JP2012118163A - Display medium and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display medium and a display device which can reduce the number of components without deteriorating display quality while including a double-sided display function and a touch input function.SOLUTION: A display medium 10 has a structure in which a main display panel 51, a touch panel 53, and a sub display panel 52 are stacked in a thickness direction. The main display panel 51 includes a film substrate 25 on which a common electrode 26 is formed, a display layer 43 having a microcapsule 40 in which multiple charged particles 41, 42 are stored, an extinction plate 24, and a main substrate 21 on which a pixel electrode 22 is formed. The touch panel 53 includes the main substrate 21 on which a detection electrode 23 is formed, and a film substrate 30 on which a detection electrode 31 is formed. The sub display panel 52 includes a film substrate 32 on which a common electrode 33 is formed, a display layer 44 having the microcapsule 40, the film substrate 30 which supports the display layer 44 between the film substrate 30 and the film substrate 32, and the pixel electrode 22 of the main substrate 21.

Description

  The present invention relates to a display medium and a display device capable of displaying images and the like on both sides.

  2. Description of the Related Art Conventionally, display media that can display characters, images, and the like using an electrophoresis phenomenon are known. This display medium has a structure in which a layer containing a large number of charged particles is disposed between two display substrates, at least one of which is transparent. An electric field is generated by applying a voltage between electrodes provided on the display substrate, and the charged particles move between the display substrates according to the electric field, whereby an image or the like is displayed on the display screen of the display medium. There is also known a display medium in which two such display media are overlapped so that both sides become a display screen so that different images can be displayed on both sides.

  A display medium in which a touch panel is integrally provided on a display substrate is known (see, for example, Patent Document 1). The touch panel electrically detects a position where an object such as a finger is in contact with or close to the touch panel. Normally, the touch panel is arranged on the display screen side for convenience of operation. However, in Patent Document 1, a flexible display substrate is used, and the touch panel is arranged on the back side opposite to the display screen. The visibility of the medium is improved.

JP 2007-322587 A

  However, when a display medium in which two display media described in Patent Document 1 are overlapped to display an image or the like on both sides is produced, the number of components constituting the display medium increases. Further, since two touch panel control devices and two image display control devices are required, there is a problem that the manufacturing cost of a display medium capable of double-sided display increases.

  The present invention has been made in order to solve the above-described problems, and provides a display medium and a display device that can display on both sides and have a touch input function but can reduce the number of components without degrading display quality. The purpose is to provide.

  According to the first aspect of the present invention, an electrode is formed on one surface side of a substrate having light transparency, and a first substrate in which an electrode is formed on one surface side of the substrate having light transparency, A second substrate disposed opposite to the first surface of the first substrate, a third substrate disposed between the first substrate and the second substrate, and facing each other; A first layer disposed between the first substrate and the third substrate and including a plurality of charged particles, and disposed between the second substrate and the third substrate. A second layer, a plurality of pixel electrodes formed on one surface side of the third substrate, a second surface of the third substrate, the other surface of the first substrate, and the first substrate A detection electrode for electrically detecting the position of an object in contact with or close to at least one of the other surfaces of the two substrates. Display medium is provided.

  In the display medium according to the first aspect, an image or the like formed on the first layer can be viewed through the first substrate, and an image or the like formed on the second layer can be viewed through the second substrate. In addition, by providing the detection electrode, a function of detecting the position of an object such as a finger that is in contact with or close to a display screen such as an image can be obtained. Since this detection electrode is disposed between the first layer and the second layer, an image or the like formed on the first layer or the second layer is displayed via the first substrate or the second substrate. Is not disturbed by the detection electrode. Therefore, a clear image with high display quality can be displayed on both sides of the display medium. Further, detection of an operation input (touch input) performed by a finger or the like in accordance with the display on the first layer and detection of a touch input performed in accordance with the display on the second layer are performed with one detection electrode. Can be shared. Therefore, the number of parts constituting the display medium can be reduced as compared with the case where the detection electrode for display of the first layer and the detection electrode for display of the second layer are provided. Furthermore, since there is only one detection electrode, only one circuit for driving the detection electrode is sufficient, and the number of parts can be reduced and power consumption can be reduced. In addition, since the image or the like formed on the first layer and the image or the like formed on the second layer can be formed by driving the pixel electrode on one surface side of the third substrate, A circuit for driving the pixel electrode can be shared without providing the circuit for the first layer and the second layer, so that the number of parts can be reduced and the power consumption can be reduced.

  In the display medium of the first aspect, an electrode is formed on one surface side of a flexible substrate, and the one surface is opposed to the detection electrode with a predetermined gap. And a fourth substrate disposed between the second layer and the second layer. In the first aspect, the second substrate may be a substrate having flexibility and disposed on the other surface side of the third substrate. By adopting a so-called resistive film method that detects the contact position of a finger or the like by bending the fourth substrate and making the electrode of the fourth substrate conductive with the detection electrode of the third substrate, the detection accuracy of the contact position is high. A touch input function can be provided. Touch input may be performed from the flexible second substrate side, and the first substrate does not need to be flexible. Therefore, since the substrate made of glass or the like can be used for the first substrate, the strength of the display medium can be increased.

  The display medium of the first aspect is disposed on at least one side of the other surface of the first substrate and the other surface of the second substrate, and the other surface of the first substrate or the other surface of the second substrate. You may further provide the 1st detection means to detect the contact or proximity | contact of the object to. In the first aspect, the first substrate and the third substrate may be flexible substrates. By providing the first detection means, it is possible to discriminate between a case where touch input is performed from the first substrate side and a case where touch input is performed from the second substrate side. That is, touch input can be performed from both sides of the display medium, which is highly convenient.

