3, the 'four-corner () mark indicates liquid crystal for red (8) color, the diamond (♦) mark indicates liquid crystal for green (G) color, and the triangular mark indicates liquid crystal for blue (B) color. As can be seen from Fig. 3, the larger the dielectric anisotropy Δ 5 ε of the liquid crystal for any color, the more linearly the HT voltage is linearly displayed by the logarithm of the horizontal axis. Further, the longer the wavelength of the selectively reflected light is, the lower the ΗΤ voltage is. For example, if the panel pitch is set to 4#m and the ΗΤ drive voltage is set to 28V', △ ε r, Δ ε 〇, Δ ε b are set to the HT voltage of Fig. 3 = 10 7V (= 28/4) Just fine. That is, the dielectric anisotropy Δ es of the liquid crystal 43s of the liquid crystal display element 46s having a relatively short wavelength for the selectively reflected light is set to be relatively higher than the wavelength of the light for selective reflection. In the liquid crystal 431 of the long liquid crystal display element 461, the dielectric anisotropy Δ ε i is large, and the driving voltage and the panel pitch can be aligned to the liquid crystal display elements 15 46 s and 461 . When the predetermined reflection wavelength satisfies the relationship of Δ£(}> Δ ε Β > Δ ε R , the driving voltages and panels of the liquid crystal display elements 46b, 46g, and 46r that respectively reflect red, green, and blue light can be used. The pitch is as close as the same. Thus, according to the present embodiment, firstly, since the panel pitch of the plurality of liquid crystal display elements of the light of different wavelengths selectively reflected by 20 can be aligned to be about the same, the liquid crystal is filled. The manufacturing process of the liquid crystal display element of the project can use the same engineering without relying on the liquid crystal materials for the various colors of the seal. For example, in the liquid crystal filling by the vacuum injection method, the liquid crystal can be manufactured by the same engineering. The former empty panel, therefore, compared to 14 200837427, it is necessary to prepare three kinds of empty panels of conventional manufacturing engineering, and the invention is excellent in manufacturability and can be reduced in cost. Further, according to this embodiment, since it can be selectively The driving voltages of the plurality of liquid crystal display elements reflecting different wavelengths of light are aligned to be about the same, so that the conventional technique can be applied to each liquid crystal display element. The scanning electrode driving circuit to be provided is integrated in one, and the cost of the liquid crystal display device can be reduced. [Second embodiment] The second embodiment according to the present invention will be described using Figs. 4 to 9; The liquid crystal display device and the electronic paper using the liquid crystal display device. In the present embodiment, a liquid crystal display device 1 using cholesteric liquid crystals of blue (B), green (G), and red (R) will be described as an example. 4 is a view showing a schematic structure of a liquid crystal display device 1 constructed in accordance with the present embodiment. Fig. 5 is a schematic view showing a cross-sectional structure of the liquid crystal display device 1 cut in a line parallel to the horizontal direction of the figure in Fig. 4; As shown in FIGS. 4 and 5, the liquid crystal display device includes a liquid crystal display element Bb for B which selectively reflects blue light by reflecting blue (B) color light as a selected wavelength region in a parallel spiral state. In the parallel spiral state, the green (G) color light is used as the selective wavelength region to selectively reflect the green light, and the liquid crystal display element 6 § is used to reflect the red (R) color light in the parallel spiral state as the selected wavelength region. Selectively The liquid crystal display element 6r for R which emits red light. The liquid crystal display elements 6b, 6g, and 6r for B, G, and R are laminated in this order from the light incident surface (display surface). The liquid crystal display element 6b for B includes The pair of upper and lower substrates 15 200837427 7b, 9b and the B liquid crystal 3b which has been sealed between the two substrates 7b and 9b, and the B liquid crystal 3b have an adjustable average refractive index n or a spiral pitch p and are right-handed Light (chirality to the right) to selectively reflect blue light, and to reflect light of a right circularly polarized light that reflects blue in a parallel spiral, and transmits light outside, and is in a straight spiral state The dielectric