JP5292861B2 - Electrophoretic display device driving method and electrophoretic display device - Google Patents

Abstract

The present invention provides a method for driving an electrophoretic display device which can display image at the front side and the back side and has the advantages of thinness and low cost and the electrophoretic display device thereof. The electrophoretic display device 10 is provided with an electrophoretic display layer between the element substrate and the opposite substrate which have light permeability, and furthermore a control device 50 and an acceleration sensor 52 are embedded in the second frame 11B of the display panel 11. The control device 50 determines the surface facing the upper side of the display panel 11 according to the inclination angle of the electrohoretic display device 10 detected by the acceleration sensor 52, and confirms the surface facing the upper side to a ''display surface'' for displaying image, etc. Furthermore, the control device 50 displays the image based on the displayed data on the display panel 11 at the condition that the ''display surface'' is the front surface, and displays the display data (reversal display data) which is obtained by reversing the left-and-right and black-and-white of the display data on the display panel 11 at the condition that the ''display surface'' is the back surface.

Description

  The present invention relates to an electrophoretic display device driving method and an electrophoretic display device.

  In recent years, non-luminous display devices having a flexible structure have been used as flexible display devices such as electronic paper. As one of such non-light emitting display devices, there is an electrophoretic display device using an electrophoretic phenomenon. Here, the electrophoresis phenomenon is, for example, a phenomenon in which fine particles migrate by Coulomb force when an electric field is applied to a dispersion system in which fine particles (electrophoretic particles) are dispersed in a liquid (dispersion medium).

  In electrophoretic display devices having flexibility, organic thin film transistors (organic TFTs) having flexibility are often used as thin film transistors. That is, an electrophoretic display device is constituted by, for example, an active matrix type circuit using an organic TFT as a pixel transistor.

  Therefore, a method of configuring an electrophoretic display device with an active matrix circuit has been proposed (Patent Document 1). Patent Document 1 discloses an electrophoretic display panel having a dispersion system in which electrophoretic particles are dispersed between an element substrate and a counter substrate. The element substrate includes pixel electrodes, scanning lines, data lines, and pixel TFTs. A common electrode is formed on the counter substrate. Further, an active matrix type electrophoretic display device which is inexpensive to manufacture by forming TFTs constituting a scanning line driving circuit and a data line driving circuit in a process common to the process of forming pixel TFTs on the element substrate. I am trying to manufacture.

However, both front and back sides of paper can be used for paper, but in the case of an electrophoretic display device, it is common to use only the surface for display.
Therefore, an electrophoretic display device that displays images and the like on both front and back surfaces has been proposed (Patent Document 2). Patent Document 2 discloses a first display unit having charged particles between a common substrate having a common drive electrode layer and a first display substrate having a first counter electrode layer serving as a ground electrode on the front surface of the display device. Is provided. In addition, on the back surface of the image display device, a second display portion having charged particles is provided between a common substrate shared with the front surface and a second display substrate having a second counter electrode layer which is a ground electrode. Then, by electrically switching the first or second counter electrode layer, an electric field is generated only in either the first or second display unit, and individual images or the like are respectively displayed on the first and second display units. By displaying, images and the like can be displayed on both the front and back surfaces of the electrophoretic display device.

JP 2002-169190 A Japanese Patent Laying-Open No. 2005-321732

  However, although Patent Document 2 realizes front and back double-sided display by sharing the common drive electrode layer between the first and second display units, a counter electrode and an electrophoretic display layer are required for each display unit. In addition, it is difficult to construct a thin electrophoretic display device and to reduce the manufacturing cost.

  The present invention has been made to solve the above problems, and provides a thin and inexpensive driving method for an electrophoretic display device capable of displaying an image or the like on both the front and back surfaces, and an electrophoretic display device. One of the purposes is to do. Another object of the present invention is to provide a thin electrophoretic display device capable of displaying both front and back surfaces.

  In order to solve the above problems, one electrophoretic display device of the present invention includes a transparent element substrate having a transparent pixel electrode, a transparent counter substrate having a transparent common electrode corresponding to the pixel electrode, An electrophoretic display layer sandwiched between the element substrate and the counter substrate; and a selection unit that selects one of the element substrate and the counter substrate as a display surface of the electrophoretic display layer. Including.

  Since the pixel electrode, the element substrate, the common electrode, and the counter substrate are transparent, any of the case where the element substrate is set as a display surface and the counter substrate is set as a display surface by selection of a selection unit. Even in this case, display can be performed with one electrophoretic display layer.

  In one electrophoretic display device according to the present invention, the selection unit displays the surface facing the upper side based on a signal from a sensor that detects the surface facing the upper side of the electrophoretic display device. It is preferable to select it as a surface.

Thereby, when using on a desk etc., it can be known automatically whether the display surface is the element substrate or the counter substrate.
In the electrophoretic display device of the present invention, the selection unit may select the display surface based on a signal from a switch that designates a display side of the electrophoretic display device. preferable.

Thereby, when using it except on a desk etc., the said display surface can be set to the side which a user asks.
In the electrophoretic display device of the present invention, it is preferable that the counter substrate is selected as the initial display surface for the display surface.

  If the display surface is different, it may occur that the display data is converted into one suitable for the display surface. However, by defining the initial display surface, the display data used as a reference can be changed. Can be set. In a general electrophoretic display device, the side where the counter electrode exists is often used as the display side. Therefore, it is easy to transfer data to the one electrophoretic display device of the present invention.

  In the electrophoretic display device of the present invention, a plurality of ordered display data is held, and the display surface rotates clockwise around a rotation axis parallel to the display surface, and the selection means When the display surface is switched, the display data ordered next to the display data displayed before the display surface is switched is displayed, and the display surface is reversed on the rotation axis parallel to the display surface. When the display surface is rotated by the selection means and the display surface is switched, it is preferable that the display data ordered before the display data displayed before the display surface is switched is displayed. .

  In order to solve the above-described problems, a driving method of an electrophoretic display device according to the present invention includes a transparent element substrate having a transparent pixel electrode and a transparent counter electrode having a transparent common electrode corresponding to the pixel electrode. A selection means for selecting one of the element substrate and the counter substrate as a display surface of the substrate, the electrophoretic display layer sandwiched between the element substrate and the counter substrate, and the display surface of the electrophoretic display layer And the display data is driven to the electrophoretic display layer so that the display is suitable for the display surface selected by the selection means.

