JP2013142753A - Electrowetting display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrowetting display capable of displaying a stereoscopic image without special spectacles, and achieving thinness and downsizing.SOLUTION: The present invention relates to an electrowetting display in which each of a pair of substrates configuring one cell has a driving unit. The electrowetting display is configured by bonding a first substrate accommodating a first hydrophobic liquid material in a region surrounded by a first pixel wall and a second substrate accommodating a second hydrophobic liquid material in a region surrounded by a second pixel wall, via a hydrophilic material. In a first substrate side, a voltage is applied to the first hydrophobic liquid material to change a shape of an interface between the first hydrophobic liquid material and the hydrophilic material, and thereby the first substrate is caused to function as a lens. Also, in a second substrate side, the voltage is applied to the second hydrophobic liquid material to change the shape of the interface between the second hydrophobic liquid material and the hydrophilic material, and thereby the second substrate is caused to function as a shutter permitting light via a color filter layer to pass through to the first substrate side.

Description

  The present invention relates to an electrowetting display.

  In recent years, an electrowetting device using an electrowetting effect has attracted attention. In general, an electrowetting device is composed of a pair of substrates filled with a hydrophilic (high surface energy) liquid and a hydrophobic (low surface energy) liquid, and at least one substrate has an electrode layer on the surface. And a hydrophobic intermediate layer (insulating layer) formed on the surface of the electrode layer (see, for example, Patent Document 1). In the electrowetting device, when a voltage is applied between the hydrophilic liquid and the electrode layer via the hydrophobic intermediate layer, the hydrophilic liquid is attracted to the hydrophobic intermediate layer, and the hydrophilic liquid and the hydrophobic liquid are separated. It has the characteristic that the interface shape between changes. An electrowetting device is used for an optical lens, a display element, etc. using such characteristics.

  By the way, in recent years, as a device for displaying stereoscopic images without using special glasses, it is possible to separate light from right-eye images and left-eye images using a parallax barrier or lenticular lens. A technique is known that enables a viewer to view a stereoscopic image.

International Publication No. WO05 / 098797

  Therefore, it is desired to provide a new technique capable of displaying a stereoscopic image by using the above-described electrowetting device. However, a display device that can display a stereoscopic image without glasses has a problem that it is difficult to reduce the thickness or size of the display device because it is necessary to provide the above-described parallax barrier and lenticular lens on the display surface side. .

  An object of the present invention is to provide an electrowetting display capable of displaying a stereoscopic image without using special glasses and realizing a reduction in thickness and size.

  The electrowetting display according to the first aspect of the present invention is an electrowetting display in which each of a pair of substrates constituting one cell has a drive unit, and is in a region surrounded by a first pixel wall. The first substrate storing the first hydrophobic liquid material and the second substrate storing the second hydrophobic liquid material in the region surrounded by the second pixel wall are interposed via the hydrophilic material. At the first substrate side, a voltage is applied to the first hydrophobic liquid material to change the interface shape between the first hydrophobic liquid material and the hydrophilic material. Thus, on the second substrate side, a voltage is applied to the second hydrophobic liquid material to form an interface shape between the second hydrophobic liquid material and the hydrophilic material. By changing the color Characterized in that the functioning of the light through the data layer as a shutter which transmits on the first substrate side.

  According to the electrowetting display of the present invention, on the first substrate side, the interface shape between the first hydrophobic liquid material and the hydrophilic material can be changed to function as, for example, a lenticular lens. It is possible to make the viewer visually recognize the stereoscopic image. In addition, since the first substrate and the second substrate are attached to each other through a common hydrophilic material, the size and thickness can be reduced.

  The electrowetting display according to the second aspect of the present invention is an electrowetting display in which each of a pair of substrates constituting one cell has a drive unit, and is in a region surrounded by the first pixel wall. The first substrate storing the first hydrophobic liquid material and the second substrate storing the second hydrophobic liquid material in the region surrounded by the second pixel wall are interposed via the hydrophilic material. At the first substrate side, a voltage is applied to the first hydrophobic liquid material to change the interface shape between the first hydrophobic liquid material and the hydrophilic material. Thus, on the second substrate side, a voltage is applied to the second hydrophobic liquid material to form an interface shape between the second hydrophobic liquid material and the hydrophilic material. By changing the color Characterized in that the functioning of the light through the filter layer as a shutter which transmits on the first substrate side.

  According to the electrowetting display of the present invention, on the first substrate side, the interface shape between the first hydrophobic liquid material and the hydrophilic material can be changed to function as a parallax barrier (parallax barrier). Therefore, it is possible to make an observer visually recognize a full-color stereoscopic image. In addition, since the first substrate and the second substrate are attached to each other through a common hydrophilic material, the size and thickness can be reduced.

In the electrowetting display, a hydrophobic liquid material having a light shielding property may be stored as the first hydrophobic liquid material in each of the regions surrounded by the first pixel walls. Good.
According to this configuration, the light of various colors in the region surrounded by the second pixel wall on the second substrate side can be selectively incident on the right eye and the left eye of the observer, and the stereoscopic image can be displayed. It can be visually recognized well.

In the electrowetting display, the hydrophilic material may be a gel substance.
According to this configuration, since the hydrophilic material is composed of a gel substance, it is possible to apply the hydrophilic material to at least one of the first substrate and the second substrate and bond the two substrates. Therefore, the manufacturing process of the electrowetting display can be simplified and the cost can be reduced.

Further, in the electrowetting display, the height of at least one of the first pixel wall and the second pixel wall is the height of the hydrophobic liquid material stored therein in a voltage non-application state. It may be set to 2 to 20 times.
According to this configuration, since the height of the pixel wall is set within a predetermined range, the hydrophobic liquid material can be favorably moved.

In the electrowetting display, the surface on the side having the pixel wall and the pixel wall in at least one of the first substrate and the second substrate may be hydrophobic.
According to this configuration, since the pixel wall as well as the surface on the side having the pixel wall can be made hydrophobic, the hydrophobic liquid material can be more uniformly stored in the region surrounded by the pixel wall. .

  According to the present invention, a stereoscopic image can be displayed without using special glasses while realizing a reduction in thickness and size.

Schematic which shows the cross-sectional structure of the electrowetting display which concerns on 1st Embodiment. Sectional drawing which shows the principal part structure of the electrowetting display which concerns on 1st Embodiment. The figure for demonstrating the operation | movement concept of the electrowetting display which concerns on 1st Embodiment. The figure for demonstrating the operation | movement concept of the electrowetting display which concerns on 1st Embodiment. The conceptual diagram for demonstrating the structure which concerns on the modification of the 1st board | substrate by the electrowetting display which concerns on 1st Embodiment. The conceptual diagram for demonstrating the stereoscopic image display by the electrowetting display which concerns on 1st Embodiment. Schematic which shows the cross-sectional structure of the electrowetting display which concerns on 2nd Embodiment. The figure for demonstrating the operation | movement concept of the electrowetting display which concerns on 2nd Embodiment. The conceptual diagram for demonstrating the stereo image display by the electrowetting display which concerns on 2nd Embodiment. The conceptual diagram for demonstrating the relationship between the applied voltage to the pixel electrode and barrier opening in the electrowetting display which concerns on 2nd Embodiment. The figure for demonstrating the change of the magnitude | size of the barrier opening which concerns on 2nd Embodiment. Schematic which shows the cross-sectional structure of the electrowetting display which concerns on 3rd Embodiment. The schematic diagram showing the plane composition of the 1st substrate concerning a 3rd embodiment. The schematic diagram showing the plane composition of the 1st substrate concerning a 3rd embodiment. The conceptual diagram for demonstrating the stereo image display by the electrowetting display which concerns on 3rd Embodiment. Schematic which shows the planar structure of the 1st board | substrate which concerns on the modification of this invention.

