JP2005173140A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To heighten visibility in observation from an inclined direction by improving a viewing angle in a display device which displays a picture by moving mobile plates in cell shaped regions filled with liquid by an action of an electric field. <P>SOLUTION: A surface of a lateral part 13 of a partition wall 10 to enclose a transparent liquid 20M and a colored mobile plate 30 in the cell shaped region 15 is made to be a light reflection surface. Light incident on the inside of the cell shaped region 15 is reflected on the light reflection surface, so as to increase light quantity in a direction inclined against a display direction (an arrow Z direction in the figure). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a display device, and more particularly to a display device that displays an image formed by moving a movable body that can move in a liquid by the action of an electric field.

Conventionally, there has been known a display device that displays an image formed by moving a movable body that can move in a liquid by the action of an electric field. As a reflection type display device, for example, when displaying a white color by arranging a plurality of microcapsules containing a liquid containing a large number of fine particles in a two-dimensional manner to individually apply an electric field to each microcapsule. A technique is known in which fine particles in a microcapsule are moved to the display side by the action of an electric field and these fine particles are randomly dispersed without causing an electric field to act on the fine particles in the microcapsule when displaying black (Patent Document). 1). Further, as a transmissive display device, for example, a partition that divides a region between two opposing transparent substrates into partial regions corresponding to a plurality of different regions in a plane orthogonal to the opposing direction. There is known a display device that displays an image by moving a large number of fine particles dispersed in a transparent liquid filling each partial region by the action of an electric field (see Patent Document 2).
JP 2000-66247 A Japanese Patent Laid-Open No. 08-190351

  However, when the display in one pixel is performed using a large number of fine particles as in the display device, for example, in the reflective display device, a large number of illumination light incident on the microcapsule corresponding to one pixel is transmitted. When displaying white by reflecting with fine particles, light incident on the gaps between the fine particles or light incident at a shallow angle with respect to the fine particles is not reflected on the display side and is not used for the white display. Therefore, the contrast ratio of displayed white and black may be reduced. Further, for example, in the transmissive display device, when the illumination light incident on the partial region corresponding to one pixel is blocked by a large number of fine particles to display black, the display is flat in a direction orthogonal to the facing direction. Although the light is blocked by a large number of fine particles arranged in the same manner, the light may leak from the gaps between the fine particles arranged in the plane, and the contrast ratio of white and black may be reduced as described above.

  Therefore, as a display device that can increase the contrast ratio in the display, the moving plate (which enables light absorption, reflection, light shielding, etc.) is moved in the transparent liquid sealed in each cell, thereby moving the cell to the cell. A display device that controls the wavelength, light amount, and the like of incident light has been studied by the present applicant.

  This display device includes a partition wall that divides a plurality of cellular regions arranged along a display surface, and moves a colored moving plate disposed in a transparent liquid that fills each cellular region by the action of an electric field. Image display, and it can suppress light absorption when reflecting light with a colored moving plate, or light leakage when blocking light with a colored moving plate, and increase the extinction ratio. Therefore, the contrast ratio in display can be increased. In addition, there is an advantage that the aperture ratio is high and the light use efficiency is high. Taking advantage of this advantage, it can be applied to an optical shutter that turns light transmission on and off.

  However, in the display device using the moving plate under consideration, there is still room for improvement in view angle and visibility. For example, as shown in FIG. 5 (1), the illuminating device 51 is set so that the colored moving plate 30 in the cellular region 15 surrounded by the partition wall 10 is perpendicular to the display direction (the arrow Z direction in the figure). When the white light Lv incident on the cell-like region 15 is cut off, that is, when it corresponds to black display, the black display is not observed even if the display device is observed from a direction (diagonal direction) non-parallel to the display direction. Although it is recognized as a black display as it is, as shown in FIG. 5B, the white light Lv incident on the cellular region 15 from the illumination device 51 is placed with the colored moving plate 30 in a position parallel to the display direction. In the case of transmission, that is, in the case of white display, when the display device is observed from a direction (diagonal direction) non-parallel to the display direction, the colored moving plate 30 and the side portion 13 of the partition wall are directly observed. Black display even during white display There is a case to be erroneously recognized. From another point of view, the white light Lv emitted from the lighting device 51 is absorbed by the colored moving plate 30 and the side portion 13, and it cannot be said that a sufficient amount of light is obtained in the oblique direction. Yes (see FIG. 6).