liquid crystal of the present cholesteric liquid crystal has a dielectric anisotropy Δ ε b as shown in Fig. 3 as Δ ε 21 = 21 at HT voltage = 7V. The φ 液晶 liquid crystal display element 6g includes one of the upper and lower substrates 7g and 9g disposed in the opposite direction, and the liquid crystal 3g which has been filled between the two substrates 7g and 9 §, and the liquid crystal 3 § has an adjustable average refraction. The ratio η or the spiral pitch p is left-handed (chiral to the left) to selectively reflect green light, and the light of the left circularly polarized light is reflected by the parallel spiral, and the other light is transmitted, and It is composed of a cholesteric liquid crystal that transmits about all of the light in a vertical spiral state. The dielectric anisotropy Δ ε g of the present cholesteric liquid crystal is Δ ε β = 13.5 at ΗΤ voltage = 15 7V as shown in Fig. 3 . The liquid crystal display element 6r for φ R includes one of the upper and lower substrates 7r and 9r disposed opposite to each other, and the liquid crystal which has been filled in the both substrates 7r and R, and the liquid crystal for R has an adjustable average refractive index. η or a spiral pitch p and a right-handed optical property (hand to the right) to selectively reflect red light, and to reflect light of a right circularly polarized light of blue under a parallel spiral state 2〇 It is transmitted through a cholesteric liquid crystal that transmits about all of the light in a vertical spiral state. The dielectric anisotropy Δ eR of this cholesterol liquid 如 is Δ £ b = 9.5 at ΗΤ voltage = 7 ν as shown in Fig. 3 . Therefore, according to the liquid crystal display device of the present embodiment, the dielectric anisotropy of the liquid crystals 3b, 3g, and 3r of the respective colors 16 200837427 satisfies the relationship of Δ ε b > Δ e g > Δ ε r . Further, under the condition of ΔεΒ>Δε(}> Δε R , the values of ε B, Δ ε ^ and ε ε can be adjusted at HT voltage=7 V shown in Fig. 3, so that liquid crystal can be 5 The display elements 6b, 6] have a panel pitch of about the same, and the drive voltage ranges of the B liquid crystal 3b, the G liquid crystal 3g, and the R liquid crystal 43r can be set to be about the same. The components B, G, and R are used. Each of the liquid crystals 3b, 3g, and 3r of the cholesteric liquid crystal is added to the liquid crystal mixture of the torsional liquid crystal in a amount of 10 to 40% by weight of the chiral material. The addition ratio of the target material is the total of the torsional liquid crystal component and the chiral material. The value is set to 100% by weight. Various materials well known in the art can be used as the torsional liquid crystal. The refractive index anisotropy of the cholesteric liquid crystal is preferably 〇18 '^11-0.24. If it is an anisotropic refractive index An ratio When the range is small, the reflectance of each of the liquid crystals 3b, 3g, and 3r in the parallel spiral state becomes low, and if it is larger than the range of 15, the scattering reflection of the liquid crystals 3b, 3g, and 3r in the vertical spiral state becomes large. And the viscosity will also become higher and the reaction rate will be lowered. Also, the chiral material added to the liquid crystal of B and R for cholesteric liquid crystal The chiral material added to the cholesteric liquid crystal for G is an optical anisotropy which is different in optical rotation from each other. Therefore, the optical activity of the cholesteric liquid crystal for B and R is the same, and the optical rotation of the cholesteric liquid crystal for G 20 is different. The graph shows an example of the reflection spectrum of each of the liquid crystals 3b, 3g, and 3r in a parallel spiral state. The horizontal axis represents the wavelength of the reflected light (nnl), and the vertical axis represents the reflectance (white plate ratio; %). In the liquid crystal layer 3b for B The reflection spectrum is represented by a curve connecting the triangles (▲) in the figure. Similarly, the inverse spectrum of the liquid crystal layer 3g for G is reported in the figure by a curve connecting the square () marks, and for the R. The reflection spectrum of the liquid crystal layer 3r is indicated by a curve connecting the diamond (♦) marks in the figure. As shown in Fig. 6, the center wavelength of the reflection spectrum of the parallel spiral state of each of the liquid crystals 3b, 3g, and 3r is liquid crystals 3b and 3g. In the laminated structure of the liquid crystal display elements 6b, 6g, and 6r of B and G' R, the optical rotation of the liquid crystal layer 3g for G in the parallel spiral state and the liquid crystal layers 3b and 3r for the B and R are used. The optical rotation is different, so it is shown in Figure 6. In the region where the reflection spectrum is overlapped with green, green, and red, for example, the liquid crystal layer 3b for B and the liquid crystal layer 3r for R can reflect the light of the right circular polarization, and the liquid crystal layer 3g for G can reflect the light of the left circular polarization. Therefore, the loss of reflected light can be reduced, and the brightness of the display surface of the liquid crystal display device 1 can be improved. 