  Hereinafter, embodiments according to the electrowetting display of the present invention will be described.

(First embodiment)
Hereinafter, embodiments of the electrowetting display of the present invention will be described with reference to the drawings. The electrowetting display according to the present embodiment has a pair of substrates each having an electrowetting device formed thereon, and allows one substrate side to function as an image display unit that displays an image for the right eye and an image for the left eye. By making the other substrate side function as a lenticular lens, the right eye image and the left eye image are optimally viewed by the observer's right eye and left eye, respectively, and a stereoscopic image can be obtained without using special glasses. It is a display that is visible.

FIG. 1 is a schematic view showing a cross-sectional configuration of the electrowetting display according to the first embodiment.
As shown in FIG. 1, the electrowetting display 100 according to the present embodiment includes a first substrate 110 and a second substrate 120, and these substrates 110 and 120 are arranged to face each other with a hydrophilic material 130 interposed therebetween. ing. The hydrophilic material 130 is disposed in a region defined by a seal member 140 provided along the outer periphery of the substrates 110 and 120. In the present specification, the “cell” means a region where the hydrophilic material 130 and the hydrophobic liquid materials 131 and 132 described later are disposed between the first substrate 110 and the second substrate 120. The sealing member 140 has an inter-substrate conducting portion 140a embedded therein that conducts between the first substrate 110 and the second substrate 120. The position where the inter-substrate conducting portion 140a is provided is not limited to the inside of the seal member 140, and may be provided outside or inside the seal member 140.

  FIG. 2 is a cross-sectional view showing a main configuration of the electrowetting display. 3 and 4 are diagrams for explaining the operation concept of the electrowetting display. In each figure, the drawings are simplified for members that are not necessary for the description.

  As shown in FIG. 2, the first substrate 110 includes a base material 110 </ b> A, a solid pixel electrode 114, and an insulating film 116. The pixel electrode 114 is formed on the base material 110 </ b> A and is covered with an insulating film 116. The pixel electrode 114 is connected to an external device (power source) in a region not shown. The solid shape means that one common transparent electrode is formed in all the pixels G1.

  110 A of said base materials are comprised from what is normally used as a panel substrate of a display apparatus, such as glass, a resin molding, and a film, for example. In this embodiment, for example, glass is used. A conductive portion 118 that is partially pulled out of the seal member 140 is formed at the end of the base material 110A. The conductive portion 118 is electrically connected to the second substrate 120 side via an inter-substrate conductive portion 140a provided in the seal member 140. The conductive portion 118 is in contact with the hydrophilic material 130 and has the same potential.

  A first pixel wall 117 is formed on the insulating film 116 of the first substrate 110. A hydrophobic intermediate layer 128 is provided so as to cover the surfaces of the first pixel wall 117 and the insulating film 116. The first pixel wall 117 is formed in a stripe shape and partitions a plurality of regions on the first substrate 110. A hydrophobic liquid material (first hydrophobic liquid material) 131 is stored in an area partitioned by the first pixel wall 117 (hereinafter also referred to as a pixel G1). The first pixel wall 117 is formed using a photoresist (for example, SU-8 (manufactured by Microchem)) and has a height of 40 μm. The pixel electrode 114 is made of, for example, ITO, IZO, conductive polymer, conductive nanowire, or the like.

  The hydrophobic liquid material 131 is not particularly limited as long as it has optical transparency, and examples thereof include alkanes such as decane, undecane, dodecane, and hexadecane, silicone oil, and fluorocarbon. In addition, these materials may be used independently and may use 2 or more types together. In this embodiment, decane (refractive index: 1.411) was used.

  The hydrophobic liquid material 131 is disposed in the pixel G1 with a thickness of 5 μm using, for example, an inkjet device. That is, in the present embodiment, the height of the pixel wall 117, which will be described in detail later, is set to 8 times the height in a voltage non-applied state. Note that the arrangement method of the hydrophobic liquid material 131 is not particularly limited, and for example, screen printing, flexographic printing, gravure printing, dispensing, or the like can be used in addition to the inkjet method. If these methods are used, the hydrophobic liquid material 131 can be satisfactorily stored in regions surrounded by different pixel walls 117.

  On the other hand, as shown in FIG. 2, the second substrate 120 includes a base material 120A, a color filter layer 30, a TFT (driving unit) 121, a pixel electrode 124, a common electrode 125, a first insulating film 126a, and a second insulating film. 126b. 120 A of said base materials are comprised from what is normally used as a panel substrate of a display apparatus, such as glass, a resin molding, and a film, for example. In this embodiment, for example, glass is used.

  The TFT 121 and the pixel electrode 124 are electrically connected through a contact hole provided in a region not shown. The color filter layer 30 is sandwiched between the second insulating film 126b and the first insulating film 126a. The color filter layer 30 includes, for example, filter units 30R, 30G, and 30B corresponding to RGB (Red, Green, and Blue), a black matrix BM that is provided in each filter unit 30R, 30G, and 30B and functions as a light shielding film, Is included. The TFT 121 is disposed in the second insulating film 126b in a region overlapping a black matrix BM of the color filter layer 30 described later in a plan view.

  The filter portion of the color filter layer 30 is not limited to the above RGB, and is compatible with CMY (Cyan, Magenta, Yellow) or four types (for example, RGGB (Red, Green, Green, Blue)). Or RGBY (Red, Green, Blue, Yellow) can be employed.

  As shown in FIG. 1, a conductive portion 119 is formed on the end portion of the base member 120 </ b> A. The conductive portion 119 is partially drawn out of the seal member 140. The conductive portion 119 is in contact with the hydrophilic material 130 and has the same potential. The conductive portion 119 is externally connected to the common electrode 125 provided on the second substrate 120, and each is grounded. In addition, the conductive portion 119 is electrically connected to the conductive portion 118 on the first substrate 110 side via an inter-substrate conductive portion 140 a provided in the seal member 140. Accordingly, the hydrophilic material 130 on the first substrate 110 side is set to the same potential (grounded state) as the hydrophilic material 130 on the second substrate 120 side and the common electrode 125 via the conductive portion 119. Therefore, the potential distribution in the thickness direction of the hydrophilic material 130 can be reduced. In addition, it is desirable that a plurality of the inter-substrate conductive portions 140a and the conductive portions 118 and 119 are provided in the cell. In this way, the variation in potential of the hydrophilic material 130 in the cell can be further reduced.

  A second pixel wall 127 is formed on the second insulating film 126 b of the second substrate 110. The second pixel wall 127 is formed in a lattice shape and partitions a plurality of pixels G2 on the second substrate 120. The second pixel wall 127 is formed so as to separate each of the filter portions 30R, 30G, and 30B constituting the color filter layer 30 into two. As a result, the second pixel wall 127 observes the right-eye image R and the left-eye image L by separating the light that has passed through the filter units 30R, 30G, and 30B into two as will be described in detail later. It is possible to make it visible to a person.