  As one method in the driving method of one electrophoretic display device of the present invention, when the first display data to be displayed on the counter substrate is held in advance and the counter substrate is selected as the display surface Converts the first display data into the display data, and when the element substrate is selected as the display surface, converts the first display data into second display data for displaying on the element substrate. The display data is preferably used.

This facilitates the porting of data used in other electrophoretic display devices.
Further, as another method in the driving method of one electrophoretic display device of the present invention, the third display data when the counter substrate is the display surface, the element substrate is the display surface, and Fourth display data to be prepared is prepared in advance, and either the third data or the fourth data corresponding to the display surface selected by the selection means is selected and displayed. It is preferable to use data.

  As another method of driving the electrophoretic display device according to the present invention, the display data held in advance is displayed on either the counter substrate or the element substrate. It is display data, and the fifth display data has a tag indicating whether the display data has any of the substrates as a display surface, and the display surface selected by the selection means indicates the tag. When the display surface is the display surface, the fifth display data is used as the display data. When the display surface selected by the selection unit is not the display surface indicated by the tag, the fifth display data is displayed on the display surface. It is preferable to convert the display data into the display data.

  Alternatively, in the driving method of one electrophoretic display device of the present invention, the display data uses the same data when the counter substrate is a display surface and when the element substrate is a display surface. It is preferable that the order of the pixel electrodes is changed and driven by the display surface selected by the selection means.

This eliminates the need for data conversion.
In the driving method of an electrophoretic display device according to the present invention, a plurality of ordered display data are held, and the display surface rotates clockwise around a rotation axis parallel to the display surface, and the selection unit When the display surface is switched by this, the display data ordered next to the display data displayed before the display surface is switched is driven, and the display surface is rotated in parallel with the display surface. When the display surface is switched by the selection means by rotating counterclockwise in FIG. 5, the display data ordered before the display data displayed before the display surface is switched is driven. Is preferred.

  According to the electrophoretic display device and the electrophoretic display device driving method of the present invention, that is, the driving of the electrophoretic display device capable of suitably displaying images and the like on both the front and back surfaces of the thin and inexpensive electrophoretic display device. A method can be provided.

  In the electrophoretic display device and the driving method of the electrophoretic display device of the present invention, it is preferable that the display data is changed to other display data when it is determined that the display surface is switched based on detection of the sensor. It is.

  According to the electrophoretic display device and the electrophoretic display device driving method of the present invention, the display data is changed when the “display surface” is switched. Accordingly, since the image displayed on the “display surface” is changed by switching the “display surface” of the electrophoretic display device determined based on the sensor, the image of the electrophoretic display device can be operated by turning the paper. Can be changed. As a result, the application of the electrophoretic display device as an electronic paper or an electronic book can be expanded.

  In the electrophoretic display device according to the aspect of the invention, the display data may be converted into left and right and color-inverted display data for the display surface when the display surface is not on the predetermined substrate side. Is preferred.

  According to this electrophoretic display device, when the “display surface” is not on a predetermined substrate side, the display data is converted into display data by inverting the left and right colors of the display data. Therefore, a suitable image can be displayed on the substrate side other than the predetermined substrate side on which the suitable image is not displayed with the display data as it is, based on the converted display data. As a result, the application of the electrophoretic display device as an electronic paper or an electronic book can be expanded.

In the electrophoretic display device of the present invention, the element substrate and the counter substrate preferably have the same light transmittance.
According to this electrophoretic display device, the light transmittance of the element substrate and the counter substrate is the same. Therefore, regardless of which substrate side is determined as the “display surface” and an image is displayed, the same light transmittance is maintained. Will display the image. Accordingly, it is possible to reduce the difference in the image, for example, the difference in light and shade, depending on whether the image is displayed on the element substrate side or the counter substrate side.

The sensor used in the electrophoretic display device of the present invention may be an acceleration sensor, for example.
Whether the rotation direction of the electrophoretic display device is “clockwise” or “counterclockwise” by the acceleration sensor, or “upper” can be easily detected and determined by the control device. it can. As a result, it is possible to easily specify the “display surface” of the electrophoretic display device, and it is possible to cope with various rotation patterns of the electrophoretic display device.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a method for driving an electrophoretic display device and an electrophoretic display device according to the present invention will be described with reference to the drawings.
1 and 2 are plan views of the entire electrophoretic display device (display device) 10.

  As shown in FIGS. 1 and 2, the display device 10 includes an electrophoretic display panel (display panel) 11. The display device 10 has a first frame portion 11 </ b> A below the display panel 11. Has a second frame portion 11B.

  As shown in FIG. 2, the first frame portion 11 </ b> A is provided with four operation buttons 111 to 114. Each of the operation buttons 111 to 114 is thin and flexible, and is formed of, for example, a membrane switch, a sheet-like key switch, a pressure sensor, etc., and responds to an operation from either the front or back of the display panel 11. Can be done. The second frame portion 11B is provided with a storage battery (not shown), an external connection terminal (not shown), or the like as a drive power source for the display device 10.

FIG. 3 is a cross-sectional view of the display panel 11 taken along the line 3-3.
In FIG. 3, the display panel 11 includes an element substrate 12 and a counter substrate 13, and an electrophoretic display layer 14 is disposed between the element substrate 12 and the counter substrate 13. Further, a front surface 13a is provided on the surface (upper side in FIG. 3) of the counter substrate 13, and a back surface 12a is provided on the surface (lower side in FIG. 3) of the element substrate 12. That is, the electrophoretic display layer 14 is viewed through the counter substrate 13 from the A direction (front surface 13a side) and the element substrate 12 from the B direction (back surface 12a side).