  According to the second aspect of the present invention, the other surface of the first substrate or the other surface of the second substrate is disposed on at least one side of the other surface of the first substrate and the other surface of the second substrate. A first detection means for detecting contact or proximity of an object to the surface of the substrate and the other surface side of the third substrate, electrically connected to the detection electrode, and the contact position to the detection electrode A display medium according to a first aspect, further comprising: a second detection means for detecting the position; and the contact position connected to the second detection means of the display medium and detected by the second detection means. There is provided a display device including a calculation means for performing a calculation. By adopting a so-called surface-capacitance method in which touch input to the detection electrode is detected by the second detection means, the display medium does not perform a mechanical operation, and thus durability is improved. Further, by providing the first detection means, it is possible to discriminate between a case where touch input is performed from the first substrate side and a case where touch input is performed from the second substrate side. That is, touch input can be performed from both sides of the display medium, which is highly convenient.

3 is a front view illustrating a schematic configuration of the display device 1. FIG. It is sectional drawing of the display medium 10 seen in the arrow direction in the dashed-dotted line AA of FIG. 3 is a block diagram showing an electrical configuration of the display device 1. FIG. It is a flowchart of a display control program. 3 is a cross-sectional view of a display medium 110 of the display device 101. FIG. FIG. 6 is a cross-sectional view of the display medium 110 viewed in the direction of the arrows along the one-dot chain line BB in FIG. 4 is a cross-sectional view of a display medium 210 of the display device 201. FIG. It is a flowchart which shows S221 of the display control program in 3rd Embodiment.

  Hereinafter, a display device 1 according to a first embodiment of the present invention will be described with reference to the drawings. The drawings referred to below are used to explain technical features that can be adopted by the present invention. The configuration of the apparatus, the flowcharts of various processes, and the like described in the drawings are not intended to be limited to these, but are merely illustrative examples.

  A display device 1 shown in FIG. 1 is a thin plate-like device that can display a document, an image, or the like on a display screen 3 by a built-in display medium 10. Although not shown in FIG. 1, a display screen 4 (see FIG. 2) is also provided on the back surface of the display device 1 (the surface on the back side of the paper in FIG. 1). That is, the display device 1 has display screens 3 and 4 on both sides of the housing 2 and can display a document, an image, and the like independently of each other, and can be used for applications such as an electronic signboard. . Hereinafter, for convenience, the display screen 3 of the display medium 10 will be described as the main surface of the display device 1, and the display screen 4 of the display medium 10 will be described as the back surface of the display device 1.

  The display device 1 accommodates a display medium 10, a control board 7, and a battery 8 to be described later in the housing 2. The display medium 10 and the battery 8 are electrically connected to the control board 7 by a flexible printed circuit board (FPC) 6, respectively. In addition, a plurality of operation buttons 5 including a power switch and the like are provided on the control board 7 and are arranged to be operated from the outside of the housing 2. The display device 1 may not include the battery 8, and power may be supplied to the display medium 10 and the control board 7 from an external power source. Alternatively, power supply from an external power source and power supply from the battery 8 may be used in combination.

  Next, the structure of the display medium 10 will be described with reference to FIGS. The display medium 10 is a medium that can display an image or the like by a known electrophoretic display element. As shown in FIG. 2, the display medium 10 is formed by laminating substantially rectangular members in a layer shape, and is formed in a plate shape. The display medium 10 according to the first embodiment has a structure in which a protective film 27, a main display panel 51, a touch panel 53, a sub display panel 52, and a protective film 34 are stacked in this order in the thickness direction. For convenience, in the following description, a surface on the display screen 3 side of each member (including the display medium 10 itself) constituting the display medium 10 is a main surface, and a surface on the display screen 4 side is a back surface.

  First, the main display panel 51 will be described. The main display panel 51 is a panel-like structure for displaying an image or the like on the main surface (display screen 3) of the display medium 10. The main display panel 51 includes a film substrate 25 on which a common electrode 26 is formed, a display layer 43 including microcapsules 40 in which a large number of charged particles 41 and 42 are accommodated, a light reduction plate 24, and a pixel electrode 22. And the main substrate 21.

  The main substrate 21 is a flexible substrate made of metal or a plastic film such as polyethylene terephthalate (PET). A pixel electrode 22 is formed on the main surface of the main substrate 21 (the surface on the display screen 3 side). The pixel electrode 22 is formed by arranging a thin film transistor (TFT) (not shown) and an electrode plate for each pixel such as an image displayed on the display screens 3 and 4 and connecting them by a matrix wiring. The individual TFTs of the pixel electrode 22 are driven by a known active matrix system, and a voltage is applied to the electrode plate for each pixel to generate an electric field between the common electrodes 26 and 33 described later.

  A film substrate 25 is disposed to face the surface (main surface) of the main substrate 21 on which the pixel electrodes 22 are formed. The film substrate 25 is a film-like substrate made of PET in the first embodiment, and has light transmittance and flexibility. On the surface (back surface) of the film substrate 25 on the main substrate 21 side, a common electrode 26 is formed by depositing indium tin oxide (ITO) over the entire surface. That is, the common electrode 26 is disposed so as to face the individual pixel electrodes 22 of the main substrate 21 in the thickness direction of the display medium 10. A display layer 43 and a light reducing plate 24 are provided between both electrodes.

  The light reducing plate 24 is a plate body made of a polyester film to which a predetermined amount of dye or pigment is added, and reduces or blocks light transmitted through the light reducing plate 24. The light reduction plate 24 is disposed on the pixel electrode 22 (on the display screen 3 side), and covers the entire area where the pixel electrode 22 is formed (display area 9 such as an image on the display screen 3). The light reducing plate 24 suppresses generation of a TFT leakage current in the pixel electrode 22 due to external light incident from the display screen 3 side. In addition, the dimming plate 24 also has an effect of preventing an image or the like displayed on the display screen 4 or 3 from becoming difficult to see due to light incident from the display screen 3 or 4 side and transmitted through each layer.