15 The upper substrates 7b, 7g, 7r and the lower substrates 9b, 9g, and 9r must have light transmissivity. A two-piece polycarbonate (PC) film substrate cut into a length and length of 1 〇 (cm) X 8 (cm) was used. Further, a film substrate such as a glass substrate or polyethylene terephthalate (PET) may be used instead of the pc substrate. These film substrates have sufficient flexibility. In this embodiment, the substrates 7b, 7g, and 7r and the lower substrates 9b, 9g, and 9r are required to have light transmissivity. However, the substrate 9r under the R display portion 6r disposed at the lowermost layer may be opaque. As shown in Fig. 4 and Fig. 5, a plurality of strip-shaped data electrodes 19b extending in the upper and lower directions in Fig. 4 are formed side by side on the liquid crystal layer 3b side of the substrate Bb under the B display portion 6b. Further, reference numeral 19b in Fig. 5 indicates the existence region of the plurality of strip-shaped paste electrodes 19b. Further, on the liquid crystal layer 3b side of the upper substrate 71), scanning electrodes 17b of a plurality of strips 18200837427 extending in the left-right direction in Fig. 4 are formed in parallel. As shown in Fig. 4, the upper and lower substrates 7b and 9b are viewed in the normal direction of the electrode forming surface. The scanning electrode m and the data electrode are arranged in a direction opposite to each other. Ο·% leg spacing 5 strips of 240 scanning electrodes 17b and 32 strips of data electrodes jump to achieve a 240x320 point qVGA display. The fields in which the two electrodes m and the jumps intersect each constitute a B pixel i2b. The plurality of B pixels Ub are arranged in an array of 24 lines and 320 columns. The liquid crystal display element 6g for G is also formed in the same manner as the liquid crystal display element B for B. The data electrode 19g having 240 scanning electrodes 17g and 320 and the G pixel 12g arranged in an array of 24 rows and 320 rows (not shown) The display liquid crystal display element 6r is also similar to the scan electrode i7r, the data electrode 19r, and the r pixel 12r (not shown). The liquid crystal is composed of one set of B, G, and R pixels! 2b, 12g, and 12r. One pixel 12 of the display device 1. The pixels 12 are arranged in an array to form a display screen. The scanning electrodes 17b, 17g, 17r and the data electrodes 19b, 19g, and 19r are typically formed of indium tin oxide (indium). Tin Oxide; ITO), a transparent conductive film such as indium Zinc Oxide (IZO), a metal electrode such as aluminum or tantalum or a transparent conductive 20 film such as amorphous germanium can be used. The scan electrode drive circuit 25 of the scan electrode driver 1C for the wiper electrodes 17b, 17g, and 17r is connected to the upper substrates 7b, 7g, and 7r. Further, the data electrode driver 1C for driving the plurality of data electrodes 19b, 19g, and 19r is mounted. Data electrode driving circuit 27 is connected The lower substrate 19 200837427 9b 9g 9r° includes the scan electrode driving circuit 25 and the data electrode driving circuit 27 to constitute the driving portion 24. The sweep electrode driving circuit 25 is constructed in accordance with a predetermined signal output from the control circuit portion 23. The predetermined three scanning electrodes 17b, 17g, and 17r are selected, and the three scanning electrodes 17b, 17g, and 17r simultaneously output scanning signals. The data electrode driving circuit 27 is constructed in accordance with the control circuit portion 23. The predetermined signal is output, and the image data signals of the B, G, and R pixels 12b, l2g, and 12]« on the selected scanning electrodes H 17g, 17r are output to the data electrodes 19b, 19g, and I9r, respectively. For the electrode and the f-electrode 10, the IC can be used as an IC, for example, a conventional STN driver 1C having a structure of a tape-and-reel package. Since this embodiment can use various liquid crystals for B, G, and R. The driving voltages of 3g and 3r are set to be the same. Therefore, the predetermined output terminals of the scan electrode driving circuit 25 are commonly connected to the predetermined 15-input terminals of the scanning electrodes 17b, I7g, and nr. Thus, it is not necessary for each B. 