  For this reason, the display device under examination has a problem that the viewing angle is narrow and the visibility when viewed from an oblique direction is poor.

  In view of the above circumstances, the present invention is a display device that displays an image formed by moving a colored moving body that can move in a liquid by the action of an electric field, and has a wider viewing angle and is observed from an oblique direction. It is an object of the present invention to provide a display device with improved visibility.

  The first display device of the present invention includes a plurality of cellular regions disposed along a plane orthogonal to the display direction, a transparent liquid filling each cellular region, and each surrounding each cellular region, A partition wall whose display side is transparent, a colored moving plate that is arranged in each cellular region and that can move in each cellular region, and an electric field that acts on the colored moving plate is formed, and the electric field is changed And the electric field forming means for positioning the colored moving plate at a first position where the main surface intersects the display direction and a second position where the main surface is substantially parallel to the display direction. The surface of the side portion of the wall is a light reflecting surface.

  In addition, the second display device of the present invention surrounds each of the plurality of cellular regions arranged along the plane orthogonal to the display direction, the transparent liquid filling each cellular region, and each cellular region. A partition wall having at least a display side portion, a colored moving plate disposed in each cellular region, movable in each cellular region, an electric field acting on the colored moving plate, and the electric field And the electric field forming means for positioning the colored moving plate at a first position where the main surface intersects the display direction and a second position where the main surface is substantially parallel to the display direction, At least a part of the main surface of the colored moving plate is a light reflecting surface.

  Here, the “display direction” means a direction perpendicular to the display surface on which display is performed.

  In addition, the “cellular area” means a three-dimensional area of a cell represented by a shape such as a cube, a rectangular parallelepiped, a cylinder, a polygonal column, etc., and the cell-like areas may be arranged in contact with each other. Alternatively, they may be arranged apart from each other.

  In addition, “transparent liquid” means a liquid having optical transparency and is not limited to a colorless and transparent liquid. However, in order to obtain high luminance and a high contrast ratio in image display, a liquid having high transparency is used. Is preferred.

  The “partition wall” means a wall provided so as to surround each cellular area three-dimensionally. The cellular area can be filled with a transparent liquid, and the colored moving plate is placed in the cellular area. Any structure may be used as long as it can be disposed in the structure. For example, the entire wall may be continuous, or at least a part of the wall may be discontinuous, for example, a network structure.

  The “display side” of the partition wall means the side on which the image is displayed.

  The “side portion” of the partition wall means a wall extending in a direction substantially parallel to the display direction among the walls constituting the partition wall.

  The “colored moving plate” is a colored plate that can be moved by receiving an action from an electric field. For example, a carbon plate can be considered. In addition, a plurality of “colored moving plates” may be arranged for each cellular region, and for example, a form like a double door (so-called double door) may be used.

  The “colored moving plate” may be rotatably supported in the cellular region.

  Further, “rotatable” does not mean only a state in which one rotation is possible, but also includes a so-called rotatable state that can move within a predetermined angle range around the rotation axis.

  The “main surface” means a surface orthogonal to the thickness direction of the colored moving plate.

  The “electric field forming means” may be one that forms a DC electric field or one that forms an AC electric field. However, in order to suppress electrolysis due to the electric field of the transparent liquid, the electric field is unidirectional. An AC electric field that is not continuously formed is preferred.

  When an electric field is formed by the electric field forming means, the colored moving plate tries to take the most stable posture in which the electrostatic energy in the system including the transparent liquid in the cellular region and the colored moving plate is minimized. An attempt is made to direct the main surface in a direction parallel to the direction of the electric field. Using this phenomenon, the rotational position of the colored moving plate can be controlled. In order to change the electrostatic energy depending on the position of the colored moving plate, the dielectric constant of the colored moving plate needs to be different from the dielectric constant of the colored moving plate. The greater the difference between the rate and the dielectric constant of the transparent liquid, the greater the force acting on the colored moving plate and the easier it will rotate.