  The display layer 43 is a layer formed by including a large number of microcapsules 40 containing a large number of charged particles 41 and 42 in a polymer binder (not shown). The display layer 43 is interposed between the pixel electrode 22 of the main substrate 21 and the common electrode 26 of the film substrate 25. In the first embodiment, the above-described dimming plate 24 is further interposed between the display layer 43 and the pixel electrode 22. Each microcapsule 40 accommodates charged particles 41 and 42 dispersed therein in a hydrocarbon-based fluid. The charged particles 41 are positively charged black particles, and the charged particles 42 are negatively charged white particles (the polarity of charging may be reversed). Although details will be described later, the charged particles 41 and 42 move (migrate) within the microcapsule 40 in accordance with the direction of the electric field generated between each pixel electrode 22 and the common electrode 26, thereby causing the display screen 3. An image or the like is displayed on the screen.

  Next, the touch panel 53 will be described. The touch panel 53 is a panel-like structure for electrically detecting a position where an object such as a finger contacts (or approaches). The touch panel 53 includes the main substrate 21 on which the detection electrode 23 is formed and the film substrate 30 on which the detection electrode 31 is formed.

  The main substrate 21 is as described above, and the detection electrode 23 is formed by depositing ITO on the back surface (the surface on the display screen 4 side) of the main substrate 21. Similar to the film substrate 25 of the main display panel 51, the film substrate 30 is a film-like substrate made of PET and has flexibility. The film substrate 30 is disposed on the display screen 4 side of the main substrate 21 so as to face the main substrate 21 in a state of being separated from the main substrate 21. On the surface (main surface) of the film substrate 30 on the main substrate 21 side, a detection electrode 31 is formed by depositing ITO over the entire surface. A predetermined gap is secured between the detection electrode 23 of the main substrate 21 and the detection electrode 31 of the film substrate 30. Unless the external pressing force is applied to the main substrate 21 and the film substrate 30, the detection electrode 23 and the detection electrode 31 are maintained in a non-contact state. The touch panel 53 has a known resistance at a position where the detection electrode 23 and the detection electrode 31 are in contact (electrically connected) because the main substrate 21 and the film substrate 30 are locally bent by an external pressing force. Detection is performed using a film system.

  Next, the sub display panel 52 will be described. Similar to the main display panel 51, the sub display panel 52 is a panel-like structure for displaying an image or the like on the back surface (display screen 4) of the display medium 10. The sub display panel 52 includes the film substrate 32 on which the common electrode 33 is formed, the display layer 44 including the microcapsules 40 described above, and the film substrate 30 that holds the display layer 44 between the film substrate 32, The pixel electrode 22 is formed on the main substrate 21.

  The film substrate 32 is a film-like substrate made of PET like the film substrate 25 of the main display panel 51, and has light transmittance and flexibility. The common electrode 33 is formed on the surface (main surface) of the film substrate 32 on the main substrate 21 side by vapor deposition of ITO. The display layer 44 has the same configuration as that of the display layer 43, and includes a large number of microcapsules 40 that accommodate a large number of charged particles 41 and 42 in a polymer binder (not shown) between the film substrates 30 and 32. Is the layer to be played. The microcapsule 40 of the display layer 44 is disposed via the touch panel 53 between the pixel electrode 22 of the main substrate 21 and the common electrode 33 of the film substrate 32, and an electric field is generated between the pixel electrode 22 and the common electrode 33. As a result, an image or the like is displayed on the display screen 4.

  Thus, each board | substrate and member which comprise the main display panel 51, the sub display panel 52, and the touch panel 53 are arrange | positioned at layered form, and are mutually joined by the adhesive agent etc. The main substrate 21 is formed larger in the surface direction than other substrates constituting the display medium 10. The silicon mold 35 goes around the side surface along the main surface of the main substrate 21 (surface on the display screen 3 side) and the side surface of the main display panel 51 that protrude in the surface direction from other substrates. Is formed. The main surface (surface on the display screen 3 side) of the film substrate 25 is covered and protected by the protective film 27 together with the silicon mold 35. The protective film 27 is a light-transmitting plastic film made of PET and has flexibility. Similarly, along the back surface (surface on the display screen 4 side) of the portion of the main substrate 21 that protrudes in the surface direction from the other substrates and the side surfaces of the touch panel 53 and the sub display panel 52, the silicon mold 36 is It is formed around the side surface. The back surface (surface on the display screen 4 side) of the film substrate 32 is also covered and protected by the protective film 34 together with the silicon mold 36. Similarly, the protective film 34 is made of a plastic film made of PET and having optical transparency and flexibility.

  The main surface (display screen 3) of the protective film 27 is an infrared light emitting unit 11 and an infrared light receiving unit 12 (see FIG. 1) as contact sensors that detect contact (or proximity) of a finger or the like to the display screen 3. Is provided. As shown in FIGS. 1 and 2, the infrared light emitting unit 11 and the infrared light receiving unit 12 are provided along the outer periphery of the display region 9 so as not to overlap the display region 9 such as an image on the display screen 3 in the thickness direction. ing. As shown in FIG. 1, the infrared light emitting units 11 are provided on two sides of the rectangular display area 9, and the infrared light receiving unit 12 is provided on each side facing each side. The touch sensor is driven while the touch panel 53 is being driven, and the infrared light emitted from the infrared light emitting unit 11 is received by the infrared light receiving unit 12. When the infrared light reception is blocked by a finger or the like, the touch sensor 53 displays the finger on the display screen 3. Contact is detected. That is, when there is an operation input (touch input) with a finger or the like on the touch panel 53, if there is detection by the contact sensor, it is determined that the finger or the like has touched the display screen 3, and there is no detection by the contact sensor. It is determined that a finger or the like has touched the display screen 4.