  As shown in FIG. 3, the element substrate 12 includes a back substrate 15 having flexibility and light transmission, and an element formation layer 16 is formed on one surface (the upper side in FIG. 3). The back substrate 15 is formed of a thermoplastic resin or a thermosetting resin material excellent in flexibility, light transmittance, elasticity, and the like, for example, polyethylene terephthalate, polycarbonate, polyimide, polyethylene, and the like. In addition, a plurality of conductive layers and insulating layers are formed in the element forming layer 16, and for example, an organic transistor Tr (see FIG. 4), a pixel electrode, and various wirings are formed. The conductive layer, particularly the pixel electrode, is formed of a light-transmitting conductive material, for example, an indium tin oxide or the like, or an electronically conductive polymer such as polyaniline. The insulating layer is also formed of a light transmissive material. In addition, the thickness of the wiring formed of non-light-transmitting members is set to several μm (micrometers), or the thickness is set to 10 nm (nanometers), and the reduction of light transmittance is suppressed. It has come to be.

  In the present embodiment, the p-type channel organic transistor Tr will be described. However, the organic transistor may have an n-type channel or other type of organic transistor.

  As shown in FIG. 4, the organic transistor Tr is a field effect type in which an insulating layer, an electrode, and an organic semiconductor layer that form the element forming layer 16 are laminated on the upper surface of the back substrate 15 in a predetermined order. It is formed as a transistor. If the electrode is a conductive material and a material with low transparency, for example, a metal such as gold, copper, or aluminum, the film thickness is desirably 100 nm or less. When it is 100 nm or more, the transmittance of visible light is lowered, and one display characteristic is lowered. Similarly, for an electroconductive polymer such as polyaniline, a film thickness of 10 μm or less is desirable. When it is 10 μm or more, the transmittance of visible light is lowered, and one display characteristic is lowered. In addition, an oxide having transparency such as indium tin oxide or indium zinc oxide is preferable because it has high visible light transmittance. On the other hand, the insulating layer is made of an insulating material such as epoxy resin, ester resin, polyparaxylene, and derivatives thereof, polyvinyl phenol, acrylic resin represented by polymethyl methacrylate, polyimide, polystyrene, polyvinyl alcohol, polyvinyl. It is formed from one material of acetate or the like, or a material obtained by combining two or more of these materials. Among them, a material that does not have an absorption wavelength in the visible light region or has a large transmission coefficient is preferable. The organic semiconductor layer is, for example, naphthalene, anthracene, tetracene, pentacene, hexacene, phthalocyanine, perylene, hydrazone, triphenylmethane, diphenylmethane, stilbene, arylvinyl, pyrazoline, triphenylamine, triarylamine, oligothiophene, phthalocyanine Or low molecular organic semiconductor materials such as derivatives thereof, poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polythiophene, polyhexylthiophene, poly (p-phenylenevinylene), polytinylenevinylene, polyarylamine , Pyrene formaldehyde resin, ethylcarbazole formaldehyde resin, fluorene-bithiophene copolymer, fluorene-arylamine copolymer or the like Mentioned organic semiconductor material of a polymer such as a derivative, can be used singly or in combination of two or more of them. Furthermore, a material that does not have an absorption wavelength in the visible light region or has a large transmission coefficient is preferable.

That is, the element substrate 12 is formed so as to have a predetermined light transmittance such that a range corresponding to the pixel electrode has a predetermined aperture ratio.
The counter substrate 13 includes a transparent substrate 17 that is also flexible and light transmissive, and a common electrode 18 is formed on one surface (lower side in FIG. 3). The transparent substrate 17 is formed of a thermoplastic resin or a thermosetting resin material excellent in flexibility, light transmittance, elasticity, and the like, for example, polyethylene terephthalate, polycarbonate, polyimide, polyethylene, and the like. The common electrode 18 is formed of the same material as the above-described electrode.

  In this embodiment, the transparent substrate 17 is formed with the same thickness by the same member as the back substrate 15, and the common electrode 18 is formed with the same thickness as the element forming layer 16. 12 and the counter substrate 13 are formed so that the light transmittances thereof are close to each other. Alternatively, the thickness of the substrate and the thickness of the correlation insulating layer are adjusted so that the light transmittance in the visible region on both sides is the same.

  Note that a light-shielding black matrix covering the organic transistor may be formed in the insulating layer of the element formation layer 16. Specifically, a grid-like black matrix (not shown) having the pixel electrode 26 in FIG. 6 as an opening is formed over all pixels (display area), and the organic transistor Tr overlaps with the black matrix in plan view. Arrange so that. For example, the organic transistor Tr is disposed outside the pixel electrode in the vicinity of the intersection of the data line Lxm and the scanning line Lyn.

  According to this configuration, it is possible to prevent light incident from the back substrate 15 side from being applied to the organic transistor Tr, and the operation of the transistor can be stabilized. A black matrix may also be formed on the transparent substrate 17. As described above, since the black matrix is formed so as to surround each pixel (electrode), it has an effect of making the gradation of each pixel stand out, and the contrast can be increased. Further, the display quality on the front side and the back side can be made uniform.

  The electrophoretic display layer 14 includes a large number of microcapsules 20 integrated by a binder 19. As shown in FIG. 4, an electrophoretic dispersion medium 34 as a dispersion system and electrophoretic particles 35 are enclosed in the microcapsule 20. The electrophoretic particles 35 include white particles 35 w that are positively or negatively charged, and black particles 35 b that are charged to a polarity different from that of the white particles 35 w, and each corresponds to the direction of the electric field applied to the microcapsule 20. The electrophoretic dispersion medium 34 is migrated.

  The microcapsules 20 are made of, for example, an gum arabic / gelatin compound, a urethane compound, or the like. The electrophoretic dispersion medium 34 is made of, for example, water, methanol, ethanol, or the like. In addition, the electrophoretic particles 35 are formed of, for example, aniline black, carbon black, titanium dioxide, or the like.

  In other words, in the present embodiment, the image displayed on the electrophoretic display layer 14 by the electrophoretic particles 35 is the same light whether it passes through the counter substrate 13 from the A direction or the element substrate 12 from the B direction. It is displayed under the transmittance.

  On the other hand, in the element substrate 12, as shown in FIG. 2, a scanning line driving circuit 23 is provided at a position corresponding to the first frame portion 11A, and at a position corresponding to the second frame portion 11B. , A display control circuit 22, a data line driving circuit 24, a control device 50, and an acceleration sensor 52 are provided.