  As the “electric field forming means”, for example, each colored moving plate is formed with a first electric field that forms an electric field in a direction perpendicular to the display direction (a direction parallel to the display surface) so that the initial position is the first position. An electric field forming unit and a second electric field forming unit that forms an electric field in a direction parallel to the display direction for changing the colored moving plate at the initial position to the second position can be considered. . As the first electric field forming means, for example, a device that applies a DC voltage or an AC voltage to an electrode provided so as to sandwich the entire cellular region in a direction parallel to the display surface can be used. As the electric field forming means, for example, for each cell-like region, a transparent electrode can be provided on the display side and the back side, and a driving device for applying a DC voltage or an AC voltage between the opposing electrodes can be used. . Here, the “display side” means the side on which the image is displayed, and the “back side” means the side opposite to the “display side” across the cellular region.

  Note that the driving method of the driving device may be passive driving or active driving using a thin transistor (TFT).

  The “light reflecting surface” may have a reflectance of 10% or more with respect to white light or light with a wavelength of 550 nm, but a reflectance of 50% or more is more preferable. As the “light reflecting surface”, for example, a surface coated with a metal or the like can be considered. The “reflection” may be specular reflection or diffuse reflection.

  It should be noted that an illumination device (backlight or the like) that emits white illumination light substantially uniformly to a plurality of cellular regions is further provided on the back side of the cellular region, and a light-transmissive display device that can obtain high brightness In addition, a reflector (white diffuser, etc.) that reflects the light incident on multiple cellular areas is further provided on the back side of the cellular area, and brightness is obtained using the irradiation light and natural light from the display side. Can be obtained as a light reflection type display device.

  Further, when the colored moving plate is located at the first position intersecting the display direction, the incident light is covered so as not to leak from the gap between the colored moving plate and the side portion of the partition wall. A mask may be provided on the display side or the back side of the partition wall.

  In the display device of the present invention, one cellular area may be displayed corresponding to one pixel, or a plurality of cellular areas may be displayed corresponding to one pixel. Good.

  The display device of the present invention can also be used as an optical shutter that turns on and off transmitted light.

  As a substrate material for forming the display side and the back side of the partition wall, a polymer substrate or the like can be used in addition to a glass substrate.

  A transparent electrode such as ITO, In2O3, SnO2, or ZnO can be used as the electrode. In the case of a reflective display device, a metal electrode made of Al, Ti, Pt, Cr, Ta, Cu, or an alloy material thereof can be used for the back side electrode.

  The insulating coating applied to the surface of the electrode may not be performed, but it is preferable to perform it when the material of the colored moving plate or the mask is conductive.

  There is no need to use a mask used to shield the leaked light from the side of the colored moving plate, but in order to achieve a blacker black luminance, the outer peripheral portion of the colored moving plate is viewed from the display side. It is preferable that it is covered with a mask.

  The material of the side portion of the partition wall may be a metal material or an insulating material, but is preferably a dry film resist that can be easily patterned.

  The material of the colored moving plate is preferably 10% or less of light transmittance, and preferably 1% or less in order to achieve high contrast. The size of the colored moving plate is preferably equal to or smaller than the size of one pixel.

  The transparent liquid preferably has a viscosity of 100 cps or less and has a boiling point of 100 ° C. or higher and a vapor pressure at 30 ° C. of 0.15 atm or lower so that the movement of the colored moving plate is not limited. Furthermore, it is preferable that the material is difficult to be electrolyzed by an electric field.

  According to the first display device of the present invention, in each of the cellular regions surrounded by the partition walls, the colored moving plate is moved by the action of an electric field in the liquid filling the cellular region, and the inside of the cellular region In the display device that displays an image by controlling the transmittance of light incident on the surface of the partition wall, the surface of the side portion of the partition wall is a light reflecting surface, so the colored moving plate is placed at a second position parallel to the display direction. When the so-called white display is performed in such a manner that the light is reflected by the light reflecting surface of the side portion of the partition wall, the amount of light in a direction non-parallel to the display direction can be increased. The viewing angle is improved and the visibility when observed from an oblique direction can be improved.