  A pair of pixel electrode 124 and common electrode 125 are arranged in each pixel G2. A hydrophobic liquid material (second hydrophobic liquid material) 132 is stored in a region (pixel G2) partitioned by the second pixel wall 127. The second pixel wall 127 is formed using a photoresist (for example, SU-8 (manufactured by Microchem)) and has a height of 40 μm. The pixel electrode 124 and the common electrode 125 are made of, for example, ITO, IZO, conductive polymer, conductive nanowire, or the like.

  The hydrophobic liquid material 132 is not particularly limited as long as it is a hydrophobic liquid having a light shielding property. For example, the hydrophobic liquid material 132 is colored with a dye and / or pigment that does not allow visible light to pass through the hydrophobic solvent. Using. The hydrophobic solvent is not particularly limited, and examples thereof include alkanes such as decane, undecane, dodecane, and hexadecane, silicone oil, and fluorocarbon. These hydrophobic solvents may be used alone or in combination of two or more. The dye or the pigment is not particularly limited. For example, various pigments and dyes such as inorganic, phthalocyanine, and azo organics can be used, but as a solution characteristic used for electrowetting, a hydrophobic liquid However, it is necessary not to dissolve in a hydrophilic liquid, and the pigment surface is appropriately subjected to hydrophobic treatment. For example, there are metal oxides such as iron and chromium, and sulfides. There are also reductants such as titanium oxide and carbons such as ketjen black. Metal complexes such as iron are also used.

  In this embodiment, a hydrophobic pigment mixture in which carbon black having a hydrophobic surface is dissolved in hexadecane at a concentration of 5 wt% is used as the hydrophobic liquid material 132.

  The hydrophobic liquid material 132 is disposed with a thickness of 5 μm in a region partitioned by the second pixel wall 127 using, for example, an inkjet device. That is, in the present embodiment, the height of the pixel wall 127, which will be described in detail later, is set to 8 times the height in a voltage non-applied state. Note that the arrangement method of the hydrophobic liquid material 132 is not particularly limited, and for example, screen printing, flexographic printing, gravure printing, dispensing, or the like can be used in addition to the inkjet method. If these methods are used, the hydrophobic liquid material 132 can be satisfactorily stored in regions surrounded by different pixel walls 127.

  In the present embodiment, a hydrophilic gel-like substance is used as the hydrophilic material 130. Specifically, a polyvinyl alcohol aqueous solution in which polyvinyl alcohol (“K120” manufactured by Kuraray Co., Ltd.) was dissolved in water so as to be 2 w% was used as a hydrophilic gel-like substance.

  The gel substance constituting the hydrophilic material 130 is a substance obtained by gelling a hydrophilic liquid. The gel substance is preferably an elastic gel. The hydrophilic liquid is not particularly limited. For example, a nonionic and highly polar liquid is preferable. Specifically, water, monovalent or low molecular weight such as methyl alcohol, ethyl alcohol, ethylene glycol, glycerin, or the like. A polyhydric alcohol etc. are mentioned. These hydrophilic liquids may be used alone or in combination of two or more. In this embodiment, glycerin (refractive index: 1.449) was used.

  In the present specification, the “gel” refers to a hydrophilic layer (hydrophilic material 130) and a hydrophobic layer (hydrophobic liquid materials 131 and 132) when a voltage is applied as an electrowetting display. A state of having a moderate flexibility that does not hinder the change in the interface shape between the two, and a hardness that does not fall even when facing down, for example, when the two substrates 110 and 120 are bonded together during the manufacturing process. means. More specifically, when the hydrophilic material 130 is formed by coating, when the coated surface is turned down and then the coated surface is turned up again, the thickness of the hydrophilic layer is reversed and returned. It is required to have almost the same thickness before and after. It is preferable that the thickness distribution before and after the reversing and returning operations is also substantially the same. Specifically, the average coating thickness Tave of the hydrophilic material 130 after the reversing and returning operations is preferably 90% or more of the thickness before the operations. Further, when the maximum application thickness Tmax and the minimum thickness Tmin are set, it is preferable that (Tmax−Tmin) / Tave <0.1.

  Examples of the method of gelling the hydrophilic liquid include, for example, a method of adding a gelling agent to the hydrophilic liquid, a method of lowering the temperature of the hydrophilic liquid, and a method combining these methods. Is mentioned.

  As the gelling agent, a hydrophilic polymer, an inorganic gelling agent, a low molecular gelling agent, or the like is used. Specific examples of the hydrophilic polymer include synthetic polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyhydroxyethyl methacrylate, starch, pectin, agarose, mannan, glycogen, carrageenan, cellulose, carboxycellulose, and the like. Modified cellulose, high-molecular polysaccharides such as hyaluronic acid, chitin, and chitosan, and low-molecular oligomer sugars thereof. Moreover, protein, a polypeptide, a polyamine, a glycoprotein, etc. are mentioned. Specific examples of the inorganic gelling agent include inorganic oxides such as silicon dioxide and titanium dioxide, inorganic hydroxides such as aluminum hydroxide, and the like. Examples of the low molecular gelling agent include surfactants having a long chain alkyl.

  In the electrowetting display 100, the amount of the gelling agent is such that a voltage is applied between the pixel electrode 124 and the common electrode 125 when a voltage is applied to the pixel electrode 114 on the first substrate 110 side or on the second substrate 120 side. When applied, the hydrophobic liquid materials 131 and 132 are appropriately adjusted so as not to prevent the hydrophobic liquid materials 131 and 132 from moving in the regions partitioned by the pixel walls 117 and 127. For example, when using polyvinyl alcohol, the upper limit with the preferable compounding quantity is 10 weight%.

  The hydrophilic material 130 may be a substance that is in a gel state even at room temperature by adding a gelling agent to a hydrophilic liquid, or by lowering the temperature when the electrowetting display 100 is manufactured. It may be gelled and returned to liquid form at room temperature after production. Even if the gelled material is used, the thickness does not change greatly even if it is turned upside down. Therefore, the first substrate 110 is turned upside down and the first substrate is interposed via the seal member 140. 110 and the second substrate 120 can be bonded together satisfactorily.

  The gel-like hydrophilic material 130 is applied to one surface of the transparent film surface, the hydrophilic material 130 of the film is bonded to the first pixel wall 117 side of the first substrate 110, and the other surface of the film is hydrophilic. The first substrate 110 and the second substrate 120 may be bonded together by applying the conductive material 130 and bonding the same to the second pixel wall 127 side of the second substrate 120.

  Moreover, the electrowetting display 100 can also be manufactured by bonding the first substrate 110 and the second substrate 120 each having the hydrophilic material 130 applied thereto.

The bonding of the first substrate 110 and the second substrate 120 is performed as follows, for example.
First, the hydrophilic material 130 made of a gel-like substance is applied on one surface of the base 110A of the first substrate 110, for example, using a knife coater so as to have a coating thickness of 100 μm. At this time, the hydrophobic liquid material 131 is stored in advance in a region partitioned by the first pixel wall 117 of the first substrate 110.

  And on the 1st board | substrate 110 which apply | coated the said hydrophilic material 130, photocurable A785 (made by Sekisui Chemical Co., Ltd.) is apply | coated with a dispenser so that a frame may be drawn as the said sealing member 140, and a seal pattern is formed. Is done.