'G, R for each liquid crystal Since the display elements 6b, 6g, and 6r are provided with the scan electrode driving circuit 25, the structure of the driving circuit of the liquid crystal display device 1 can be simplified. Further, since the number of the driving electrodes 1C for the female electrode can be eliminated, the liquid crystal display device can be realized. The cost of the crucible is 2. The two electrodes Pb and 19b are respectively coated with an insulating film and an alignment film for controlling the arrangement of the liquid crystal molecules (all of which are not shown) as a functional film. The insulating film has a function of preventing short-circuiting between the electrodes 17b, 19b or as a gas barrier layer to improve the reliability of the liquid crystal display device 1. Further, an organic film such as a polyethylideneamine resin, a polyamidene resin, a polymyimide resin, a polyvinyl chloroprene ruthenium 200837427 or an acrylate resin, or an iridium oxide or an aluminum oxide can be used. As an alignment film. This embodiment is, for example, an eight-sided substrate on the electrode and an alignment film. The alignment film may also use an insulating film. As shown in Fig. 5, the B liquid crystal 3b is sealed between the two substrates and the outside by the dense sealing material 21b applied around the upper and lower substrates 7b and %. Further, the thickness (= panel pitch) d of the liquid crystal 3b must be kept uniform. In order to maintain the predetermined panel pitch d, a spherical spacer made of resin or inorganic oxide is dispersed in the liquid crystal 3b for B, or a columnar spacer is formed in the liquid crystal 3b for 6 in most cases. In the liquid crystal display device of the present embodiment, a spacer (not shown) is inserted into the liquid crystal 10 3b for B to maintain the uniformity of the panel pitch 4. Further, a case where a wall structure having an adhesive property is formed around the pixel is also applicable. The panel spacing d is preferably in the range of 3 μ 6 //m. If the panel pitch d is smaller than this range, the reflectance of the liquid crystal 3b in the parallel spiral state becomes low, and if it is larger than this range, the driving voltage becomes too high. The embodiment of this embodiment is set to panel spacing = 4 #πι. The liquid crystal display element 6g for G and the liquid crystal display element 6r for R have the same structure as the panel pitch = 4 // m which is the same as the B liquid crystal display element 6b, and therefore the description thereof will be omitted. The outer surface (back surface) of the substrate 9r under the liquid crystal display element 6r for R is disposed on the visible light absorbing layer 15. Since the visible light absorbing layer 15 is provided, light reflected by the respective liquid crystals 3b, 3g, and 3r for B, G, and R can be efficiently absorbed. Here, the liquid crystal display device 1 can realize a contrast display. Further, the visible light absorbing layer 15 may be provided as necessary. The driving method of the liquid crystal display device 1 will be described below using Fig. 7 . Fig. 7 shows an example of a driving method of the liquid crystal display device 1. Fig. 7(a) is used for 21 200837427 to make the cholesterol m fresh spiral waveform, and the seventh guide is used to make the cholesteric liquid crystal into a vertical spiral state __. _7_ and 7_), the upper part of the figure shows the scanning signal voltage waveform VS outputted from the data signal output circuit 27 of the data electrode driving circuit 27, which is output from the sweeping electrode circuit 25, which is shown in the main _ Further, it is not applied to the liquid crystal for B, and the applied voltage waveform Vle of the pixel is shown from the left to the right of the figure. Also, in Figure 7 (8) and Figure 7 (8)

On the other hand, the upper and lower directions of the figure indicate electricity. Fig. 8 shows an example of the voltage-reflectance characteristics of the cholesteric liquid crystal. The horizontal axis represents the voltage value (v) applied to the cholesteric liquid crystal, and the vertical axis represents the reflectance (%) of the cholesterol liquid crystal. The curve p of the solid line shown in Fig. 8 indicates the voltage-reflectance characteristic of the cholesteric liquid crystal whose initial state is a parallel spiral state, and the curve FC of the broken line indicates the voltage-reflectance characteristic of the liquid crystal of the liquid crystal in the initial state of the vertical state. .