  According to the second display device of the present invention, in each of the cellular regions surrounded by the partition walls, the colored moving plate is moved by the action of an electric field in the liquid filling the cellular region, and the inside of the cellular region is In the display device that displays an image by controlling the transmittance of light incident on the color moving plate, at least a part of the main surface of the colored moving plate is a light reflecting surface. Therefore, the colored moving plate is parallel to the display direction. When performing so-called white display so as to be positioned at the position, the light is reflected by the light reflecting surface of the colored moving plate, and the amount of light in a direction non-parallel to the display direction can be increased. The viewing angle is improved, and the visibility when observed from an oblique direction can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a display device according to one embodiment (first embodiment) of the first display device of the present invention, and FIG. 2 is a side view thereof (viewed from the direction of arrow F in FIG. 1). Figure).

  A display device 101 according to the first embodiment of the present invention shown in FIG. 1 has a plurality of cellular regions 15a, 15b, 15c... Arranged along a plane orthogonal to the display direction (arrow Z direction in the figure). Hereinafter, a plurality of cellular regions 15a, 15b ... are collectively referred to as cellular regions 15), a transparent liquid 20M that fills each cellular region 15, a partition wall 10 that surrounds each cellular region 15, Colored moving plates 30a, 30b,... Arranged in the cellular region 15 and movable in the respective cellular regions 15 (hereinafter, the colored moving plates 30a, 30b,... Are collectively referred to as the colored moving plate 30). In addition to forming an electric field acting on the colored moving plate 30 and changing the electric field, the colored moving plate 30 is moved to a first position where the main surface intersects the display direction (in the present embodiment, the first position is perpendicular to the display direction). Position) and the table And a field forming means 41 to be positioned in a direction and a second position substantially parallel.

  Each of the cellular regions 15 is surrounded by a partition wall 10 whose display side portion and back side portion are transparent.

  The partition wall 10 is positioned on the display side portion 11 of the cell-like region 15 which is located on the display side (indicated by the arrow C1 in the drawing) and on the back side of the cellular region 15 (shown by the arrow C2 in the drawing). It is composed of a colorless and transparent back side portion 12 and an opaque side portion 13 located on the side surface side of the cellular region 15 (indicated by an arrow C3 in the figure). In addition, the metal coating r is given to the surface of the side part 13 of the partition wall 10, and the surface of the side part 13 is a light reflection surface.

  The colored moving plate 30 is opaque, and the colored moving plate 30 is made of a dielectric such as silicon oxide (SiO 2) or titanium oxide (TiO 2), or a metal such as aluminum (Al), titanium (Ti), or chromium (Cr). Alternatively, a material formed of a carbon plate, a polymer material, or the like is used, and among these materials, transparent materials are colored and rendered opaque. Opaque materials may be used as they are, but they may be used by coloring them. Here, the colored moving plate 30 is colored black.

  In addition, when each colored moving plate 30 is located at the first position, the shape when viewed from the display direction of the colored moving plate 30 and the shape when viewed from the display direction of the cellular region 15 are substantially the same. It is supposed to be.

  The electric field forming means 41 is a first electric field forming means (not shown) that always forms a first electric field in the direction perpendicular to the display direction with the same intensity for holding the colored moving plate 30 in the first position. ) And second electric field forming means for forming a second electric field in a direction parallel to the display direction for changing the colored moving plate 30 from the first position to the second position. The second electric field forming means is connected to the display side electrode 401 arranged in the display side portion 11, the back electrode 402 arranged in the back side portion 12, the display side electrode 401 and the back electrode 402, and these An AC power source that forms an AC electric field as a second electric field is applied by applying an AC voltage between the electrodes, and the intensity of the second electric field is controlled by controlling the AC voltage applied by the AC power source. can do.

  As the transparent liquid 20M, a colorless transparent liquid such as silicon oil or a silane coupling material is used.