  The first substrate 110 in which the hydrophilic material 130 (hydrophilic gel-like substance) is applied to the second substrate 120 in which the hydrophobic liquid material 132 is stored in each pixel G2 is bonded through the seal member 140 in the atmosphere, For example, the electrowetting display 100 can be manufactured by irradiating light of 1000 mJ with an ultra-high pressure mercury lamp having a center wavelength of 365 nm to cure the seal member 140.

  Since the hydrophilic material 130 disposed on the first substrate 110 does not fall even when placed on the lower side, the first substrate 110 and the second substrate 120 can be easily bonded together using a roll-to-roll method. Note that the hydrophobic liquid material 131 stored in the region partitioned by the first pixel wall 117 of the first substrate 110 is covered with the hydrophilic material 130 made of a gel-like substance. It is well held when facing down.

  In addition, the method of arrange | positioning the hydrophilic material 130 on the single side | surface of the 1st board | substrate 110 is not limited to the above-mentioned method, For example, you may use the method etc. which apply | coat using a roll coater, a die coater, etc. Further, as the hydrophilic material 130, a material that gels at the time of coating or after coating at the first substrate 110 or a fluid (sol) containing a hydrophilic liquid and a gelling agent may be used. Good.

  In addition, the process of disposing the hydrophilic material 130 on one surface of the first substrate 110 and the process of applying the hydrophobic liquid material 132 in the pixel G2 surrounded by the pixel wall 127 of the second substrate 120 are preceded. Or may be performed in parallel.

  The present inventors can manufacture the electrowetting display 100 having excellent responsiveness by making all the regions surrounded by the pixel walls 117 and 127 storing the hydrophobic liquid materials 131 and 132 hydrophobic. I found.

  That is, when the pixel walls 117 and 127 are hydrophilic, the wettability between the hydrophilic material 130 and the pixel walls 117 and 127 is high, and the wettability between the hydrophobic liquid material 131 and 132 and the pixel walls 117 and 127 is low. Therefore, the energy of the interface change from the hydrophilic material 130 to the hydrophobic liquid materials 131 and 132 on the surface of the pixel walls 117 and 127 is increased, and as a result, unevenness occurs when voltage is applied.

  Therefore, in the present embodiment, as shown in FIG. 2, the surface of the first substrate 110 on the side having the first pixel wall 117, the pixel wall 117, and the second pixel wall 127 of the second substrate 120 are provided. The surface and the pixel wall 127 are provided with hydrophobicity. As a method for imparting hydrophobicity, for example, the hydrophobic intermediate layer 128 is formed by applying a coating agent. The coating agent used for forming the hydrophobic intermediate layer 128 is not particularly limited. For example, fluorocarbons such as Teflon (registered trademark), ETFE (ethylene-tetrafluoroethylene copolymer), PVDF (polyvinylidene fluoride), and polypropylene are used. The thing which consists of a polymer and an alkyl polymer is mentioned. In the present embodiment, the hydrophobic intermediate layer 128 is coated on the entire surface of the pixel wall 127 and the second substrate 120 by a spin coat method using a Teflon (registered trademark) solution: AF1600 (manufactured by DuPont). Further, instead of providing the hydrophobic intermediate layer 128, the pixel wall 127 may be formed using a dry photoresist, an acrylic photoresist, or the like.

  As described above, according to the present embodiment, the hydrophobic intermediate layer 128 makes the surface of the second substrate 120 constituting the pixel wall 127 and the pixel G2 hydrophobic, so that the hydrophobic liquid disposed in each pixel G2 It is possible to prevent the material 132 from varying and to move the material 132 favorably.

  In addition, the present inventors set the height of the second pixel wall 127 to be higher than the maximum height of the hydrophobic liquid material 132 when a voltage is applied, so that the hydrophobic liquid material 132 is set. It was found that contamination due to can be suppressed. That is, it was found that the height of the pixel wall 127 is more preferably set to 2 to 20 times the height (thickness) of the hydrophobic liquid material 132 in a voltage non-applied state. In this description, the hydrophobic liquid material 132 on the second substrate 120 side will be described as an example. However, the height of the pixel wall 117 in the hydrophobic liquid material 131 on the first substrate 110 side is also set in a voltage non-applied state. It is desirable to set to 2 to 20 times the height (thickness) of the hydrophobic liquid material 131.

More specifically, the preferable lower limit is 2 to 5 times the height of the hydrophobic liquid material 132 in a state where no voltage is applied, and the preferable upper limit is the height of the hydrophobic liquid material 132 in a state where no voltage is applied. It is 8-20 times. If the height of the pixel wall 127 is less than twice the height of the hydrophobic liquid material 132 in a state where no voltage is applied, the hydrophobic liquid material 132 may gather on the pixel wall 127 when a voltage is applied. It cannot be made, and the inside of the pixel G2 cannot be made transparent. Further, sometimes the hydrophobic liquid material 132 gets over the pixel wall 127, and the hydrophobic liquid material 132 flows into the surrounding pixel G2. When the height of the pixel wall 127 exceeds 20 times the height of the hydrophobic liquid material 132 in a state where no voltage is applied, the voltage required for the hydrophilic material 130 to push the hydrophobic liquid material 132 is very high. Therefore, the TFT 121 needs to have a withstand voltage, and a short circuit due to a leakage current is likely to occur. The more preferable lower limit of the height of the pixel wall 127 is four times the height of the hydrophobic liquid material 132 when no voltage is applied, and the more preferable upper limit is the height of the hydrophobic liquid material 132 when no voltage is applied. 10 times.
If the height of the pixel wall 127 is within this range, even if each pixel is sealed in the pixel wall when it has the same length as the cell gap, that is, the surface of the pixel wall becomes hydrophobic. Therefore, the movement of the hydrophobic material, that is, the pixel switching is possible.

  In the electrowetting display 100, as shown in FIG. 3, when a predetermined voltage (for example, 30V) is applied to the pixel electrode 124 on the second substrate 120 side, a lateral electric field is generated between the pixel electrode 124 and the common electrode 125. Thus, the hydrophobicity of the surface of the pixel electrode 124 is eased and the hydrophilicity becomes stronger, so that the hydrophilic material 130 can be attracted. At this time, the shape of the hydrophobic liquid material 132 familiar to the pixel G <b> 2 changes so as to be convex on the common electrode 125 by the force of the hydrophilic material 130.

  In this way, by selectively moving the hydrophobic liquid material 132 in the pixel G2 onto the common electrode 125, the light that has passed through the filter portions 30R, 30G, and 30B of the color filter layer 30 provided in the lower layer is first generated. It is possible to switch between a state of transmitting to the substrate 110 side and a state of shielding light.

  On the other hand, as shown in FIG. 4, the electrowetting display 100 applies a predetermined voltage to the pixel electrode 114 on the first substrate 110 side. At this time, the hydrophilic material 130 and the pixel electrode 114 function as a pair of electrodes, and an electric field is generated between the pixel electrode 114 and the hydrophilic material 130. As a result, the shape of the hydrophobic liquid material 131 that has become familiar with the pixel G <b> 1 is changed into a recessed state due to the force of the hydrophilic material 130.

FIGS. 5A and 5B are diagrams showing a configuration according to a modified example of the first substrate 110.
As shown in FIG. 5A, a protrusion 50 lower than the first pixel wall 117 may be formed on the pixel G1. Further, as shown in FIG. 5B, with respect to the hydrophobic intermediate layer 128 covering the surface of the first pixel wall 117, the thickness in the vicinity of the base portion of the first pixel wall 117 is increased so that the hydrophobic intermediate layer 128 in the pixel G1 The thickness of the layer 128 may be varied.