By way of example, a predetermined voltage is applied to the blue (B) pixel 12b (1, 1) at the intersection of the first data electrode 19b of the B liquid crystal display element 6b of the fourth picture and the Sweeping electrode #7. situation. As shown in FIG. 7 (^), during about 1/2 of the front side of the selection period T1 of the scanning electrode 17b of the first row, the scanning signal voltage % is 0 V with respect to the data signal voltage Vd of +32 V, and The scanning signal voltage Vs is +32 V with respect to the data signal voltage ~0 V for about 1/2 of the rear side. Therefore, B of the B pixel I2b (1, 1) is applied between the selection period D1. Pulse wave voltage of ±32v. As shown in Fig. 8, when a high voltage VP1〇〇 (for example, 32v) exceeding the HT voltage is applied to the cholesteric liquid crystal to generate a strong electric field, the liquid crystal molecule snail 22 200837427 When the liquid crystal molecules of the B pixels 12bU and 1) are vertically aligned with each other in the selection period T1, the liquid crystal molecules of the B liquid crystals 3b of the B pixels 12bU and 1) are completely aligned. When the selection period T1 ends and the non-selection period T2 is present, a voltage of, for example, +28 V or +4 V is applied to the scan electrode 17b of the first row with a period of 1/2 of 11 periods of the selection period. On the other hand, the data signal voltage of the shape is applied to the data electrode 19b of the first column. In Fig. 7 (8), voltages of, for example, +32 V and 0 V are applied to the data electrodes 19b of the first column in the non-selection period T2 after the completion of the selection period in the selection period Tk1/2. Therefore, the pulse voltage of the soil 4 ¥ can be applied to the liquid crystal 3b for the 8 pixels 12b (l, l) iB between the non-selection periods. As a result, between the non-selection period T2, the electric field generated by the B liquid crystal 3b of the B pixel U is approximately zero. When the liquid crystal molecules are vertically aligned, the applied liquid crystal voltage is changed from VP 100 (±32V) exceeding HT voltage to VF0 (±4 v), and the electric field is sharply set to about 15 k'. The two electrodes 17b, 19b assume a spiral state toward the approximately vertical direction, and form a parallel spiral state of light selectively reflecting the corresponding helical pitch. Thus, in order to cause the B liquid crystal 3b of the B pixel 12b (1, i) to form a parallel spiral state, the light is reflected, and the B pixel 12b (1, 1) displays blue. 20 In contrast, as shown in Fig. 7(b), during the selection period, the front side is about 1 /2 and the back side is about 1/2, and the signal voltage is once scanned with respect to the data signal voltage of 24V / 8V. When the vs is 0 V / + 32 V, the pulse voltage of ±24 V is applied to the liquid crystal 3b for B of the B pixel 12b (1, 1). As shown in Fig. 8, once a predetermined low voltage VF1 〇〇 b (e.g., 24 V) is applied to the liquid crystal of the cholesterol 23 200837427 to generate a weak electric field, the spiral structure of the liquid crystal molecules forms an incompletely unwrapped state. Once the non-selection period 12 is reached, a voltage of, for example, + 28 乂 / + 4v is applied to the scan electrode nb of the first row with a period of 1 1/2 of the selection period, and a predetermined tributary signal voltage of ¥ (1 (for example, +24 V/) The voltage of 8V) is applied to the data electrode 1% in a period of 5 1/2 of the extension period T1. Therefore, the pixel 12b can be used between the non-selection period T2 (1, the liquid crystal% is applied - 4v / + 4V pulse) In this case, the electric field generated by the liquid crystal 3b in the B pixel 12b (b1) is about zero between the non-selection periods 2, and the spiral structure of the liquid crystal molecules is not completely unwrapped. When the voltage applied to the cholesteric liquid crystal is changed from VF100b (±24V) to VF0 (±4V), the electric field is sharply changed to about zero, and the spiral axis of the liquid crystal molecules is oriented in a direction parallel to the two electrodes 17b and 19b. In the spiral state, the vertical spiral state of the incident light is transmitted. Therefore, the liquid crystal 3b of the B pixel 12b (1, 1} is vertically spirally transmitted to transmit light. Further, as shown in Fig. 8, 15 ν ρ 〇〇 is applied. After the voltage of (ν) causes a strong electric field to be generated in the liquid crystal layer, even if the electric field is gradually removed, the cholesterol is cooled. The liquid crystal can also form a vertical spiral state. The above-mentioned driving voltage and driving method are an example. When a pulse-like voltage of 30 to 35 V is applied between the electrodes at room temperature for an actual