  As described above, the colored moving plate 30 has a principal surface parallel to the direction of the electric field in an attempt to take the most stable posture in which the electrostatic energy in the system including the transparent liquid 20M and the colored moving plate 30 is minimized. Try to point in the direction. Therefore, in the state where the first electric field is formed by the first electric field forming means, no AC voltage is applied between the display side electrode 401 and the back electrode 402, and no second electric field is formed. The colored moving plate 30 is located at the first position by the action from the first electric field, and when an AC voltage is applied between the display side electrode 401 and the back electrode 402 to form the second electric field, The colored moving plate 30 is positioned at a position where the main surface is in the same direction as the direction of the combined electric field by the action of the combined electric field of the first electric field and the second electric field. Then, the AC voltage applied between the display-side electrode 401 and the back electrode exceeds a predetermined value, and the force acting on the second electric field greatly exceeds the force acting on the first electric field. When the acting force is negligible, the colored moving plate 30 is positioned at the second position.

  For example, in the case of the colored moving plate 30a in the cellular region 15a, no voltage is applied between the display side electrode 401a and the back electrode 402a in a state where the first electric field is formed (Va = 0V). ), Located in the first position. In the case of the colored moving plate 30b in the cellular region 15b, an AC voltage Vb exceeding a predetermined value is applied between the display side electrode 401b and the back electrode 402b in a state where the first electric field is formed. An AC electric field Eb is formed, and the force acting on the colored moving plate 30b by the second electric field greatly exceeds the force acting on the colored moving plate 30b by the first electric field, and the force acting on the colored moving plate 30b can be ignored. Is located at the second position.

  Therefore, according to the observation from the display side by illumination (reflective illumination) of the white light Lw from the display side (indicated by the arrow C1 in the figure), the colored moving plate 30a is observed in the cellular region 15a, and the cellular shape In the region 15b, the back side portion 12 is observed.

  Here, since the back side portion 12 is transparent, the illuminating device 51 that irradiates the illumination light Lv is disposed on the back side of the back side portion 12 (indicated by the arrow C2 in the figure). The black color of the moving plate 30a is visually recognized, and the white color of the illumination light Lv is visually recognized through the transparent back surface portion 12 in the cellular region 15b.

  At this time, when the so-called white display is performed with the colored moving plate 30b in the second position parallel to the display direction as in the cellular region 15b in FIG. Reflected by the metal coating r as a surface, the amount of light in a direction non-parallel to the display direction increases.

  As described above, according to the display device 101, when performing so-called white display, the amount of light in a direction non-parallel to the display direction increases, so that the viewing angle is improved and the visibility when observed from an oblique direction is improved. Can be improved.

  Note that the same effect can be obtained when a reflective plate (white diffuser or the like) is installed in place of the illumination device 51 to form a light reflection type display device.

  FIG. 3 shows a display device 102 according to one embodiment (second embodiment) of the second display device of the present invention. The same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  In the display device 102 according to the second embodiment of the present invention shown in FIG. 3, the metal coating r is applied to both surfaces of the colored moving plate 30 as at least a part of the main surface of the colored moving plate 30. Is a light reflecting surface.

  As described above, the colored moving plate 30 has a principal surface parallel to the direction of the electric field in an attempt to take the most stable posture in which the electrostatic energy in the system including the transparent liquid 20M and the colored moving plate 30 is minimized. Try to point in the direction. Therefore, in the state where the first electric field is formed by the first electric field forming means, no AC voltage is applied between the display side electrode 401 and the back electrode 402, and no second electric field is formed. The colored moving plate 30 is located at the first position by the action from the first electric field, and when an AC voltage is applied between the display side electrode 401 and the back electrode 402 to form the second electric field, The colored moving plate 30 is positioned at a position where the main surface is in the same direction as the direction of the combined electric field by the action of the combined electric field of the first electric field and the second electric field. Then, the AC voltage applied between the display-side electrode 401 and the back electrode exceeds a predetermined value, and the force acting on the second electric field greatly exceeds the force acting on the first electric field. When the acting force is negligible, the colored moving plate 30 is positioned at the second position.