FIG. 5 is a diagram illustrating a circuit configuration in a state in which the display device 10 illustrated in FIG. 2 is rotated 90 degrees in the clockwise direction, that is, in a state where the second frame portion 11B is on the upper side.
As shown in FIG. 5, the element substrate 12 has n scanning lines Ly1, Ly2,..., Lyn (n is a natural number) arrayed over substantially the entire width in the horizontal direction (vertical direction in FIG. 2). M data lines Lx1, Lx2,..., Lxm (m is a natural number) are arranged in an array extending over substantially the entire width in the vertical direction (left and right direction in FIG. 2).

  Pixels 26 connected to the corresponding scanning lines Ly1 to Lyn and the data lines Lx1 to Lxm are arranged at respective positions where the scanning lines Ly1 to Lyn and the data lines Lx1 to Lxm intersect. That is, a plurality of pixels 26 are arranged in a matrix on the element substrate 12. Each pixel 26 includes a control element such as an organic transistor Tr and a light-transmissive pixel electrode 27 (see FIG. 6) made of a transparent conductive film.

  FIG. 6 is an equivalent circuit of the pixel 26 formed corresponding to the intersection of the “mth” data line Lxm and the “nth” scanning line Lyn. The pixel 26 includes one organic transistor Tr, an electrophoretic display layer 14 having a size corresponding to the pixel electrode 27, and a common electrode 18.

  The organic transistor Tr has a gate electrode 46 connected to the “nth” scanning line Lyn and a source electrode 42 connected to the “mth” data line Lxm. The drain electrode 43 of the organic transistor Tr is connected to the pixel electrode 27. A common electrode 18 is formed at a position facing the pixel electrode 27 via the electrophoretic display layer 14. The common electrode 18 is connected to the common terminal COM.

  As shown in FIG. 7, an acceleration sensor 52 is provided in the second frame portion 11 </ b> B of the display panel 11. The acceleration sensor 52 has an X direction detection axis 52x whose direction matches the X direction of the display panel 11, a Y direction detection axis 52y whose direction matches the Y direction of the display panel 11, and a direction that matches the Z direction of the display panel 11. A Z-direction detection axis 52z is provided.

  More specifically, as shown in FIGS. 8A and 8B, the X-direction detection axis 52x is an axis for detecting an inclination angle ΔX with respect to the horizontal line Lx. The Y direction detection axis 52y is an axis for detecting the inclination angle ΔY with respect to the horizontal line Ly. The Z direction detection axis 52z is an axis for detecting the tilt angle ΔZ with respect to the antigravity direction -g.

  The inclination angle ΔX is “0 degrees” when the X direction detection axis 52x is parallel to the horizontal line Lx, “−90 degrees” when the X direction detection axis 52x is parallel to the gravitational direction g, and It is detected as “90 degrees”.

  In addition, the tilt angle ΔY coincides with the antigravity direction −g, “0 degrees” when the Y direction detection axis 52y is parallel to the horizontal line Ly, “−90 degrees” when the Y direction detection axis 52y coincides with the gravity direction g. In this case, “90 degrees” is detected.

  Further, the inclination angle ΔZ is “0 degree” when the Z direction detection axis 52z coincides with the antigravity direction −g, “90 degrees” when horizontal, and “180” when coincident with the gravity direction g. "Degree".

Next, the electrical configuration of the electrophoretic display device 10 configured as described above will be described with reference to FIG.
In FIG. 9, a control device 50 as selection means includes a CPU, a ROM, a RAM, and the like. The control device 50 controls the display operation of the display panel 11 through the display control circuit 22 in accordance with various data and various programs stored in the ROM, RAM, and the like.

An input device 51, an acceleration sensor 52, operation buttons 111 to 114 as switches, and a display control circuit 22 are connected to the control device 50.
The input device 51 is electrically connected to the control device 50 through an external connection terminal. The input device 51 is detachably connected to the control device 50 (display device 10), and is electrically connected when necessary. The input device 51 inputs image data BD, various programs, and the like to the control device 50 and supplies power for charging the storage battery to the storage battery. The image data BD is, for example, data for one book, and is generated by combining images corresponding to the display contents for all the pages together with information on the separation for each page.

  The control device 50 stores the input image data BD in the RAM. In addition, the control device 50 selects a predetermined page to be displayed on the display panel 11, and displays the display data PD constituting the first display data for one page divided from the image data BD based on the page separation information. It is generated and input to the display control circuit 22. In the present embodiment, the front surface 13a of the display device 10 is set as a reference display surface (initial display surface), and the display data PD displays characters and the like on the front surface 13a as the initial display surface. It is the generated data.

For example, based on the display data PD, as shown in FIG. 10A, the character (image) “ABC” for one page is displayed on the front surface 13 a side of the display device 10. At this time, since the element substrate 12 is transparent, an inverted character (inverted image) obtained by inverting the character (image) “ABC” is also displayed on the back surface 12a side.
In other words, a positive image “ABC” is displayed on the front surface 13a side, and an inverted negative image “ABC” is displayed on the rear surface 12a side.

  Since the display device 10 is a reflective display device, the display on the back surface 12a side is not observed when viewed from the front surface 13a side. The opposite is also true. For this purpose, it is desirable that the electrophoretic dispersion medium 34 described with reference to FIG. 4 is an intermediate color (for example, gray) between white and black and semi-translucent. According to this configuration, for example, when observing from the front surface 13a side, it is possible to reduce the influence of light incident from the back surface 12a. Also, gradation display can be performed. Specifically, for example, when observed from the front surface 13a side, when white particles are in close contact with the common electrode 18, "white" is displayed, and the white particles are transmitted through the electrophoretic dispersion medium 34 as the distance from the common electrode increases. Since the light reflected by the particles is gradually attenuated, the color becomes “light gray”. When the white particles come to the middle of the thickness of the electrophoretic display layer, the color tone of the dispersion medium becomes “gray”. Further, when the white particles further sink, that is, approach the element substrate 12 side, “dark gray” is obtained. At this time, the black particles approach the common electrode 18 side instead of the white particles, and when the white particles completely sink and adhere to the element forming layer 16, the black particles adhere to the common electrode 18. Therefore, “black” is observed on the front surface 13a side.

  As described above, according to the electrophoretic display device 10 of the present application, by controlling the potential difference applied between the common electrode 18 and the element forming layer 16 (pixel electrode 26), electrophoretic display of white particles and black particles. Gray scale display can be performed by adjusting the position of the layer in the thickness direction.