  Next, the electrical configuration of the display device 1 will be described with reference to FIG. As shown in FIG. 3, the display device 1 includes a CPU 60 that controls the display device 1 and the like on the control board 7. The CPU 60 is electrically connected to the ROM 61, the RAM 62, and the flash memory 63, and can access the respective storage areas. The ROM 61 is a read-only storage device that stores a basic program executed by the CPU 60. A display control program to be described later is also stored in a predetermined storage area of the ROM 61. The RAM 62 is a readable / writable storage device that temporarily stores data. The flash memory 63 is a readable and writable nonvolatile storage device, and stores data such as characters and images to be displayed on the display screens 3 and 4 of the display device 1.

  The control board 7 is further provided with an input / output interface 64, a touch panel (TP) controller 71, a voltage generation circuit 72, and an electrophoretic display (EPD) controller 73, and is connected to the CPU 60. The input / output interface 64 is a communication interface such as USB or Bluetooth (registered trademark), and is used for input / output of data such as characters and images displayed on the display screens 3 and 4 of the display device 1.

  The voltage generation circuit 72 generates a voltage to be applied to the main display panel 51, the sub display panel 52 and the touch panel 53 from the power supplied from the battery 8. In the first embodiment, voltage is alternatively applied to the main display panel 51, the sub display panel 52, and the touch panel 53 in accordance with a display control program to be described later.

  The TP controller 71 detects a contact position (that is, a contact position of a finger or the like) between the detection electrode 23 and the detection electrode 31 of the touch panel 53. In the position detection, the voltage generation circuit 72 applies a predetermined voltage (for example, 5 V) between the opposite sides of the detection electrode 23 and the detection electrode 31, and the TP controller 71 detects the partial pressure value at the contact position between the two. Is done by. The TP controller 71 A / D converts the detected partial pressure value and outputs it to the CPU 60. In addition, the TP controller 71 is in a conductive state (hereinafter also referred to as “PEN DOWN” state) between the detection electrode 23 and the detection electrode 31 or is in an insulated state (hereinafter referred to as “PEN UP”). A signal (which is also referred to as a PEN_DOWN signal and a PEN_UP signal for convenience) is output to the CPU 60.

  If the voltage applied to the detection electrodes 23 and 31 by the voltage generation circuit 72 is a drive voltage (for example, 5 V) of the CPU 60, the voltage division value detected by the detection electrodes 23 and 31 is directly input to the port of the CPU 60. Also good. In this case, the CPU 60 may function as the TP controller 71 by directly acquiring the partial pressure value using the A / D conversion function of the port of the CPU 60.

  The EPD controller 73 controls the voltage applied to each pixel electrode 22 in order to display an image or the like on the main display panel 51 and the sub display panel 52. In the first embodiment, the display of images on the main display panel 51 and the sub display panel 52 is performed independently (alternatively) including the driving of the touch panel 53 described above. Further, the operation button 5 and the contact sensor (the infrared light emitting unit 11 and the infrared light receiving unit 12) are connected to the CPU 60.

  Next, an operation when forming an image or the like on the main display panel 51 and the sub display panel 52 will be briefly described with reference to FIG. Since the main display panel 51 and the sub display panel 52 have the same image forming method, the case of the main display panel 51 will be described below. Formation of an image or the like on the main display panel 51 is performed by a known electrophoresis method. At the time of image formation, the common electrode 26 is used as a reference potential, and the TFT of each pixel electrode 22 is controlled by the EPD controller 73 so that a positive or negative voltage is applied from the voltage generation circuit 72. As a result, an electric field having a direction corresponding to the sign of the applied voltage is generated between the individual pixel electrode 22 and the common electrode 26.

  As described above, the charged particles 41 and 42 in the microcapsule 40 disposed between the pixel electrode 22 and the common electrode 26 are charged positively or negatively, respectively. Therefore, each of the charged particles 41 and 42 moves to the pixel electrode 22 side or the common electrode 26 side in the microcapsule 40 according to the direction of the electric field. For example, when a voltage higher than that of the common electrode 26 is applied to a certain pixel electrode 22, the positively charged black charged particles 41 move to the common electrode 26 side, and negatively charged white charged particles. 42 moves to the pixel electrode 22 side. When viewed from the display screen 3 side, the white charged particles 42 on the pixel electrode 22 side are blocked by the black charged particles 41 on the common electrode 26 side, and the display color near the pixel electrode 22 on the display screen 3 is black. It becomes. When a voltage lower than that of the common electrode 26 is applied to the pixel electrode 22, the display color near the pixel electrode 22 on the display screen 3 is white. In this way, an image or the like is displayed on the display screen 3 by controlling the voltage applied to each pixel electrode 22. Since the positions of the charged particles 41 and 42 in the microcapsule 40 are maintained even when the application of voltage between the pixel electrode 22 and the common electrode 26 is stopped, the display state of an image or the like on the display screen 3 is It is maintained as it is.

  Next, an operation when the position of the contact position on the touch panel 53 by the TP controller 71 is detected will be described. When a finger or the like comes into contact with the display screen 3, the protective film 27, the film substrate 25, the display layer 43, and the main substrate 21 bend in the thickness direction at the contact position. Then, the detection electrode 23 and the detection electrode 31 are brought into conduction at the contact position. Alternatively, even when a finger or the like touches the display screen 4, the protective film 34, the film substrate 32, the display layer 44, and the film substrate 30 bend in the thickness direction at the contact position, and the detection electrode 23 and the detection electrode 31 are in contact with each other. Conducts in position.

  In the touch panel 53, a predetermined voltage (for example, 5 V) is applied between the opposite sides of both ends in the first axial direction on the plane of the detection electrode 23 by the voltage generation circuit 72. In the TP controller 71, the potential of the detection electrode 31 is obtained, so that the first axial direction (for example, the vertical direction of the display screens 3 and 4) in the conduction position between the detection electrode 31 and the detection electrode 23 (ie, the contact position of a finger or the like) Direction) partial pressure value is detected. The detected partial pressure value in the first axial direction is A / D converted and input from the TP controller 71 to the CPU 60.