  For example, in the case of the colored moving plate 30a in the cellular region 15a, no voltage is applied between the display side electrode 401a and the back electrode 402a in a state where the first electric field is formed (Va = 0V). ), Located in the first position. In the case of the colored moving plate 30b in the cellular region 15b, an AC voltage Vb exceeding a predetermined value is applied between the display side electrode 401b and the back electrode 402b in a state where the first electric field is formed. An AC electric field Eb is formed, and the force acting on the colored moving plate 30b by the second electric field greatly exceeds the force acting on the colored moving plate 30b by the first electric field, and the force acting on the colored moving plate 30b can be ignored. Is located at the second position.

  Therefore, according to the observation from the display side by illumination (reflective illumination) of the white light Lw from the display side (indicated by the arrow C1 in the figure), the colored moving plate 30a is observed in the cellular region 15a, and the cellular shape In the region 15b, the back side portion 12 is observed.

  Here, since the back side portion 12 is transparent, the illuminating device 51 that irradiates the white illumination light Lv on the back side of the back side portion 12 (indicated by the arrow C2 in the figure) is arranged, so that the cellular region 15a The light reflecting surface of the colored moving plate 30a is visually recognized, and the white color of the illumination light Lv is visually recognized through the transparent back side portion 12 in the cellular region 15b. The light reflection surface of the colored moving plate 30a in the cellular region 15a looks darker than the white color of the illumination light Lv when the light (for example, natural light) irradiated from the display side is weaker or less than the illumination light Lv. Therefore, even if both the main surfaces of the colored moving plate 30 are light reflecting surfaces, contrast can be obtained between so-called black display and white display, and the display device functions.

  At this time, when the so-called white display is performed with the colored moving plate 30b in the second position parallel to the display direction as in the cellular region 15b in FIG. 2, the light is the light of the colored moving plate 30b. Reflected by the metal coating r as the reflecting surface, the amount of light in a direction non-parallel to the display direction increases.

  As described above, according to the display device 102, when performing so-called white display, the amount of light in a direction non-parallel to the display direction increases, so that the viewing angle is similar to the display device 101 in the first embodiment. Can be improved, and visibility when observed from an oblique direction can be improved.

  FIG. 4 shows a display device 103 according to one embodiment (third embodiment) of the second display device of the present invention. The same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

  In the display device 103 according to another embodiment (third embodiment) of the second display device of the present invention shown in FIG. 4, the colored moving plate 30 is rotated within the cellular region 15 and the rotation axis of the colored moving plate 30. Is rotatably supported so as to be positioned at the end portion and the back side of the cellular region 15, and is on the back side when the colored moving plate 30 is in the first position among the main surfaces of the colored moving plate 30. A metal coating r is applied to one surface, and the surface is a light reflecting surface.

  As described above, the colored moving plate 30 has a principal surface parallel to the direction of the electric field in an attempt to take the most stable posture in which the electrostatic energy in the system including the transparent liquid 20M and the colored moving plate 30 is minimized. Try to point in the direction. Therefore, in the state where the first electric field is formed by the first electric field forming means, no AC voltage is applied between the display side electrode 401 and the back electrode 402, and no second electric field is formed. The colored moving plate 30 is located at the first position by the action from the first electric field, and when an AC voltage is applied between the display side electrode 401 and the back electrode 402 to form the second electric field, The colored moving plate 30 is positioned at a position where the main surface is in the same direction as the direction of the combined electric field by the action of the combined electric field of the first electric field and the second electric field. Then, the AC voltage applied between the display-side electrode 401 and the back electrode exceeds a predetermined value, and the force acting on the second electric field greatly exceeds the force acting on the first electric field. When the acting force is negligible, the colored moving plate 30 is positioned at the second position.