  As shown in FIGS. 5A and 5B, the protrusion 50 and the hydrophobic intermediate layer 128 are made different in thickness so that they are surrounded by the pixel wall 117 when no voltage is applied. The hydrophobic liquid material 131 stored in the region has a portion having a large thickness and a portion having a small thickness, and the electric field generated in the hydrophobic liquid material 131 varies (inhomogeneity). Can do. Therefore, a trigger for deforming the shape of the hydrophobic liquid material 131 can be applied, and the hydrophobic liquid material 131 can be easily deformed. Therefore, the responsiveness of the lenticular lens can be improved by increasing the speed at which the shape of the hydrophobic liquid material 131 changes.

  The hydrophobic liquid material 131 can function as a lens by changing the interface shape between the hydrophobic liquid material 131 having light permeability and the hydrophilic material 130. In this embodiment, since the refractive index of the hydrophilic material 130 is set higher than that of the hydrophobic liquid material 131, the hydrophobic liquid material 131 functions as a concave lens (lenticular lens).

  As described above, the electrowetting display 100 moves the hydrophobic liquid material 132 onto the common electrode 125 in the desired pixel G2 on the second substrate 120 side, thereby causing the light passing through the color filter layer 30 to pass through the color filter layer 30 for each pixel G2. It is possible to function as a lenticular lens by transmitting the light to the one substrate 110 side and changing the interface shape of the hydrophobic liquid material 131 and the hydrophilic material 130 on the first substrate 110 side.

  FIG. 6 is a conceptual diagram for explaining a stereoscopic image display operation by the electrowetting display 100. As shown in FIG. 6, the electrowetting display 100 moves the hydrophobic liquid material 132 in the pixel G2 onto the common electrode 125 by applying a voltage to the pixel electrode 124 on the second substrate 120 side (see FIG. 6). The right-eye image R and the left-eye image L are generated by the light that has passed through the color filter layer 30 (filter units 30R, 30G, and 30B).

  On the other hand, on the first substrate 110 side, by applying a voltage to the pixel electrode 114, an electric field is generated between the pixel electrode 114 and the hydrophilic material 130, and the hydrophobic liquid material 132 in the pixel G1 and The hydrophobic liquid material 132 is caused to function as a lenticular lens by deforming the interface shape of the hydrophilic material 130 to be concave.

  The image R for the right eye that has entered the lenticular lens made of the hydrophobic liquid material 132 is condensed so as to enter the right eye of the observer H. Similarly, the image L for the left eye that has entered the lenticular lens made of the hydrophobic liquid material 132 is condensed so as to enter the left eye of the observer H.

  As described above, according to the electrowetting display 100 according to the present embodiment, the first substrate 110 side functions as a lenticular lens, and the right eye image R and the left eye image L are transmitted through the second substrate 120 side. By functioning as a shutter, it is possible to make the viewer H visually recognize a stereoscopic image without using special glasses. Further, since the electrowetting display 100 does not need to use a polarizing plate unlike a liquid crystal display, the light utilization efficiency is high and a bright stereoscopic image can be displayed. In addition, the electrowetting display 100 employs a configuration in which the first substrate 110 and the second substrate 120 are bonded together with a common hydrophilic material 130, thereby realizing a reduction in size and thickness of the display itself. .

  The electrowetting display 100 can be used as a display for displaying a two-dimensional image unless the interface shape of the hydrophobic liquid material 132 and the hydrophilic material 130 is changed on the first substrate 110 side. In this case, on the second substrate 120 side, light passing through the same color filter layer 30 (filter units 30R, 30G, 30B) is the same pixel in the display image (a pixel common to the right-eye image and the left-eye image). ).

  In addition, according to the present embodiment, the height of the pixel walls 117 and 127 is set to 2 to 20 times the height of the hydrophobic liquid materials 131 and 132 in the voltage non-applied state (see FIG. 2). Contamination (display unevenness) of the display screen due to the hydrophobic liquid materials 131 and 132 getting over the pixel walls 117 and 127 can be suppressed, and a high-quality stereoscopic image can be displayed.

  The surface of the first substrate 110 on the side having the first pixel wall 117 and the pixel wall 117 and the surface of the second substrate 120 on the side having the second pixel wall 127 and the pixel wall 127 are formed by the hydrophobic intermediate layer 128. Since it is made hydrophobic, the hydrophobic liquid materials 131 and 132 are uniformly stored, and the interface shape between the hydrophilic material 130 and the hydrophobic liquid materials 131 and 132 when the application of voltage is stopped. High-speed stereoscopic image can be displayed with high responsiveness and reduced non-uniformity by speeding up the change.

  In addition, the electrowetting display 100 can change the degree of depression of the interface shape between the hydrophobic liquid material 132 and the hydrophilic material 130 by changing the voltage applied to the pixel electrode 114 on the first substrate 110 side. is there. That is, the electrowetting display 100 can change the focal length of the lenticular lens in accordance with the amount of depression of the hydrophobic liquid material 132. Thereby, the electrowetting display 100 can change the optimal viewing distance with respect to the display of the observer H.

  For example, the electrowetting display 100 increases the curvature of the lenticular lens by reducing the dent amount of the hydrophobic liquid material 132 by relatively lowering the applied voltage to the pixel electrode 114, and thereby observing the viewer H with respect to the display. The optimum viewing distance (focal length) can be increased.

  On the other hand, the electrowetting display 100 reduces the curvature of the lenticular lens by increasing the dent amount of the hydrophobic liquid material 132 by relatively increasing the applied voltage to the pixel electrode 114, and the observer H with respect to the display The optimal viewing distance (focal length) can be shortened.

  As described above, the electrowetting display 100 is a multifunctional display that can change the optimal viewing distance for the observer H in various ways by varying the voltage applied to the pixel electrode 114 on the first substrate 110 side.

(Second Embodiment)
Next, the configuration of the electrowetting display according to the second embodiment will be described. The difference between this embodiment and 1st Embodiment is the system which displays a stereo image. Specifically, the first embodiment includes a pair of substrates each having an electrowetting device formed thereon, and one substrate side functions as an image display unit that displays an image for the right eye and an image for the left eye, and the other By making the substrate side function as a lenticular lens, the right eye image and the left eye image are visually recognized by an observer so that a stereoscopic image can be viewed.

  In contrast, the present embodiment includes a pair of substrates each having an electrowetting device formed thereon, and one substrate side functions as an image display unit that displays an image for the right eye and an image for the left eye, and the other This invention relates to a display that allows a viewer to visually recognize a stereoscopic image by spatially separating a right-eye image and a left-eye image by causing the substrate side to function as a parallax barrier. In the present description, the same components and members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

FIG. 7 is a schematic view showing a cross-sectional configuration of an electrowetting display according to the second embodiment.
As shown in FIG. 7, the electrowetting display 200 according to the present embodiment includes a first substrate 210 and a second substrate 120, and the substrates 210 and 120 are arranged to face each other with a hydrophilic material 130 interposed therebetween. ing. The hydrophilic material 130 is disposed in a region defined by a seal member 140 (not shown) provided along the outer periphery of the substrates 210 and 120.