  Next, in the touch panel 53, a predetermined voltage is applied between the opposite sides of both ends in the second axial direction orthogonal to the first axial direction in the plane of the detection electrode 23 by the voltage generation circuit 72. In the TP controller 71, by obtaining the potential of the detection electrode 31, a partial pressure value in the second axial direction (for example, the lateral direction of the display screens 3 and 4) is detected as described above. The detected partial pressure value in the second axial direction is A / D converted and input from the TP controller 71 to the CPU 60. The CPU 60 determines the conduction position (that is, the contact position of a finger or the like) in the plane direction between the detection electrode 23 and the detection electrode 31 based on the biaxial partial pressure value (or the partial pressure ratio) detected by the TP controller 71. Coordinates can be obtained.

  Next, the flow of processing performed in the display device 1 of the first embodiment will be described with reference to the flowchart of the display control program in FIG. The display control program described below is executed by the CPU 60 together with other programs (not shown) according to a sequence when the CPU 60 is started up when the power of the display device 1 is turned on. Examples of the other programs include a main program that manages the overall drive of the display device 1 and a program that performs image processing related to screen rewriting. Note that data, flags, and the like temporarily generated during execution of the display control program are temporarily stored in a data processing storage area secured in the RAM 62. Hereinafter, each step of the flowchart is abbreviated as “S”.

  When the display device 1 is turned on and the display control program shown in FIG. 4 is executed, a signal for switching the TP controller 71 to the operating state (ON state) is output (S10). The TP controller 71 stands by in a state where the partial pressure value of the detection electrode 23 or the detection electrode 31 can be detected. In addition, when the display device 1 is activated, operation checks of the circuits mounted on the control board 7 such as the voltage generation circuit 72, the TP controller 71, and the EPD controller 73 are performed by another program (not shown). In S11, it waits for the operation check of the voltage generation circuit 72 to be completed (S11: NO).

  When the operation check of the voltage generation circuit 72 is completed and a voltage generation command is received from the other program (S11: YES), the CPU 60 generates a voltage (for example, 5V) to be applied to the touch panel 53 in the voltage generation circuit 72. An instruction signal to be output is output (S12). In the voltage generation circuit 72, as described above, a voltage of 5V applied between the opposite sides of the detection electrode 23 of the touch panel 53 is generated. Next, the CPU 60 outputs to the TP controller 71 an EN_ON command that validates the driving of the TP controller 71 (S13). At this time, the contact sensors (the infrared light emitting unit 11 and the infrared light receiving unit 12) are also energized and are in a driving state.

  While the finger or the like is not in contact with the touch panel 53 and the detection electrode 23 and the detection electrode 31 are in an insulated state, the PEN_UP signal is output from the TP controller 71, and the CPU 60 stands by (S15: NO). When a finger or the like touches the touch panel 53 and the detection electrode 23 and the detection electrode 31 are in a conductive state (PEN DOWN), the TP controller 71 outputs a PEN_DOWN signal that reports the conductive state to the CPU 60. Further, the TP controller 71 starts detecting the contact position of the finger or the like (conduction position between the detection electrode 23 and the detection electrode 31). The TP controller 71 cooperates with the voltage generation circuit 72 to acquire the potential of the detection electrode 31 as a partial pressure value in the first axial direction when a voltage of 5 V is applied in the first axial direction of the detection electrode 23. Hold in the buffer. Further, the TP controller 71 cooperates with the voltage generation circuit 72 to acquire the potential of the detection electrode 23 as a partial pressure value in the second axial direction when a voltage of 5 V is applied in the second axial direction of the detection electrode 31. And keep it in the buffer. The TP controller 71 performs A / D conversion on the respective partial pressure values in the first axial direction and the second axial direction held in the buffer, and outputs them to the CPU 60. When receiving the PEN_DOWN signal from the TP controller 71, the CPU 60 proceeds to S16 (S15: YES). Further, the CPU 60 stores the partial pressure value received from the TP controller 71 in the RAM 62.

  Thereafter, the TP controller 71 repeatedly acquires partial pressure values in the first axial direction and the second axial direction. The acquired partial pressure value is overwritten and held in the buffer. Further, if the finger or the like that has touched the touch panel 53 is maintained in a contact state (the detection electrode 23 and the detection electrode 31 are in a conductive state), the TP controller 71 continuously outputs the PEN_DOWN signal. The CPU 60 stands by while receiving the PEN_DOWN signal from the TP controller 71 (S16: NO). During standby, when a contact of a finger or the like to the display screen 3 is detected by the contact sensors (the infrared light emitting unit 11 and the infrared light receiving unit 12), a flag indicating the contact (hereinafter, for convenience) , Called “contact flag”) and stored in the RAM 62.

  When the finger or the like is removed from the touch panel 53 and the detection electrode 23 and the detection electrode 31 are in an insulated state (PEN UP), the TP controller 71 outputs a PEN_UP signal to the CPU 60. Further, the TP controller 71 performs A / D conversion on the latest partial pressure values held in the buffer in the first and second axial directions, and outputs them to the CPU 60 to output the contact position (such as a finger) The detection of the conduction position) is terminated. When receiving the PEN_UP signal from the TP controller 71, the CPU 60 proceeds to S17 (S16: YES). Further, the CPU 60 stores the partial pressure value received from the TP controller 71 in the RAM 62. The CPU 60 determines the conduction position in the planar direction between the detection electrode 23 and the detection electrode 31 based on the partial pressure values in the first axial direction and the second axial direction when the PEN DOWN state changes to the PEN UP state. The coordinates of the (contact position of the finger or the like) are obtained (S17). The calculation of the coordinates of the contact position may be performed by mounting a microcomputer (not shown) on the TP controller 71, and the CPU 60 may acquire the coordinates of the contact position obtained by the TP controller 71 in S17.