utility time of 2 〇 to 丨〇〇 ms, The liquid crystal liquid crystal of B is in a selectively reflective state (parallel spiral 20 state), and a practical transmission time between 2 〇 and 100 ms is applied between the pulse voltages of 15 to 22 V, and a good transmission state (vertical spiral state) is obtained. The green (G) pixels (1, 1) and (R) pixels (!, !) are driven in the same manner as the driving of the B pixels 12b (1, 1), so that three b, g, and three layers can be stacked. The R pixel (1, 1) performs color display. Further, the electrode from the 1st line to the magnetic line scan 24 200837427 is driven by so-called line sequential driving to rewrite each data electrode in each line (data scanning electrode) Thereby, the display data can be output to all of the pixels (Bu 1) to the pixels (m, η), and the color display of the frame (display screen) size can be realized. 5 Also, the two of the eighth figure The voltage in box A and Β is applied to the cholesteric liquid crystal to impart intermediate strength. When the electric field is sharply removed and the electric field is sharply removed, an intermediate state in which the parallel spiral state and the vertical spiral state are mixed is formed, and a full-color display can be formed. The following describes the manufacturing method of the liquid crystal display device of the present embodiment. (Example) An IT 〇 transparent electrode was formed by sputtering on a two-piece polycarbonate (PC) film substrate having a length of, for example, 1 〇 (cm) x g (cin). The etched electrode is patterned to form a strip-shaped electrode (scan electrode π or data electrode 19) at a pitch of 15 0. 24 ηηπι. A strip-shaped electrode is formed on each of the two PC film substrates to achieve a QVGA display capable of displaying & 240 points. Next, a polyimide film having a thickness of 7 Å was coated on the strip-shaped transparent electrode on each of the two PC film substrates by using an applicator. Twenty times, the two PC films which had been coated with the alignment film material were placed in an oven at 9 ° C for one hour to form an alignment film. Next, an epoxy-based sealing material was applied to the peripheral portion of the PC film substrate on one side by a feeder. Next, the panel door 25 200837427 (liquid crystal layer thickness) was adjusted to about 4 / / m on the other side of the PC film substrate 9 or 7 spacer spacer (manufactured by Sekisui Precision Chemicals Co., Ltd.). Next, the two PC film substrates 7 and 9 were bonded together, and the sealing material 21 was cured by i6 (rc heating) for an hour. Further, the B liquid crystal LCb for B was injected by a vacuum injection method, and then filled with an epoxy resin. The sealing material is filled to fill the injection port to form a liquid crystal display element for B. The liquid crystal display elements for G and R are formed by the same method, and 6r is used. The liquid crystal to be implanted is used for selectively reflecting a predetermined wavelength of light. The dielectric anisotropy of the liquid crystal material of the indexing element is larger than the dielectric anisotropy of the liquid crystal material of the display element which selectively reflects a predetermined wavelength. For example, Δειι=9.5, ΔεΒ=21 1 In the state of the crucible, the driving voltage and the panel pitch of the plurality of panels can be improved, and the manufacturability and cost can be improved. Next, as shown in FIG. 5, the liquid crystal display elements for B, G, and R are displayed from the display surface side. The layers of 6b, 6g, and 6r are laminated in sequence. Then, the pure crystal display element & Μ 基板 基板 % % % % % % % 配置 配置 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光 可见光On the accumulated layer =, G The liquid crystal display elements 6b, 6g, & the terminal portion of the scan electrode 17 and the terminal portion of the data electrode 19 are connected to the power supply circuit and the control circuit portion. Thus, the turtle can be used to perform the QVG surface display and the crystal device. According to the embodiment, the panel pitch of the plurality of liquid crystal display elements of the different wavelengths of light selectively reflected can be aligned to be about the same. Therefore, the manufacturing process of the liquid crystal display element to fill the liquid crystal project can be The same work can be used depending on the liquid crystal material used for the color of the seal. For example, in the liquid crystal filling by the true injection method, the empty panel before the liquid crystal injection can be manufactured by the same engineering. However, it is therefore more convenient to manufacture the three kinds of empty panels of different pitches than the need to prepare 26 200837427, and the manufacturing cost can be reduced.