  The letters “ABC” displayed on the front surface 13a side are as shown in FIG. 10A because the black particles 35b of the electrophoretic particles 35 dispersed in the electrophoretic dispersion medium 34 gather on the front surface 13a side. Are displayed in black. On the other hand, the reversed characters displayed on the back surface 12a side of the display device 10 are displayed in white as shown in FIG. 10B because the white particles 35w of the electrophoretic particles 35 gather on the back surface 12a. .

In the present embodiment, the surface side on which the desired image is correctly displayed on the front surface 13a side or the back surface 12a side is referred to as a “display surface”.
That is, when the “display surface” is the front surface 13a side, the control device 50 converts the display data PD into display data PD for one page read from the image data BD. On the other hand, when the “display surface” is on the back surface 12a side, the display data PD is read from the image data BD, and the second and right and black and white of the display data PD are both inverted. Are generated as display data PD (inverted display data) constituting the display data.

  An X-axis angle signal AX indicating an inclination angle ΔX, a Y-axis angle signal AY indicating an inclination angle ΔY, and a Z-axis angle signal AZ indicating an inclination angle ΔZ are input to the control device 50 from the acceleration sensor 52. .

  The control device 50 receives the Z-axis angle signal AZ from the acceleration sensor 52, and when the Z-axis angle signal AZ is a signal indicating an angle “0 degree” or more and less than “90 degrees”, the front surface 13a of the display panel 11 is displayed. Is determined to be facing up. The control device 50 receives the Z-axis angle signal AZ from the acceleration sensor 52, and when the Z-axis angle signal AZ is a signal indicating an angle of “90 degrees” or more and “180 degrees”, It determines with the back surface 12a facing up. Then, the controller 50 determines whether one of the front surface 13a and the rear surface 12a is facing upward after initial setting or power-on, and identifies it as a “display surface” for displaying an image or the like. It is supposed to be.

  That is, when the Z-axis angle signal AZ indicates an angle “0 degree” or more and less than “90 degrees”, the control device 50 detects the front surface 13a side as the “display surface”, and the Z-axis angle signal AZ has the angle “90”. In the case of indicating from “degree” to “180 degrees”, the rear surface 12a side is detected as the “display surface”.

  Further, as shown in FIG. 11A, the control device 50 indicates that the display device 10 has rotated in the direction indicated by the arrow 60 with the center line C1 as the center of rotation, that is, rotated clockwise. When detected from the shaft angle signal AX, it is determined that the display device 10 has “forwardly rotated”. For example, when the “display surface” is on the front surface 13a side, the control device 50 rotates the tilt angle ΔX from “0 degrees” through “90 degrees” toward “180 degrees” or “display surface” In the case of the back surface 12a side, a rotation in which the inclination angle ΔX passes from “180 degrees” to “−90 degrees” and goes to “0 degrees” is determined as “forward rotation”. Further, as shown in FIG. 11B, the control device 50 indicates that the display device 10 has rotated in the direction indicated by the arrow 61 with the center line C1 as the rotation center, that is, has rotated in the counterclockwise direction. When detected from the X-axis angle signal AX, it is determined that the display device 10 has “reversely rotated”. For example, when the “display surface” is on the front surface 13a side, the controller 50 rotates the tilt angle ΔX from “0 degrees” through “−90 degrees” toward “180 degrees” or “display surface”. Is the rear surface 12a side, the case where the inclination angle ΔX passes from “180 degrees” to “90 degrees” toward “0 degrees” is determined as “reverse rotation”.

  Then, when the display device 10 “forward-rotates”, the control device 50 determines to advance the page next, and changes the data read from the image data BD to the display data PD for the next page. It has become. Further, when the display device 10 “reversely rotates”, the control device 50 determines to return the page, and changes the data read from the image data BD to the display data PD for the previous page. Yes.

  By the way, the control device 50 reads the first page as a page to be displayed on the display panel 11 after the power is turned on, immediately after the new image data BD is stored in the RAM, and selects the same page as the previous time otherwise. It is supposed to be.

The control device 50 inputs button signals B1 to B4 output based on the ON operation from the operation buttons 111 to 114.
The control device 50 is configured to execute functions corresponding to the button signals B1 to B4 in response to the button signals B1 to B4. Further, the use of the button signals B1 to B4 from the operation buttons 111 to 114 is changed according to data or programs stored in the RAM or ROM. In this embodiment, the operation button 111 is a “power” button for turning on / off the power, the operation button 112 is a “previous page” button for moving to the previous page, and the operation button 113 is moved to the next page “next” The operation buttons 114 are assigned to “page display” buttons and “display screen switching” buttons for switching “display screen”.
In addition to the above buttons, an operation button for switching the display positive / negative and an operation button for adjusting the display gradation may be provided.

  The display control circuit 22 is electrically connected to the scanning line driving circuit 23 and the data line driving circuit 24. The display control circuit 22 outputs a vertical synchronization signal SC to the scanning line driving circuit 23 and a data timing signal VD to the data line driving circuit 24. Further, the display data PD for one page is received from the control device 50, and the display data PD is supplied to the data line driving circuit 24 in synchronization with the data timing signal VD. An image or the like is displayed on the display panel 11.

  Based on the vertical synchronization signal SC transmitted from the display control circuit 22, the scanning line driving circuit 23 converts one scanning line out of the n scanning lines Lyn provided on the element substrate 12 to Ly 1 and Ly 2. ,..., Lyn-1, and Lyn are selected in this order. The scanning line driving circuit 23 outputs scanning signals SC1 to SCn (n is a natural number) corresponding to the selected scanning line. The scanning signals SC1 to SCn control the timing at which the data signals VD1 to VDm output from the data line driving circuit 24 are supplied to the pixels 26 on the selected scanning line.