  A first pixel wall 117 is formed on the insulating film 116 of the first substrate 210. In the present embodiment, the pixel electrode 114 is formed so as to straddle a region (hereinafter also referred to as a pixel G1) partitioned by the first pixel wall 117. The first pixel wall 117 is disposed so as to be located at the approximate center of the pixel electrode 114. In addition, a hydrophobic liquid material (first hydrophobic liquid material) 231 is stored in the pixel G1.

  In this embodiment, since the first substrate 210 side is used as a parallax barrier, a hydrophobic liquid having a light shielding property is used as the hydrophobic liquid material 231. For example, a pigment that contains a dye and / or pigment that does not allow visible light to pass through a hydrophobic solvent is used. The hydrophobic solvent is not particularly limited, and examples thereof include alkanes such as decane, undecane, dodecane, and hexadecane, silicone oil, and fluorocarbon. These hydrophobic solvents may be used alone or in combination of two or more. In this embodiment, decane (refractive index; 1.411) was used.

  The dye or the pigment is not particularly limited. For example, various pigments and dyes such as inorganic, phthalocyanine, and azo organics can be used, but as a solution characteristic used for electrowetting, a hydrophobic liquid However, it is necessary not to dissolve in a hydrophilic liquid, and the pigment surface is appropriately subjected to hydrophobic treatment. For example, there are metal oxides such as iron and chromium, and sulfides. There are also reductants such as titanium oxide and carbons such as ketjen black. Metal complexes such as iron are also used.

  In the present embodiment, a hydrophobic pigment mixture in which carbon black having a hydrophobic surface is dissolved in sadecan at a concentration of 5 wt% is used as the hydrophobic liquid material 132.

  A second pixel wall 127 is formed on the second insulating film 126b of the second substrate 120, and a region (pixel G2) defined by the second pixel wall 127 is hydrophobic as in the first embodiment. An ionic liquid material 132 is stored.

  FIG. 8 is a schematic diagram for explaining the operation of the electrowetting display 200. As shown in FIG. 8, the electrowetting display 200 applies a predetermined voltage (for example, 30 V) to the pixel electrode 124 on the second substrate 120 side, so that the hydrophobicity of the surface of the pixel electrode 124 is reduced and the hydrophilicity is reduced. The hydrophilic material 130 can be attracted by becoming stronger. At this time, the shape of the hydrophobic liquid material 132 that has become familiar in the pixel G <b> 2 is changed to a convex shape on the common electrode 125 by the force of the hydrophilic material 130.

  In this way, by selectively moving the hydrophobic liquid material 132 in the pixel G2 onto the common electrode 125, the light that has passed through the filter portions 30R, 30G, and 30B of the color filter layer 30 provided in the lower layer is first generated. It is possible to switch between a state of transmitting to the substrate 210 side and a state of shielding light.

  On the other hand, the electrowetting display 200 applies a predetermined voltage to the pixel electrode 114 on the first substrate 210 side, as shown in FIG. At this time, the hydrophilic material 130 functions as an electrode, and an electric field is generated between the pixel electrode 114 and the hydrophilic material 130. As a result, the shape of the hydrophobic liquid material 231 that has become familiar in the pixel G <b> 1 is changed to a recessed state by the force of the hydrophilic material 130.

  In the present embodiment, when an electric field is generated between the pixel electrode 114 and the hydrophilic material 130, the shape of the hydrophobic liquid material 231 changes so as to be pressed toward the first pixel wall 117 by the electric field. In the present embodiment, since the pixel electrode 114 is formed so as to straddle between adjacent pixels G1, the hydrophobic liquid material 231 is in a state of being separated at the center in each pixel G1. When the hydrophobic liquid material 231 is drawn toward the first pixel wall 117 side, a transmission region that transmits light from the second substrate 120 side and a light shielding region that blocks light are formed on the first substrate 110 side. The transmission region constitutes a barrier opening S in the parallax barrier.

  In the pixel G <b> 2 on the second substrate 120 side, the hydrophobic liquid material 132 moves onto the common electrode 125, so that light passing through the color filter layer 30 can be transmitted to the first substrate 110 side for each pixel G <b> 2. .

FIG. 9 is a view for explaining stereoscopic image display on the electrowetting display 200 according to the present embodiment.
The first substrate 210 moves the hydrophobic liquid material 231 toward the first pixel wall 117 in the pixel G1, thereby generating the right-eye image R generated on the second substrate 120 side as shown in FIG. A plurality of barrier openings S corresponding to the left-eye image L are formed in the pixel G1. In the barrier opening S formed by the first substrate 210, the left-eye image L is incident on the left eye of the observer H and the right-eye image R is incident on the right eye of the observer H. On the other hand, in the area where the barrier opening S is not formed on the first substrate 210, the left-eye image L is prevented from entering the right eye of the observer H, and the right-eye image R is incident on the left eye of the observer H. Can be prevented. Therefore, the first substrate 210 has a function as a parallax barrier.

  In addition, the electrowetting display 200 can control the amount of the hydrophobic liquid material 231 that moves to the first pixel wall 114 side by varying the voltage applied to the pixel electrode 114 on the first substrate 210 side. It is.

  FIG. 10 is a diagram for explaining the relationship between the voltage applied to the pixel electrode 114 and the barrier opening S. FIG. 10A shows a state in which no voltage is applied to the pixel electrode 114, and FIG. The case where the voltage applied to the pixel electrode 114 is small is shown, and FIG. 4C shows the case where the voltage applied to the pixel electrode 114 is large.

  As shown in FIG. 10A, when no voltage is applied to the pixel electrode 114, no barrier opening is formed. As shown in FIGS. 10B and 10C, the electrowetting display 200 has a barrier opening in the parallax barrier according to the magnitude of the applied voltage to the pixel electrode 114 (that is, the amount of movement of the hydrophobic liquid material 231). The magnitude of S can be changed. That is, the electrowetting display 200 can change the ratio of the light transmission region and the light shielding region from the second substrate 120 side. Thereby, the electrowetting display 200 can change the optimal viewing distance of the observer H with respect to the display by adjusting the width of the barrier opening S.

FIG. 11 is a diagram for explaining a change in the size of the barrier opening S. FIG. 11A shows a state in which the width of the barrier opening S is large, and FIG. 11B shows a state in which the width of the barrier opening S is small. It shows the state.
As shown in FIG. 11A, the electrowetting display 200 reduces the amount of movement of the hydrophobic liquid material 231 toward the first pixel wall 114 by relatively reducing the applied voltage to the pixel electrode 114. By reducing the width, the width of the barrier opening S of the parallax barrier can be reduced. Thereby, the electrowetting display 200 can extend the optimal viewing distance d for the observer H. Therefore, the electrowetting display 200 can make the viewer H visually recognize the stereoscopic image from a farther position.

  On the other hand, as shown in FIG. 11B, the electrowetting display 200 increases the amount of movement of the hydrophobic liquid material 231 onto the common electrode 115 by relatively increasing the applied voltage to the pixel electrode 114. By doing so, the width of the barrier opening S of the parallax barrier can be increased. Thereby, the electrowetting display 200 can shorten the optimal viewing distance d for the observer H. Therefore, the electrowetting display 200 can make the viewer H visually recognize the stereoscopic image from a closer position.