Different, so the scanning electrodes can be combined for a plurality of liquid crystal display elements. Therefore than for a plurality of liquid crystal display elements in each liquid

It is necessary to provide a conventional manufacturing process of the scanning electrode driving circuit, which is easy to manufacture and can be manufactured at a low cost. The liquid crystal display device 1 of the company has completed the input of the input wheel-out device and the control device of the overall control unit (all not shown in the figure) to complete the paper. Fig. 9 shows a specific example of the electronic paper EP having the liquid crystal display having the present embodiment. Fig. 9(a) shows an electronic paper 15 EP having a structure in which a non-electric memory lm having pre-stored image data is inserted and removed in the liquid crystal display device 1 constructed by the bear according to the present embodiment. . For example, image data stored in a personal computer or the like is stored in the non-electric memory lm, and is mounted on the electronic paper Ep to display an image. Fig. 9(b) shows an electronic paper EP having a structure in which a non-electrical memory lm is built in the liquid crystal display device 1 constructed in accordance with the present embodiment. For example, the non-electrical memory lm can store image data and display the image by wire from the terminal lt (which can constitute one part of the electronic paper EP) in which the image data is stored. Fig. 9(c) shows an example in which the terminal It and the liquid crystal display device 1 have a wireless transmission receiving system (e.g., wireless LAN or Bluetooth). The wireless communication lwl can store the image data from the terminal which stores the image data, and the image display can be performed after the non-electric memory lm is stored. Hereinafter, the advantages of the liquid crystal display device constructed in accordance with the present embodiment will be specifically described using a comparative example. (Comparative Example 1) 5 Three empty panels having a panel pitch of about 4 μm were produced in the same manner as in the above embodiment. Three types of liquid crystals for red, green, and blue in which the dielectric anisotropy Δ ε is approximately equal are prepared. More specifically, Δ eR = 15.9, Δ eG = 15.3, and Δ ε Β = 14.7. A liquid crystal display element was produced by injecting three empty panels into each of the liquid crystals for each color. When the driving voltage (ΗΤ voltage) of the liquid crystal is measured, the liquid crystal display element of the red color is about 19 V, the green liquid crystal display element is about 25 V, and the blue liquid crystal display element is about 31. The configuration of the first comparative example requires that the driving circuit be separately provided for each color, and thus the reduction of the present embodiment cannot be achieved. (Comparative Example 2) 15 Three types of liquid crystals of red, green, and blue for dielectric anisotropy Δ ε R = 15.9, Δ £ (} = 15.3, and £8 = 14.7 were prepared in the same manner as in the above comparative example. When the driving voltage of the liquid crystal is set to be, for example, about 31 V, the panel pitch of the red, green, and blue empty panels must be changed to about 6.5 μm, about 5 #m, and about 4 // m, respectively. The structure must be manufactured by a conventionally complicated manufacturing process, and thus the ease of manufacture as in the present embodiment and the manufacturing cost can be reduced. Industrial Applicability The present invention is not limited to the above embodiment, and In the above embodiment, the liquid crystal display device of the dot matrix type is exemplified by 28 200837427. However, the present invention is not limited thereto, and the liquid crystal display device of the segment type may of course be applicable. The above embodiment is described by taking a liquid crystal display device having a three-layer structure of B, G, and ruler liquid crystal display elements 6b, 6g, and 6r as an example. However, the present invention is not limited thereto, and the second or fourth layer is not limited thereto. The above liquid crystal display device having a laminated structure can also be applied.