  Here, when the contact flag is established, an operation input (touch input) with a finger or the like is performed on the display screen 3 side, and when the contact flag is not established, the touch input is performed on the display screen 4 side. It is judged that this was done. The CPU 60 confirms whether the input operation is valid based on the coordinates obtained in S17 and the state of the contact flag. For example, an operation icon or the like is displayed on the main display panel 51 (display screen 3). When the touch panel 53 is operated and the PEN_DOWN signal and the PEN_DOWN signal are received, if the contact flag is not established, it is determined that the touch input is made on the display screen 4 side. Even if the contact flag is established, if the coordinates obtained in S17 are not within the coordinate area occupied by the icon displayed on the main display panel 51 (display screen 3), the touch input is the icon coordinates. It is determined that it was not made for the area. In such a case, it is determined that the input operation is invalid (S18: NO), and the process returns to S15.

  On the other hand, if the CPU 60 determines in S18 that the input operation is valid based on the state of the contact flag established according to the detection result of the contact sensor and the coordinates obtained in S17 (S18: YES), the process proceeds to S20. In S20, the CPU 60 outputs to the TP controller 71 an EN_OFF command that invalidates the driving of the TP controller 71 (S20). Further, the CPU 60 outputs an instruction signal for stopping the generation of the voltage applied to the touch panel 53 to the voltage generation circuit 72. Further, the energization of the contact sensors (the infrared light emitting unit 11 and the infrared light receiving unit 12) is also stopped, and the non-driven state is entered.

  Proceeding to S21, if the contact flag is established, the CPU 60 executes the processing of S22 to S26 in order to rewrite the display content of the main display panel 51 (display screen 3) (S21: YES). First, the CPU 60 outputs an instruction signal for generating a voltage (for example, ± 20 V) to be applied to the main display panel 51 to the voltage generation circuit 72 (S22). In the voltage generating circuit 72, as described above, a voltage of ± 20 V (Vcom1 voltage) applied between the pixel electrode 22 and the common electrode 26 of the main display panel 51 is generated. Next, the CPU 60 outputs to the EPD controller 73 an EN_ON command that validates the driving of the EPD controller 73 (S23).

  The CPU 60 outputs a command (EPD1 display rewrite command) for instructing rewriting of an image or the like displayed on the display screen 3 toward a program for performing image processing (not shown) (S25). The EPD1 display rewriting command may be a predetermined flag shared between the image processing program and the display control program, for example. In the image processing program, the CPU 60 controls the TFT of each pixel electrode 22 by controlling the EPD controller 73 when receiving the EPD1 display rewrite command. Thus, the Vcom1 voltage generated by the voltage generation circuit 72 is applied to each pixel electrode 22 with the common electrode 26 as a reference potential, and the potential of the pixel electrode 22 is controlled to + 20V or −20V. As described above, the charged particles 41 and 42 in the microcapsule 40 move to the pixel electrode 22 side or the common electrode 26 side in the microcapsule 40 according to the direction of the electric field. Rewriting is performed.

  When the rewriting of the image or the like on the display screen 3 is completed, the CPU 60 outputs an EN_OFF command for invalidating the driving of the EPD controller 73 to the EPD controller 73 (S26). Further, the CPU 60 outputs an instruction signal for stopping the generation of the voltage applied to the main display panel 51 to the voltage generation circuit 72. And it returns to S12 and the input operation by the touch panel 53 is detected by performing the process of S12-S20.

  On the other hand, if the contact flag is not established in S21, the CPU 60 executes the processes of S32 to S36 in order to rewrite the display content of the sub display panel 52 (display screen 4) (S21: NO). In S32 to S36, the same processing as in S22 to S26 is performed with the processing target as the sub display panel 52, so the following description will be simplified. The CPU 60 outputs an instruction signal for generating a voltage (Vcom2 voltage) to be applied to the sub display panel 52 to the voltage generation circuit 72 (S32), and then outputs an EN_ON command to the EPD controller 73 (S33). The CPU 60 outputs a command (EPD2 display rewrite command) instructing rewriting of an image or the like displayed on the display screen 4 to the program (not shown) for performing the image processing (S35). When the rewriting of the image displayed on the display screen 4 is completed as described above, the CPU 60 outputs an EN_OFF command to the EPD controller 73 (S36), and further supplies the voltage generation circuit 72 with the voltage applied to the sub display panel 52. An instruction signal for stopping generation is output. Then, the process returns to S12.

  As described above, the display device 1 according to the first embodiment can display images and the like on both surfaces of the display medium 10. That is, an image or the like formed on the display layer 43 can be seen through the film substrate 25 on the main surface (display screen 3) side of the display medium 10, and the film substrate 32 can be seen on the back surface (display screen 4) side. Thus, an image formed on the display layer 44 can be seen. Furthermore, by providing the detection electrode 23, a function of detecting the position of an object such as a finger that is in contact with (or close to) the display screens 3 and 4 can be obtained. Since the detection electrode 23 is disposed between the display layer 43 and the display layer 44, the display via the film substrate 25 or the film substrate 32 such as an image formed on the display layer 43 or the display layer 44 is detected by the detection electrode. 23 is not obstructed. Therefore, a clear image with high display quality can be displayed on both surfaces of the display medium 10.

  Further, detection is performed in accordance with the detection of touch input performed in accordance with the display of the display layer 43 (display of an image or the like on the display screen 3) and the display of the display layer 44 (display of an image or the like on the display screen 4). The detection of touch input can be performed in common with one detection electrode 23. Therefore, the number of components constituting the display medium 10 can be reduced as compared with the case where the detection electrode for display of the display layer 43 and the detection electrode for display of the display layer 44 are provided. Furthermore, since there is only one detection electrode 23, only one circuit (the voltage generation circuit 72 and the TP controller 71) for driving the detection electrode 23 is sufficient, and the number of parts can be reduced and the power consumption can be reduced. .