  The data line driving circuit 24 generates data signals VD1 to VDm corresponding to the display data PD and supplies the data signals VD1 to VDm to the respective pixels 26 via the corresponding data lines Lx1 to Lxm. That is, the organic transistors Tr of the respective pixels 26 selected by the scanning signals SC1 to SCn from the scanning line driving circuit 23 are set to the ON state, and the data signals VD1 to VDm supplied to the respective pixels 26 are the organic transistors. It is supplied to the pixel electrode 27 through Tr. That is, an electric field based on the voltages of the data signals VD1 to VDm is generated between the pixel electrode 27 and the common electrode 18 facing each other through the electrophoretic display layer 14. Then, based on the electric field generated between the pixel electrode 27 and the common electrode 18, the pixel electrode 27 or the common electrode 18 in which the white particles 35w and the black particles 35b as the electrophoretic particles 35 have potentials corresponding to the respective charges. Thus, an image or the like based on white or black is displayed on the surface of the display panel 11.

Next, the operation of the electrophoretic display device 10 configured as described above will be described with reference to FIGS.
Here, for convenience of explanation, the control device 50 of the display device 10 stores new image data BD including images for a plurality of pages in the RAM, and the image of the first page of the image data BD is black on a white background. It is assumed that the positive image showing the characters “ABC” and the image on the second page are the positive images showing the characters “DEF” black on a white background.

  First, the display device 10 is turned on by operating the operation button 111 as a “power” button. Then, the control device 50 determines that the front surface 13a side of the display panel 11 facing upward (ceiling side) is the “display surface”, and displays “ABC” on the front surface 13a side as shown in FIG. Display the image.

  Next, the display device 10 is rotated in the direction indicated by the arrow 60 with the center line C1 as the center of rotation. Then, the control device 50 determines that the display device 10 is “forward rotated” from the Z-axis angle signal AZ input from the acceleration sensor 52.

  When it is determined that the display device 10 has “forwardly rotated” and the “display surface” has been switched to the back surface 12a side, the control device 50 uses the display data PD of the second page from the image data BD to advance the page. read out. Since the “display surface” is on the back surface 12a side, the control device 50 generates and displays display data PD (inverted display data) that inverts both the left and right and black and white images based on the display data PD of the second page. Input to the control circuit 22. Then, on the back surface 12a side that is the “display surface” of the display device 10, an image with black “DEF” displayed on a white background is displayed as shown in FIG.

  Similarly, the control device 50 reads the display data PD of the next page from the image data BD when the display device 10 is “forward-rotated” and the “display surface” is switched to the front surface 13a side. The display data PD is input to the display control circuit 22. When the display device 10 is “forward rotated” and the “display surface” is on the back surface 12a side, the control device 50 reads the display data PD of the next page from the image data BD, and displays the display data. Display data PD (inverted display data) obtained by inverting both the left and right sides of the PD image and black and white is generated and input to the display control circuit 22. In this way, images of each page can be displayed sequentially and sequentially on the display device 10.

  On the other hand, when “DEF”, which is the image of the second page, is displayed on the back surface 12a as shown in FIG. 11B, the display device 10 is in the direction indicated by the arrow 61 with the center line C1 as the rotation center. Rotate to Then, the control device 50 detects that the display device 10 is “reversely rotated” from the Z-axis angle signal AZ input from the acceleration sensor 52.

  When it is determined that the display device 10 is “reversely rotated” and the “display surface” is switched to the front surface 13a side, the control device 50 reads the display data PD of the first page from the image data BD to return the page. Then, since the “display surface” is the front surface 13a, the control device 50 inputs the display data PD of the first page to the display control circuit 22 as it is. Then, on the front surface 13a that has become the “display surface” of the display device 10, an image with black “ABC” characters displayed on a white background is displayed as shown in FIG.

  Similarly, when the display device 10 is “reversely rotated” and the “display surface” is switched to the front surface 13a, the control device 50 reads and displays the display data PD of the previous page from the image data BD. Input to the control circuit 22. Further, when the display device 10 is “reversely rotated” and the “display surface” is the back surface 12a, the control device 50 reads the display data PD of the previous page from the image data BD and reads the read display. Based on the data PD, display data PD (inverted display data) in which both the left and right sides of the image and black and white are inverted is generated and input to the display control circuit 22. In this way, the image of the previous page of each page can be continuously displayed on the display device 10.

  Accordingly, by rotating the display device 10 in the “forward rotation” or “reverse rotation”, an image can be displayed on the front display 13a side or the “display surface” on the rear surface 12a so as to advance or return the page. it can. As a result, it is possible to provide a thin and inexpensive driving method for an electrophoretic display device capable of displaying images and the like on both front and back surfaces, and an electrophoretic display device.

As described above, according to the driving method of the electrophoretic display device and the electrophoretic display device according to the present embodiment, the effects listed below can be obtained.
(1) In the present embodiment, the element substrate 12 and the counter substrate 13 are formed of a light transmissive member, and the element formation layer 16 is also formed of a light transmissive member. Therefore, in addition to the front surface 13a side of the display panel 11, the image displayed on the electrophoretic display layer 14 can also be viewed from the back surface 12a side which is the surface of the element substrate 12.
Furthermore, since the electrophoretic display device 10 according to the present embodiment is configured to sandwich one electrophoretic display layer 14 between the element substrate 12 and the counter substrate 13, two electrophoretic display layers are provided for each of the front and back display units. One (two layers) can be made thinner than the conventional electrophoretic display device.

  (2) In the present embodiment, the transparent substrate 17 is formed with the same thickness by the same member as the back substrate 15, and the common electrode 18 is formed with the same thickness as the element forming layer 16, The counter substrate 13 was formed so that the light transmittance was close. Therefore, an image or the like displayed on the electrophoretic display layer 14 is displayed under the same light transmittance both through the counter substrate 13 from the A direction and through the element substrate 12 from the B direction. As a result, the same image can be displayed with the same light transmittance whether the "display surface" is displayed on the front surface 13a side or the "display surface" is displayed on the back surface 12a side. That is, it is possible to reduce the difference in the image, for example, the difference in light and shade, depending on whether the image is displayed on the front 13a side or the back surface 12a side.

(3) In the present embodiment, the image data BD is, for example, data for one book. Therefore, the display device 10 can be made to correspond to one book.
(4) In the present embodiment, when the “display surface” is the front surface 13a of the display panel 11, the control device 50 generates the display data PD from the display data PD selected from the image data BD. When the “display surface” is the back surface 12a of the display panel 11, display data PD (reversed display data) obtained by inverting both the left and right and black and white of the display data PD read from the image data BD is displayed. Generated. Therefore, the display device 10 can display an image based on the image data BD on both the front surface 13a and the back surface 12a.