Further, although the scanning electrode driving circuit is common to the above-described embodiment, the driving circuit may be commonly used as necessary. Of course, the plurality of panels may each have a scanning electrode driving circuit. Moreover, the above-described embodiment exemplifies a liquid crystal display device having liquid crystal display elements 6b, 6g, and 6g, and the liquid crystal display element 讣, 6g, "having a liquid crystal display that reflects blue, green, or red light in a parallel spiral state. The elements 3b, 3g, and 3r are described as an example. However, the present invention is not limited thereto, and a liquid crystal display in which a plurality of liquid crystal display elements which reflect liquid crystals of cyanine, magenta, and yellow light in a parallel spiral state is laminated is laminated. The apparatus can also be applied. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a cross-sectional structure of a liquid which is formed according to a third embodiment of the present invention. Fig. 2(a), (b) A schematic diagram showing a cross-sectional structure of a liquid crystal display device which is one of liquid crystal display devices according to a second embodiment of the present invention. Fig. 3 is a view showing a liquid crystal display device constructed in accordance with a first embodiment of the present invention. Fig. 4 is a view showing a schematic configuration of a liquid crystal display device according to a second embodiment of the present invention. A cross-sectional structure of a liquid crystal display device comprising a second embodiment of the present invention. Fig. 6 is a view showing an example of a reflection spectrum of a parallel spiral state of a liquid crystal display device constructed in accordance with a second embodiment of the present invention. (a) and (b) show a method of driving a liquid crystal display device according to a second embodiment of the present invention. Fig. 8 is a view showing an example of voltage-reflectance characteristics of a cholesteric liquid crystal. Fig. 9(a)~( c) shows a specific example of the electronic paper EP having the liquid crystal display device 1 constructed in the second embodiment of the present invention. 10 [Description of main component symbols] 1. 5l···Liquid crystal display device U·.·Pixel 3b , 43b... blue (B) liquid crystal 12b... blue (B) pixel 3g, 43g··· green (G) liquid crystal 12&" green (〇) pixel 31-431-red (11) liquid crystal...red (R) pixels 6b, 46b... blue (B) liquid crystal display elements b, 45··· visible light absorbing layer members 17r, 17g, 17b···scan electrodes 6g, 46g... green (G) liquid crystal display element 19r , 19g, 19b... data electrode parts 21, 21b, 21g. " sealing material 6r, 46r · · · red (R) with liquid crystal display Display elements 23···control circuits 7b, 7g, 7r, 47b, 47g, 47r···Upper 24...Drive unit 25...Scan electrode drive circuits 9b, 9g, 9r, 49b, 49g, 49r··27... Electrode driving circuit wire 33...liquid crystal molecule 30 200837427 41b, 41g, 41r···pulse wave voltage source EP...electronic paper

31

Claims (1)

200837427 10 15 20 X. Patent application scope: • A liquid crystal display device having a plurality of liquid crystal display elements stacked thereon, and the plurality of liquid crystal display elements selectively multiplying light of different wavelengths in the opposite base (four) filling village Further, 'the dielectric anisotropy of the liquid crystal selectively reflecting light having a relatively short wavelength is larger than the dielectric anisotropy of the liquid crystal selectively reflecting light having a relatively long wavelength. 2. The liquid crystal display device of claim 1, wherein the plurality of liquid crystal display elements have a panel pitch of about the same. 3. The liquid crystal display device of claim 1, wherein the driving voltage range of the plurality of liquid crystals is about the same. 4. The liquid crystal display device according to any one of claims 1 to 3, wherein the plurality of liquid crystals comprise liquid crystals forming a cholesterol phase. 5. The liquid crystal display device of claim 4, further comprising: a blue liquid crystal display element which is filled with blue liquid selectively reflecting blue light between the opposite substrates; a green liquid crystal display element in which a green light is reflected by green liquid crystal and sealed between the opposite substrates; and a red liquid crystal display element in which red liquid is selectively reflected by the liquid crystal is sealed between the opposite substrates. Further, the dielectric anisotropy of the blue liquid crystal is Δ ε b , the dielectric anisotropy of the green liquid crystal is Δ ε g , and the dielectric anisotropy of the red liquid crystal is used. When Δ eR is set, the relationship of Α ε Β > Δ £r > is satisfied. The liquid crystal display device of claim 5, wherein the blue liquid crystal display element, the green liquid crystal display element, and the red liquid crystal display element are laminated in this order from the display surface side. 7. The liquid crystal display device of claim 6, wherein the optical property of the green liquid crystal 5 is different from the optical power of the blue liquid crystal and the red liquid crystal. 8. A type of electronic paper for displaying an image, comprising: a liquid crystal display device according to any one of claims 1 to 7. 10 33