  In addition, an image or the like formed on the display layer 43 and an image or the like formed on the display layer 44 can be formed by driving the pixel electrode 22 of the main substrate 21. Therefore, the circuit for driving the pixel electrode 22 (the voltage generation circuit 72 and the EPD controller 73) can be shared without providing the display layer 43 and the display layer 44, respectively, and the number of parts can be reduced. In addition, power consumption can be reduced. Furthermore, by providing a contact sensor (infrared light emitting unit 11 and infrared light receiving unit 12), when touch input is performed from the film substrate 25 side (display screen 3 side) and the film substrate 32 side (display screen 4 side). It is possible to discriminate from the case where a touch input is performed. That is, since touch input can be performed from both sides of the display medium 10, it is highly convenient.

  The display medium 10 employs a so-called resistive film method in which a contact position of a finger or the like is detected by the film substrate 30 being bent and the detection electrode 31 of the film substrate 30 being electrically connected to the detection electrode 23 of the main substrate 21. Thus, a touch input function with high contact position detection accuracy can be provided at a low cost.

  Next, the display apparatus 101 concerning the 2nd Embodiment of this invention is demonstrated. The display device 101 includes a display medium 110 illustrated in FIG. 5 and a touch panel 153 that detects contact and the like using a surface capacitance method. Accordingly, the other configuration of the display device 101 is the same as that of the display device 1 of the first embodiment, and the display medium 110 will be described below. The touch panel 153 of the display medium 110 is formed by depositing ITO on the main substrate 121 made of glass and having no flexibility and the back surface of the main substrate 121 (the surface on the display screen 4 side), and functions as a conductive film. And a detection electrode 123. As shown in FIG. 6, detection electrodes 125 are provided at the four corners of the plane of the detection electrode 123 for detecting positions where a finger or the like is in contact with or close to the detection electrode 123. The four detection electrodes 125 are connected to a TP controller 71 (see FIG. 3), and the TP controller 71 detects the magnitude of the current flowing through each detection electrode 125 and performs A / D conversion.

  Since the detection of the contact position by the surface capacitive touch panel 153 is known, the detection method will be briefly described below. When a finger or the like touches or approaches the detection electrode 123 (conductive film) having a uniform electric field formed on the entire surface, the electrostatic capacitance between the detection electrode 123 and the finger or the like changes due to electrostatic coupling. As a result, a change occurs in the current flowing through the detection electrodes 125 at the four corners. The magnitude of the current change flowing through the detection electrode 125 is inversely proportional to the distance between the contact position of the finger or the like on the detection electrode 123 and the detection electrode 125. Therefore, the TP controller 71 obtains a distance ratio between each detection electrode 125 and the contact position by obtaining a ratio of current magnitudes in the detection electrodes 125 at the four corners. Then, based on the size of the display area 9, the TP controller 71 calculates the coordinates of the contact position that satisfies the distance ratio using a known arithmetic expression, and outputs it to the CPU 60. The calculation of the coordinates of the contact position may be performed by mounting a microcomputer (not shown) on the TP controller 71, and the CPU 60 may acquire the coordinates of the contact position obtained by the TP controller 71 in S17. Further, the TP controller 71 may detect the magnitude of the current flowing through the detection electrode 125 and perform A / D conversion, and the CPU 60 may calculate the coordinates of the contact position.

  The main display panel 151 and the sub display panel 152 of the display medium 110 are the same as those in the first embodiment except that a main substrate 121 made of glass and having no flexibility is used. Is omitted. Further, the structure of the display device 101 and the operation related to display control are the same as those of the display device 1 of the first embodiment, and the description thereof is omitted. The protective films 27 and 34 and the film substrates 25 and 32 are flexible in the first embodiment, but may not be flexible in the second embodiment. For example, you may form using glass etc.

  As described above, the display device 101 according to the second embodiment employs a so-called surface capacitance method in which a touch input to the detection electrode 123 is detected by the detection electrode 125, whereby the display medium 110 is mechanical. Long life can be realized because no proper operation is performed. Further, by providing the contact sensors (infrared light emitting unit 11 and infrared light receiving unit 12), it is determined whether a touch input is performed from the film substrate 25 side or a touch input is performed from the film substrate 32 side. be able to. That is, since touch input can be performed from both sides of the display medium 110, convenience is high.

  Next, a display device 201 according to the third embodiment of the present invention will be described. The display medium 210 of the display device 201 of the third embodiment shown in FIG. 7 is substantially the same as the configuration of the display medium 10 of the first embodiment. The difference is that the main substrate 221 of the display medium 210 is a substrate made of glass similar to that of the second embodiment and having no flexibility, and a contact sensor (infrared light emitting unit 11 and infrared light receiving unit 12). ). That is, the touch panel 253 of the display medium 210 can detect the contact of a finger or the like on the display screen 4 side, and does not detect the contact of a finger or the like on the display screen 3 side.

  The structure and electrical configuration of the display device 201 having the display medium 210 having such a configuration are the same as those shown in FIGS. 1 and 3, except that the contact sensor (the infrared light emitting unit 11 and the infrared light receiving unit 12) is not provided. This is the same as the display device 1 of the first embodiment, and a description thereof is omitted. The operation related to the display control in the display device 201 is performed according to the same display control program (see FIG. 4) as that in the first embodiment, but the processing related to the contact sensor (the contact sensor energization control in S13 and S20) is performed. I will not. Also, instead of the determination process of S21, the determination process of S221 shown in FIG. 8 is performed, and the process based on the touch input on the touch panel 253 is branched.