  (5) In the present embodiment, the display device 10 includes the acceleration sensor 52. Accordingly, the inclination angle ΔX, the inclination angle ΔY, and the inclination angle ΔZ of the display device 10 can be easily detected by the acceleration sensor 52, and the rotation direction of the display device 10 is easily determined based on the detection. be able to.

  (6) In the present embodiment, it is detected from the acceleration sensor 52 whether the display device 10 has “forwardly rotated” or “reversely rotated”. Accordingly, the page can be advanced by rotating the display device 10 in the “forward rotation”, and the page can be returned by rotating in the reverse direction. As a result, the display device 10 can change an image to be displayed by an operation such as turning a book or a pamphlet.

  (7) In this embodiment, the operation button 112 is assigned to the button for moving to the previous page, the operation button 113 is assigned to the button for moving to the next page, and the operation button 114 is assigned to the button for switching the display surface. Therefore, the display can be manually adjusted in accordance with the posture referring to the display device 10.

(Other embodiments)
In the above embodiment, it is detected from the acceleration sensor 52 whether the display device 10 has “forwardly rotated” or “reversely rotated”. However, the present invention is not limited to this, and it may be detected from the acceleration sensor 52 that the display device 10 has “laterally rotated” around the point C <b> 2. For example, as shown in FIG. 12, when “horizontal rotation” is performed by 90 degrees around the point C2, it is detected that the “display surface” is horizontally long and an image for two pages is displayed. May be. In addition, when the display device 10 detects that “horizontal rotation” is performed by 180 degrees about the point C2 as the rotation center, the upper and lower sides of the displayed image may be switched.

  In the above embodiment, the image data BD is input from the input device 51 to the control device 50. However, the present invention is not limited to this, and a wireless communication function may be added to the control device 50 to transfer the image data BD by wireless communication. Further, a connection terminal of a storage device such as a memory card may be provided in the control device 50 so that the image data BD is supplied from the memory card or the like.

  In the above embodiment, the display device 10 is supplied with power from a built-in storage battery, but may be supplied with power from an external power source. If it does so, the display apparatus 10 can be used in the place with a power supply irrespective of the residual amount of electricity of a storage battery. Moreover, the display device 10 can be reduced in weight by removing the storage battery from the display device 10.

  In the above embodiment, the operation buttons 111 to 114 are provided on the first frame portion 11A, but the operation buttons 111 to 114 are not necessarily required. Further, the operation buttons 111 to 114 may be replaced with alternative ones. For example, a touch sensor is provided on the surface of the display device 10, and the touch detected by the touch sensor is compared with the image displayed on the display device 10 to detect that a specific operation has been performed. May be.

In the above embodiment, the acceleration sensor 52 is provided in the second frame portion 11B. However, if the position where the acceleration sensor 52 is provided is a place that does not hinder display on the front and back surfaces, any part of the electrophoretic display device 10 is provided. But you can.
In the above embodiment, the “display surface” is detected by the acceleration sensor 52. However, the present invention is not limited to this, and the “display surface” may be detected by an optical sensor or a touch sensor. When an optical sensor is used, the “display surface” can be detected based on the detected light intensity. When the touch sensor is used, the “display surface” can be detected from the difference in the gripped area.

  In the above embodiment, the image for one page is displayed on the display device 10, but the image for a plurality of pages, for example, the image for four pages, etc. may be displayed on the display device 10. .

  In the above embodiment, the display device 10 is white and black. However, the present invention is not limited thereto, and white and black may be other colors or may be displayed with a plurality of gradations. In addition, a color filter can be provided between the common electrode 18 and the transparent substrate 17 and between the element forming layer 16 and the element substrate 12 to perform color display on both the front and back surfaces. In this case, three pixels each having red, green, and blue color filters are configured as one color pixel.

  In the above embodiment, the display device 10 is electronic paper, but may be used as an electronic book 70 as shown in FIG. In this case, a plurality of electrophoretic display devices 10 </ b> A are bound to a ring 72 provided in the binder 71. Each electrophoretic display device 10 </ b> A may be supplied with image data BD or supplied with power through a ring 72.

In the above embodiment, the first frame portion 11A and the second frame portion 11B are provided, but the first frame portion 11A and the second frame portion 11B may be omitted.
In the above embodiment, the back substrate 15 and the transparent substrate 17 are made of the same member and the same thickness, and the element forming layer 16 and the common electrode 18 are made the same thickness. However, not limited to this, the members are not the same, and the thicknesses may not be the same. In short, it is only necessary that the light transmittance of the element substrate 12 and the counter substrate 13 can be made the same. Further, when the light transmittance of the element substrate 12 and the counter substrate 13 is different, a member or the like for matching the light transmittance may be added to the higher light transmittance.

  In the above embodiment, the image data BD includes one display data PD for each page. However, the present invention is not limited to this, and the image data BD includes, for one page, third display data in which the counter substrate 13 side is the “display surface” and fourth element in which the element substrate 12 side is the “display surface”. Display data may be included.

  In the above embodiment, the image data BD includes the display data PD with the counter substrate 13 side as the “display surface”. However, the present invention is not limited to this, and the image data BD may include fifth display data having a tag that can specify the corresponding “display surface”. When the “display surface” matches the tag, the fifth display data is displayed as it is. When the “display surface” is different from the tag, the sixth display data obtained by converting the fifth display data is displayed. It may be displayed.

  In the above embodiment, the display device 10 is set with the counter substrate 13 side (front surface 13a) as the initial display surface, but may be set with the element substrate 12 side (back surface 12a) as the initial display surface.

