KR20110006539A - Electrophoretic display device having internal touch screen panel - Google Patents

Abstract

PURPOSE: An electrophoretic display device with an internal touch screen panel is provided to form an infrared ray filter by a single layer, thereby simplifying a process. CONSTITUTION: An image gate line and an image signal line cross each other on a substrate(110). An image switching TFT(120) is formed on the substrate. The image switching TFT is electrically connected to the image gate line and the image signal line. A sensing TFT is formed on the substrate.

Description

Electrophoretic display device having internal touch screen panel

The present invention relates to an electrophoretic display, and more particularly, to an electrophoretic display having a touch sensing function.

In general, a display device receives an image signal and displays an image, and includes a cathode ray tube display device, a liquid crystal display (LCD), an electrophoretic display, and the like.

The cathode ray tube display device includes a vacuum tube therein and emits an electron beam from an electron gun to display an image. The cathode ray tube display device must have a sufficient distance for the electron beam to rotate, and thus has a disadvantage of being thick and heavy. The liquid crystal display displays an image using the optical characteristics of the liquid crystal, and is thinner and lighter than the cathode ray tube display. However, since the backlight assembly for providing light to the liquid crystal should be provided, there is a limit to thinning and weight reduction.

The electrophoretic display displays an image using a phenomenon in which charged pigment particles move by an electric field formed between upper and lower substrates, that is, electrophoresis. The electrophoretic display is a reflective display device that displays an image using external light, and thus does not need to have a separate light source. Therefore, there is an advantage in that the thickness is thinner and lighter than the liquid crystal display device.

However, the conventional electrophoretic display device has only a display function, and thus, an electric characteristic is changed at a touch point that is attached to the display device and is in contact with a finger or a pen, thereby preventing a user interface function that detects the touch point.

The present invention has been made in an effort to provide a touch screen embedded electrophoretic display device using an infrared light sensor method.

In order to solve the above technical problem, a preferred embodiment of the electrophoretic display device according to the present invention comprises a substrate in which the image gate wiring and the image signal wiring is formed cross; An image switching TFT formed on the substrate and electrically connected to the image gate line and the image signal line; A sensing TFT formed on the substrate and configured to sense infrared rays and generate an infrared sensing signal; An output switching TFT formed on the substrate and connected to the sensing TFT to output position information from the infrared detection signal; An insulating film formed on the substrate to cover the image switching TFT, the sensing TFT, and the output switching TFT together; An infrared filter formed on the insulating layer as a single layer and transmitting only infrared rays; A pixel electrode formed on the infrared filter and electrically connected to the image switching TFT; An electrophoretic film formed on the pixel electrode and having a plurality of microcapsules including pigment particles positively and negatively charged; And a common electrode formed on the electrophoretic film.

In order to solve the above technical problem, another preferred embodiment of the electrophoretic display device according to the present invention includes a substrate in which the image gate wiring and the image signal wiring are formed to cross; An image switching TFT formed on the substrate and electrically connected to the image gate wiring and the image signal wiring; A sensing TFT formed on the substrate and configured to sense infrared rays and generate an infrared sensing signal; An output switching TFT formed on the substrate and connected to the sensing TFT to output position information from the infrared detection signal; An insulating film formed on the substrate to cover the image switching TFT, the sensing TFT, and the output switching TFT together; A pixel electrode formed on the insulating film and electrically connected to the image switching TFT; An infrared filter formed on the pixel electrode in a single layer and transmitting only infrared light; An electrophoretic film formed on the infrared filter and having a plurality of microcapsules including positive and negatively charged pigment particles; And a common electrode formed on the electrophoretic film.

According to the present invention, since the touch screen panel can be embedded inside the electrophoretic display device, there is no increase in weight due to the touch screen, and the touch screen is not exposed to the surface, and thus the surface is not damaged even when used for a long time. When the touch screen detects natural light in the visible light region, the recognition rate decreases when the place is dark or there is a shadow, but the present invention detects infrared rays, so the recognition rate is excellent because it is not limited to the use place or the surrounding brightness. In addition, since the infrared filter is formed as a single layer, the process is simple and it is possible to form the pixel electrode not only as a metallic material but also as a transparent conductive oxide (TCO), carbon nanotube, graphene, or the like. do.