  For example, an icon or the like for operating the display device 201 is displayed on the sub display panel 252 (display screen 4) by a program for performing image processing (not shown). 4, the touch position of the finger or the like on the display screen 4 is detected by the touch panel 253 through the processes of S12 to S20. Next, the process proceeds to S221 shown in FIG. 8, and the processing defined for the icon corresponding to the contact position detected by the touch panel 253 (the icon instructed by the touch input) is the main display panel 251 (display screen 3) side. 4 includes rewriting of the image to be displayed (S221: YES), the process proceeds to S22 in FIG. Then, by performing the processing of S22 to S26 as in the first embodiment, the image displayed on the display screen 3 is rewritten, and the process returns to S12 to detect touch input by the touch panel 253. On the other hand, if the processing defined in the icon instructed by touch input in S221 in FIG. 8 includes rewriting of an image or the like displayed on the sub display panel 252 (display screen 4) side (S221: NO) ), The process proceeds to S32 of FIG. Similarly, by performing the processes of S32 to S36, the image displayed on the display screen 4 is rewritten, and the process returns to S12, and the touch input is detected by the touch panel 253.

  As described above, the display device 201 according to the third embodiment can detect touch input performed from the display screen 4 side, but does not detect touch input from the display screen 3 side. That is, the substrate disposed on the display screen 3 side does not need to have flexibility. Therefore, since a substrate made of glass or the like can be used, the strength of the display medium 210 can be increased. In addition, since no contact sensor is used, the number of parts can be reduced.

  Note that the configurations of the display device and the display medium shown in the above embodiments are merely examples, and it goes without saying that the present invention can be modified in various ways. The contact sensors (infrared light emitting unit 11 and infrared light receiving unit 12) are provided on the main surface side (display screen 3 side) of the display media 10 and 110 in the first and second embodiments, but the back surface side (display screen 4). Side). Further, the contact sensor is not limited to an infrared sensor, but an ultrasonic sensor may be used, or a diaphragm or the like is provided on the main surface side to detect distortion caused by contact pressure of a finger or the like. May be.

  As an example of the contact position detection method using the touch panels 53, 153, and 253, in the first to third embodiments, the resistance film method and the surface capacitance method are given as examples, but other known detection methods are used. It may be adopted. For example, a projection capacitive method, a matrix resistive film method, an ultrasonic method, an infrared method, an electromagnetic induction method, and the like can be given.

  The main substrates 21, 121, and 221 and the film substrate 30 do not have to be light transmissive. In the first to third embodiments, examples of the display devices 1, 101, and 201 on which the display devices 10, 110, and 210 are mounted include electronic signboards used for display of electronic advertisements, display of electronic books, and the like. The electronic paper used for can be mentioned.

  In the third embodiment, the film substrate 25 of the display medium 210 shown in FIG. 7 is a film-like substrate made of the same PET as in the first embodiment and having light transparency and flexibility. For example, a substrate made of glass and having light transmittance may be used.

  In the second embodiment, ITO is exemplified as a material of the detection electrode 123 formed on the main substrate 121. However, the detection electrode 123 is formed using a material having higher resistivity such as zinc oxide or tin oxide. May be. In the first to third embodiments, the TP controller 71 periodically acquires the potential (divided value) of the detection electrode 23 from when the PEN_DOWN signal is output until the PEN_UP signal is output. Although the data is stored in the buffer and further A / D converted and output to the CPU 60, the output to the CPU 60 may be performed only once when the PEN_UP signal is output.

  In the above embodiment, the film substrate 25 corresponds to a “first substrate”, and the film substrate 32 corresponds to a “second substrate”. The main substrates 21, 121, and 221 correspond to the “third substrate”. The display layer 43 corresponds to a “first layer”, and the display layer 44 corresponds to a “second layer”. The film substrate 30 corresponds to a “fourth substrate”. The contact sensors (the infrared light emitting unit 11 and the infrared light receiving unit 12) correspond to the “first detection unit”. The detection electrode 125 corresponds to “second detection means”. The TP controller 71 in the second embodiment corresponds to “calculation means”.

DESCRIPTION OF SYMBOLS 1,101,201 Display apparatus 3,4 Display screen 10,110,210 Display medium 11 Infrared light emission part 12 Infrared light reception part 21,121,221 Main substrate 22 Pixel electrode 23,31,123,125 Detection electrode 25,30, 32 Film substrate 26, 33 Common electrode 41, 42 Charged particle 43, 44 Display layer 51, 151, 251 Main display panel 52, 152, 252 Sub display panel 53, 153, 253 Touch panel 60 CPU
71 TP controller

Claims (4)

A first substrate in which an electrode is formed on one side of a substrate having optical transparency;
An electrode is formed on one surface side of the substrate having optical transparency, and one surface of the second substrate is disposed to face one surface of the first substrate;
A third substrate disposed between and opposed to the first substrate and the second substrate;
A first layer disposed between the first substrate and the third substrate and including a plurality of charged particles;
A second layer disposed between the second substrate and the third substrate and including a plurality of charged particles;
A plurality of pixel electrodes formed on one surface side of the third substrate;
Detection for electrically detecting the position of an object formed on the other surface of the third substrate and in contact with or close to at least one of the other surface of the first substrate and the other surface of the second substrate Electrodes,
A display medium comprising: An electrode is formed on one surface side of the flexible substrate, and the one surface is opposed to the detection electrode with a predetermined gap between the detection electrode and the second layer. A fourth substrate disposed therebetween,
The display medium according to claim 1, wherein the second substrate is a substrate that is flexible and is disposed on the other surface side of the third substrate. It is disposed on at least one side of the other surface of the first substrate and the other surface of the second substrate, and makes an object contact or proximity to the other surface of the first substrate or the other surface of the second substrate. Further comprising first detecting means for detecting;
The display medium according to claim 2, wherein the first substrate and the third substrate are substrates having flexibility. It is disposed on at least one side of the other surface of the first substrate and the other surface of the second substrate, and makes an object contact or proximity to the other surface of the first substrate or the other surface of the second substrate. First detecting means for detecting;
A second detection means formed on the other surface side of the third substrate, electrically connected to the detection electrode, and detecting the contact position to the detection electrode;
The display medium according to claim 1, further comprising:
A calculation unit connected to the second detection unit of the display medium and performing a calculation for specifying the contact position detected by the second detection unit;
A display device comprising:

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