  As described above, according to the electrowetting display 200 according to the present embodiment, the first substrate 110 side functions as a parallax barrier, and the second substrate 120 side transmits the right-eye image R and the left-eye image L. By functioning as a shutter, it is possible to make the viewer H visually recognize the stereoscopic image satisfactorily without using special glasses. Further, by making the width of the barrier opening S of the parallax barrier variable, it becomes a multifunctional display that can change the optimum viewing distance for the observer H in various ways.

  The electrowetting display 200 can be used as a display for displaying a two-dimensional image by maximizing the width of the barrier opening S by applying a maximum voltage to the pixel electrode 114. In this case, on the second substrate 120 side, light passing through the same color filter layer 30 (filter units 30R, 30G, 30B) is the same pixel in the display image (a pixel common to the right-eye image and the left-eye image). ).

(Third embodiment)
Next, the configuration of the electrowetting display according to the third embodiment will be described. The difference between the present embodiment and the second embodiment is the driving method of the first substrate 210. In the present description, the same components and members as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

FIG. 12 is a schematic view showing a cross-sectional configuration of the electrowetting display according to the third embodiment.
As shown in FIG. 12, the electrowetting display 300 according to the present embodiment includes a first substrate 310 and a second substrate 120, and these substrates 310 and 120 are arranged to face each other with a hydrophilic material 130 interposed therebetween. ing. The hydrophilic material 130 is disposed in a region defined by a seal member 140 (not shown) provided along the outer periphery of the substrates 310 and 120.

  FIG. 13 is a schematic view showing a planar configuration of the first substrate 310. As shown in FIG. 13, a pixel electrode pair 210 is formed on the first substrate 310 according to the present embodiment. The pixel electrode pair 210 includes a plurality of stripe-shaped first pixel electrodes 214 and a plurality of stripe-shaped second pixel electrodes 215.

  The plurality of first pixel electrodes 214 are electrically connected to each other through a wiring portion 214a. The plurality of second pixel electrodes 215 are electrically connected to each other by the wiring portion 215a. That is, the plurality of first pixel electrodes 214 are applied with a voltage simultaneously through the wiring portion 214a. In addition, the plurality of second pixel electrodes 215 are simultaneously applied with voltages via the wiring portion 215a.

  The first pixel electrode 214 and the second pixel electrode 215 are formed on the first substrate 310 so as to mesh with each other in a comb shape. As a result, the first pixel electrode 214 and the second pixel electrode 215 are alternately formed on the first substrate 310.

  Returning to FIG. 12, the first pixel wall 117 formed on the insulating film 116 of the first substrate 310 is disposed at a position overlapping with the center of the first pixel electrode 214 and the second pixel electrode 215 in a plan view. Has been. In other words, the first pixel electrode 214 and the second pixel electrode 215 are arranged so as to cross the pixels G1 alternately on the first substrate 310, respectively. Each pixel G1 stores a hydrophobic liquid material (first hydrophobic liquid material) 231.

  In the electrowetting display 200, by applying a predetermined voltage (for example, 30V) to the pixel electrode 124 on the second substrate 120 side, the hydrophobicity of the surface of the pixel electrode 124 is reduced, and the hydrophilicity becomes stronger. The hydrophilic material 130 can be attracted (see FIG. 8). At this time, the shape of the hydrophobic liquid material 132 that has become familiar in the pixel G <b> 2 is changed to a convex shape on the common electrode 125 by the force of the hydrophilic material 130.

  In this way, by selectively moving the hydrophobic liquid material 132 in the pixel G2 onto the common electrode 125, the light that has passed through the filter portions 30R, 30G, and 30B of the color filter layer 30 provided in the lower layer is first generated. It is possible to switch between a state of transmitting to the substrate 210 side and a state of shielding light.

  The electrowetting display 300 applies a predetermined voltage to the pixel electrode pair 210 on the first substrate 310 side. Specifically, the electrowetting display 300 applies a voltage to one of the first pixel electrode 214 and the second pixel electrode 215. In the electrowetting display 300, the voltage to be applied can be switched between the first pixel electrode 214 and the second pixel electrode 215. The electrowetting display 300 applies a voltage to the first pixel electrode 214 using the wiring part 214a. Further, the electrowetting display 300 applies a voltage to the second pixel electrode 215 using the wiring part 215a.

  Based on such a configuration, the electrowetting display 300 moves the position of the barrier opening as described later by selectively applying a voltage to the first pixel electrode 214 and the second pixel electrode 215. It is possible.

FIG. 14 is a schematic diagram for explaining the operation of the electrowetting display 300 on the first substrate 310 side.
In the period T shown in FIG. 14A, the electrowetting display 300 applies a predetermined voltage to the plurality of second pixel electrodes 215 via the wiring portion 215a. At this time, the hydrophilic material 130 functions as an electrode, and an electric field is generated between each second pixel electrode 215 and the hydrophilic material 130. As a result, the shape of the hydrophobic liquid material 231 that has become familiar in the pixel G <b> 1 is changed to a recessed state by the force of the hydrophilic material 130.

  In the present embodiment, when an electric field is generated between the second pixel electrode 215 and the hydrophilic material 130, the hydrophobic liquid material 231 is pressed toward the first pixel wall 117 formed on the second pixel electrode 215 side by the electric field. The shape changes. At this time, since no voltage is applied to the first pixel electrode 214, no electric field is generated between the first pixel electrode 214 and the hydrophilic material 130. Therefore, the movement of the hydrophobic liquid material 231 occurs only in the region corresponding to the second pixel electrode 215 in the pixel G1, and the movement of the hydrophobic liquid material 231 does not occur in the region corresponding to the first pixel electrode 214.

  When the hydrophobic liquid material 231 is drawn toward the first pixel wall 117 side, a transmission region that transmits light from the second substrate 120 side and a light shielding region that blocks light are formed on the first substrate 110 side. Note that the first pixel wall 117 on the second pixel electrode 215 and the hydrophobic liquid material 231 pressed against the first pixel wall 117 actually block the light from the second substrate 120 side. Since it is sufficiently narrow compared with other transmission regions, it can be ignored. Therefore, in this specification, a region corresponding to the second pixel electrode 215 to which a voltage is applied is referred to as a transmission region, and a region corresponding to the first pixel electrode 214 to which a voltage is not applied is referred to as a light shielding region. The same applies to the description of FIG.

Therefore, the transmission region constitutes the barrier opening S in the parallax barrier. In the present embodiment, a half area of the adjacent pixel G1 is integrated to form one barrier opening S.
As described above, a plurality of barrier openings S can be formed on the first substrate 110 side.

  Further, the electrowetting display 300 performs switching so as to apply a predetermined voltage to the plurality of first pixel electrodes 214 via the wiring portion 214a in the period T2 shown in FIG. 14B. At this time, the hydrophilic material 130 functions as an electrode, and an electric field is generated between each first pixel electrode 214 and the hydrophilic material 130. As a result, the shape of the hydrophobic liquid material 231 that has become familiar in the pixel G <b> 1 is changed to a recessed state by the force of the hydrophilic material 130.

In the present embodiment, when an electric field is generated between the first pixel electrode 214 and the hydrophilic material 130, the hydrophobic liquid material 231 is pressed toward the first pixel wall 117 formed on the first pixel electrode 214 side by the electric field. The shape changes. At this time, since no voltage is applied to the second pixel electrode 215, no electric field is generated between the second pixel electrode 215 and the hydrophilic material 130. Accordingly, in the pixel G1, the movement of the hydrophobic liquid material 231 occurs only in the region corresponding to the first pixel electrode 214, and the movement of the hydrophobic liquid material 231 does not occur in the region corresponding to the second pixel electrode 215.
As described above, a plurality of barrier openings S can be formed on the first substrate 110 side.