  For example, in the case of the colored moving plate 30a in the cellular region 15a, no voltage is applied between the display side electrode 401a and the back electrode 402a in a state where the first electric field is formed (Va = 0V). ), Located in the first position. However, since the rotation axis of the colored moving plate 30 a is located in the vicinity of the boundary line between the side portion 13 and the back side portion 12, the colored moving plate 30 a is in a position overlapping the back side portion 12. In the case of the colored moving plate 30b in the cellular region 15b, an AC voltage Vb exceeding a predetermined value is applied between the display side electrode 401b and the back electrode 402b in a state where the first electric field is formed. An AC electric field Eb is formed, and the force acting on the colored moving plate 30b by the second electric field greatly exceeds the force acting on the colored moving plate 30b by the first electric field, and the force acting on the colored moving plate 30b can be ignored. Is located at the second position. However, since the rotation shaft is located in the vicinity of the side portion 13, the colored moving plate 30 b moves to a position where it overlaps with the side portion 13.

  Therefore, according to observation from the display side in the display direction of the display device 103, the colored moving plate 30a is observed in the cellular region 15a, and the back side portion 12 is observed in the cellular region 15b.

  Here, by arranging the illuminating device 51 that irradiates the white illumination light Lv on the back side of the back side portion 12 (indicated by the arrow C2 in the figure), the black color of the colored moving plate 30a is changed in the cellular region 15a. The white color of the illumination light Lv is visually recognized through the transparent back side portion 12 in the cellular region 15b.

  At this time, when the so-called white display is performed with the colored moving plate 30b in the second position parallel to the display direction as in the cellular region 15b in FIG. 4, the light is the light of the colored moving plate 30b. Reflected by the metal coating r as the reflecting surface, the amount of light in a direction non-parallel to the display direction increases.

  As described above, according to the display device 103, when so-called white display is performed, the amount of light in a direction non-parallel to the display direction increases, so the display devices 101 and 102 in the first and second embodiments Similarly, the viewing angle is improved, and the visibility when observed from an oblique direction can be improved.

  Note that the same effect can be obtained when a white diffuser (reflector) is installed instead of the illumination device 51 to form a light reflective display device.

  In each of the above embodiments, an AC electric field is used as an electric field applied to the colored moving plate, but a DC electric field may be used.

  One pixel may be displayed so as to be held by one cell-like region, or one pixel may be displayed so as to be held by a plurality of cell-like regions (for example, four cell-like regions that are nearest to each other). May be.

The perspective view which shows schematic structure of the display apparatus by the 1st Embodiment of this invention. The side view which shows schematic structure of the display apparatus by the 1st Embodiment of this invention. The figure which shows schematic structure of the display apparatus by the 2nd Embodiment of this invention. The figure which shows schematic structure of the display apparatus by the 3rd Embodiment of this invention. Diagram showing the principle that white display is recognized as black display depending on the viewing angle The figure which shows the state in which the light which injects into a cellular region is absorbed by a partition wall or a colored moving board

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Partition wall 11 Display side part 12 Back side part 13 Side part 15 Cell-like area | region 20 Transparent liquid 30 Colored moving board 31 Hinge part 41 Electric field formation means 51 Illuminating device 101-103 Display apparatus 401 Display side electrode 402 Back electrode

Claims (2)

A plurality of cellular regions disposed along a plane orthogonal to the display direction;
A transparent liquid filling each of the cellular regions;
A partition wall that surrounds each of the cellular regions and at least the display side portion is transparent,
A colored moving plate arranged in each cellular region, movable in each cellular region;
An electric field acting on the colored moving plate is formed, and the electric field is changed to change the colored moving plate to a first position where the main surface intersects the display direction, and the main surface is substantially parallel to the display direction. Electric field forming means located at the second position,
A display device, wherein a surface of a side portion of the partition wall is a light reflecting surface. A plurality of cellular regions disposed along a plane orthogonal to the display direction;
A transparent liquid filling each of the cellular regions;
A partition wall that surrounds each of the cellular regions and at least the display side portion is transparent,
A colored moving plate arranged in each cellular region, movable in each cellular region;
An electric field acting on the colored moving plate is formed, and the electric field is changed to change the colored moving plate to a first position where the main surface intersects the display direction, and the main surface is substantially parallel to the display direction. Electric field forming means located at the second position,
At least a part of the main surface of the colored moving plate is a light reflecting surface.

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