The top view of the whole about one Embodiment of an electrophoretic display device provided with the electrophoretic particle concerning the present invention. The top view which shows the planar structure of the electrophoretic display device of the embodiment. FIG. 3 is a cross-sectional view taken along the line 3-3 in FIG. Sectional drawing which shows the cross-section of the display panel of the embodiment. The circuit diagram which shows the circuit structure of the element substrate of the embodiment. The circuit diagram which shows the equivalent circuit of the pixel part of the embodiment. The top view which shows arrangement | positioning of the acceleration sensor of the embodiment. It is a side view explaining the detection of the inclination angle of the acceleration sensor of the embodiment, (a) is a side view showing a horizontal state, (b) is a side view showing a tilted state. FIG. 2 is a block diagram showing an electrical configuration of the electrophoretic display device of the embodiment. FIG. 3 is a plan view showing an image displayed on the electrophoretic display device of the embodiment, where (a) is a plan view showing an image displayed on the display surface, and (b) is displayed on the opposite side of the display surface. The top view which shows an image. FIG. 2 is a plan view showing an image displayed on the electrophoretic display device of the embodiment, where (a) is a plan view showing an image of the first page on the display surface (front surface), and (b) is a display surface (back surface). ) Is a plan view displaying the image of the second page. The top view which shows the image displayed on the electrophoretic display device in another example. The top view which shows the planar structure of the electronic book comprised by the electrophoretic display apparatus in another example.

Explanation of symbols

  g: Gravity direction, -g: Antigravity direction, AX: X axis angle signal, AY: Y axis angle signal, AZ ... Z axis angle signal, BD ... Image data, C1 ... Center line, C2 ... Point, Lx, Ly ... Horizontal line, PD ... display data, SC ... vertical synchronizing signal, Tr ... organic transistor, VD ... data timing signal, COM ... common terminal, Lx1, Lx2-Lxm ... data line, Ly1, Ly2-Lyn-1, Lyn ... scanning Line, B1, B2, B3, B4 ... button signal, SC1 to SCn ... scanning signal, VD1 to VDm ... data signal, 10 ... electrophoretic display device (display device), 10A ... electrophoretic display device, 11 ... electrophoretic display Panel (display panel), 11A ... first frame, 11B ... second frame, 12 ... element substrate, 12a ... back surface, 13 ... counter substrate, 13a ... front surface, 14 ... electrophoretic display layer, 15 ... back surface Base 16 ... element forming layer, 17 ... transparent substrate, 18 ... common electrode, 19 ... binder, 20 ... microcapsule, 22 ... display control circuit, 23 ... scanning line driving circuit, 24 ... data line driving circuit, 26 ... pixel, 27 ... Pixel electrode, 34 ... Electrophoretic dispersion medium, 35 ... Electrophoretic particle, 35b ... Black particle, 35w ... White particle, 42 ... Source electrode, 43 ... Drain electrode, 46 ... Gate electrode, 50 ... Control device, 51 ... Input device 52 ... acceleration sensor 52x ... X direction detection axis, 52y ... Y direction detection axis, 52z ... Z direction detection axis, 70 ... electronic book, 71 ... binder, 111-114 ... operation buttons.

Claims (10)

A transparent element substrate having a transparent pixel electrode;
A transparent counter substrate having a transparent common electrode corresponding to the pixel electrode;
An electrophoretic display layer sandwiched between the element substrate and the counter substrate;
A surface facing the upper side of the electrophoretic display device, and an acceleration sensor for detecting rotation of the electrophoretic display device;
Selection that selects one of the element substrate and the counter substrate as a display surface of the electrophoretic display layer based on a signal from the acceleration sensor, and selects display data according to a rotation direction of the electrophoretic display device And an electrophoretic display device. The electrophoretic display device according to claim 1 , wherein the counter substrate is selected as an initial display surface for the display surface. Holds multiple ordered display data,
When the display surface is rotated clockwise on a rotation axis parallel to the display surface and the display surface is switched by the selection unit, the display data displayed before the display surface is switched is next. Will display the ordered display data,
When the display surface rotates counterclockwise on a rotation axis parallel to the display surface and the display surface is switched by the selection unit, the display data displayed before the display surface is switched is displayed. The electrophoretic display device according to claim 1 or 2 , wherein previously ordered display data is displayed. Wherein the element light transmittance of the substrate is a light transmittance of the counter substrate are the same, the electrophoretic display device according to any one of claims 1 to 3. A transparent element substrate having a transparent pixel electrode;
A transparent counter substrate having a transparent common electrode corresponding to the pixel electrode;
An electrophoretic display layer sandwiched between the element substrate and the counter substrate;
A method of driving an electrophoretic display device comprising: an upper surface of the electrophoretic display device; and an acceleration sensor that detects rotation of the electrophoretic display device,
Based on a signal from the acceleration sensor, either the element substrate or the counter substrate is selected as a display surface of the electrophoretic display layer, and display data is selected according to the rotation direction of the electrophoretic display device. A method for driving an electrophoretic display device. First holding display data to be displayed on the counter substrate in advance,
When the counter substrate is selected as the display surface, the first display data is the display data,
6. The display data according to claim 5 , wherein when the element substrate is selected as the display surface, the first display data is converted into second display data for displaying on the element substrate to be the display data. Driving method of electrophoretic display device. Third display data when the counter substrate is the display surface;
Fourth display data when the element substrate is used as the display surface is prepared in advance,
6. The method for driving an electrophoretic display device according to claim 5 , wherein either the third data or the fourth data corresponding to the display surface selected by the selection unit is selected as the display data. . The display data held in advance is fifth display data to be displayed on either the counter substrate or the element substrate,
The fifth display data has a tag indicating whether the display data has any substrate as a display surface,
When the display surface selected by the selection means is a display surface indicated by the tag, the fifth display data is the display data,
Wherein when said display surface selected by the selection means does not display surface indicated by the tag, and the display data by the conversion to the sixth display data to be displayed on the display surface, according to claim 5 Driving method of electrophoretic display device. The display data uses the same data when the counter substrate is a display surface and when the element substrate is a display surface.
The method for driving an electrophoretic display device according to claim 5 , wherein the display surface selected by the selection unit is driven by changing the order of the pixel electrodes. Holding a plurality of said display data ordered;
When the display surface is rotated clockwise on a rotation axis parallel to the display surface and the display surface is switched, the display data is ordered next to the display data displayed before the display surface is switched. The display data is displayed,
When the display surface rotates counterclockwise on a rotation axis parallel to the display surface and the display surface is switched by the selection unit, the display data displayed before the display surface is switched is displayed. display data ordered before is displayed, the driving method of the electrophoretic display device according to any one of claims 5 to 9.

Images