  In the present embodiment, since the first pixel electrode 214 and the second pixel electrode 215 are arranged at different positions as described above, the position of the barrier opening S is set as shown in FIGS. The first pixel wall 117 (the first pixel electrode 214 and the second pixel electrode 215) can be moved by the arrangement pitch.

  FIG. 15 is a view for explaining stereoscopic image display on the electrowetting display 300 according to the present embodiment. 14A is a diagram showing a state corresponding to the period T1 described in FIG. 14A, and FIG. 14B is a diagram showing a state corresponding to the period T2 described in FIG. is there.

  As shown in FIG. 15A, in the period T1, the barrier opening S causes the left eye image L to be incident on the left eye of the observer H and the right eye image R is incident on the right eye of the observer H. Let On the other hand, in the area where the barrier opening S is not formed on the first substrate 310, the left-eye image L is prevented from entering the right eye of the observer H and the right-eye image R is incident on the left eye of the observer H. Can be prevented.

  As illustrated in FIG. 15B, in the period T <b> 2, the barrier opening S whose position is shifted by one pitch of the first pixel wall 117 causes the left-eye image L to enter the left eye of the observer H. At the same time, the image R for the right eye is incident on the right eye of the observer H. On the other hand, in the area where the barrier opening S is not formed, the left-eye image L is prevented from entering the right eye of the observer H and the right-eye image R is prevented from entering the observer H's left eye. be able to.

  In the electrowetting display 300 according to the present embodiment, when the position of the barrier opening S is shifted in the above-described periods T1 and T2, the image R for the right eye and the left generated at each pixel G2 of the second substrate 120 are combined. The position of the eye image L is switched. According to this, since the image R for the right eye and the image L for the left eye can be generated using all the pixels G2 of the second substrate 120, the resolution is lower than that of the parallax barrier type stereoscopic image display. A high stereoscopic image can be visually recognized by the viewer H.

  The electrowetting display 300 generates barrier openings S in all the pixels G1 by simultaneously applying a voltage to the first pixel electrode 214 and the second pixel electrode 215 via the wiring portions 214a and 215a. It can be used as a display for displaying a two-dimensional image. In this case, on the second substrate 120 side, light passing through the same color filter layer 30 (filter units 30R, 30G, 30B) is the same pixel in the display image (a pixel common to the right-eye image and the left-eye image). ).

  The preferred embodiment of the present invention has been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such an example. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  Moreover, in the said 2nd Embodiment, although the structure which applies the same voltage about the pixel electrode 114 arrange | positioned at each pixel G1 was mentioned as an example, this invention is not limited to this. For example, a configuration in which the applied voltage is different for each predetermined region (viewing region) of the electrowetting display 200 may be employed. FIG. 16 is a schematic view showing a planar configuration of the first substrate 210 according to this modification.

  As shown in FIG. 16, the first substrate 210 is provided with a first pixel electrode group 220, a second pixel electrode group 221, and a third pixel electrode group 222. The first pixel electrode group 220 includes a plurality of stripe-shaped pixel electrodes 220a, and the pixel electrodes 220a are electrically connected via the wiring portion 220b. The first pixel electrode group 220 is for configuring a barrier opening S corresponding to the observer H who visually recognizes a stereoscopic image from the left side with respect to the front direction of the electrowetting display 200.

  The second pixel electrode group 221 includes a plurality of stripe-shaped pixel electrodes 221a, and the pixel electrodes 221a are electrically connected via a wiring portion 221b. The second pixel electrode group 221 is for configuring the barrier opening S corresponding to the observer H who visually recognizes the stereoscopic image from the front direction of the electrowetting display 200.

  The third pixel electrode group 222 includes a plurality of stripe-shaped pixel electrodes 222a, and the pixel electrodes 222a are electrically connected through a wiring portion 222b. The third pixel electrode group 222 is for forming a barrier opening S corresponding to the observer H who visually recognizes a stereoscopic image from the right side with respect to the front direction of the electrowetting display 200.

  According to the electrowetting display 200 according to this configuration, the first pixel electrode group 220, the second pixel electrode group 221, and the third pixel electrode group 222 can be independently applied to the pixel electrodes 220a, 221a, and 222a. Since the magnitude of the voltage to be applied can be made different, it is possible to visually recognize a good stereoscopic image by forming an optimum barrier opening S corresponding to a plurality of observers H in different directions. Can provide a display.

DESCRIPTION OF SYMBOLS 30 ... Color filter layer, 30R, 30G, 30B ... Filter part, 100 ... Electrowetting display, 110 ... 1st board | substrate, 110 ... 2nd board | substrate, 111 ... TFT (drive part), 117 ... 1st pixel wall, DESCRIPTION OF SYMBOLS 120 ... 2nd board | substrate, 121 ... TFT (driving part), 127 ... 2nd pixel wall, 128 ... Hydrophobic intermediate | middle layer, 130 ... Hydrophilic material, 131,231 ... Hydrophobic liquid material (1st hydrophobic liquid) Material), 132... Hydrophobic liquid material (second hydrophobic liquid material), 200... Electrowetting display

Claims (6)

Each of a pair of substrates constituting one cell is an electrowetting display having a drive unit,
A first substrate storing a first hydrophobic liquid material in a region surrounded by a first pixel wall, and a second substrate storing a second hydrophobic liquid material in a region surrounded by a second pixel wall Are bonded to each other through a hydrophilic material,
On the first substrate side, a voltage is applied to the first hydrophobic liquid material to change the interface shape between the first hydrophobic liquid material and the hydrophilic material, thereby functioning as a lens. Let
On the second substrate side, a voltage is applied to the second hydrophobic liquid material to change the interface shape between the second hydrophobic liquid material and the hydrophilic material, thereby changing the color filter layer. An electrowetting display that functions as a shutter that transmits light passing through the first substrate to the first substrate side. Each of a pair of substrates constituting one cell is an electrowetting display having a drive unit,
A first substrate storing a first hydrophobic liquid material in a region surrounded by a first pixel wall, and a second substrate storing a second hydrophobic liquid material in a region surrounded by a second pixel wall Are bonded to each other through a hydrophilic material,
On the first substrate side, as a parallax barrier, a voltage is applied to the first hydrophobic liquid material to change an interface shape between the first hydrophobic liquid material and the hydrophilic material. Make it work
On the second substrate side, a voltage is applied to the second hydrophobic liquid material to change the interface shape between the second hydrophobic liquid material and the hydrophilic material, thereby changing the color filter layer. An electrowetting display that functions as a shutter that transmits light passing through the first substrate to the first substrate side.   The hydrophobic liquid material having a light shielding property is stored as the first hydrophobic liquid material in each of the regions surrounded by the first pixel walls. Electrowetting display.   The electrowetting display according to any one of claims 1 to 3, wherein the hydrophilic material is a gel substance.   The height of at least one of the first pixel wall and the second pixel wall is set to 2 to 20 times the height of the hydrophobic liquid material stored therein in a voltage non-application state. The electrowetting display according to any one of claims 1 to 4.   6. The surface of the side having the pixel wall and the pixel wall in at least one of the first substrate and the second substrate are hydrophobic, according to claim 1. Electrowetting display.

Images