Hereinafter, exemplary embodiments of a touch screen embedded electrophoretic display device according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you.

1 is a view showing a schematic configuration of a first embodiment of an electrophoretic display device according to the present invention.

Referring to FIG. 1, the electrophoretic display device 100 of the first embodiment includes a substrate 110, an image switching TFT 120, a sensing TFT 130, an output switching TFT 140, an insulating film 150, and an infrared filter. 155, a pixel electrode 160, an adhesive 165, an electrophoretic film 170, a common electrode 180, and an upper plate 190.

The substrate 110 may have an insulating material and a high melting point material, but a material having flexibility and insulation may be used. Glass, sapphire, quartz, etc. may be used as the substrate having an insulating property and a high melting point, and a metal plate with an insulating film, Si, GaAs, InP, etc. with an insulating film may be used. Substrates made of flexible and insulating materials may be made of plastics such as PET, PC, AryLite, or very thin Si, GaAs, InP, metal foil, or the like having an insulating film. The image gate wiring (not shown) and the image signal wiring (not shown) intersect each other on the substrate 110. The cell region is defined by the intersection of the image gate line and the image signal line.

The image switching TFT 120 is formed on the substrate 110, and the image switching gate electrode 121, the image switching gate insulating film 122, the image switching channel region 123, the image switching source region 124 and the image switching The drain region 125 is provided. The image switching gate electrode 121 is made of a conductive material and electrically connected to the image gate wiring. The image switching gate insulating layer 123 is formed of an insulating material so as to cover the image switching gate electrode 121. The image switching channel region 123 is formed on the image switching gate insulating layer 123 and is made of amorphous silicon or polycrystalline silicon. The image switching source region 124 and the image switching drain region 125 are formed to cover a portion of the image switching channel region 123, respectively, and are formed opposite to the image switching gate electrode 121. The image switching source region 124 is electrically connected to the image signal wiring, and the image switching drain region 125 is electrically connected to the pixel electrode 160 to switch the image signal voltage to the pixel electrode 160.

The sensing TFT 130 is formed on the substrate 110 and detects infrared rays to generate an infrared detection signal. The sensing TFT 130 includes a sensing gate electrode 131, a sensing gate insulating layer 132, a sensing channel region 133, a sensing source region 134, and a sensing drain region 135. The sensing gate electrode 131 is made of a conductive material and is electrically connected to an off voltage line (not shown). The sensing gate insulating layer 132 is formed of an insulating material so as to cover the sensing gate electrode 131. The sensing channel region 133 is formed on the sensing gate insulating layer 132 and is made of a material capable of absorbing light having an infrared wavelength. To this end, the sensing channel region 133 may be made of polycrystalline silicon, single crystal silicon, InSb, Ge, InAs, InGaAs, CdTe, CdSe, GaAs, GaInP, InP, AlGaAs, and combinations thereof. The sensing source region 134 and the sensing drain region 135 are formed to cover a portion of the sensing channel region 133, respectively, and are formed opposite to the sensing gate electrode 131. The sensing source region 134 is electrically connected to a power line (not shown), and the sensing drain region 135 is electrically connected to a storage capacitor (not shown) for storing an infrared sensing signal. The storage capacitor for storing the infrared sensing signal charges the charges of the increased leakage current when the channel region 133 of the sensing TFT 130 absorbs the infrared rays.

The output switching TFT 140 is formed on the substrate 110, and the output switching gate electrode 141, the output switching gate insulating film 142, the output switching channel region 143, the output switching source region 144 and the output switching The drain region 145 is provided. The output switching gate electrode 141 is made of a conductive material and electrically connected to the sensing gate wiring (not shown). The output switching gate insulating layer 142 is formed of an insulating material so as to cover the output switching gate electrode 141. The output switching channel region 143 is formed on the output switching gate insulating layer 142 and is made of amorphous silicon or polycrystalline silicon. The output switching source region 144 and the output switching drain region 145 are formed to cover a portion of the output switching channel region 143, respectively, and are formed opposite to the output switching gate electrode 141. The output switching source region 144 is electrically connected to the storage capacitor for storing the infrared sensing signal, and the output switching drain region 145 is electrically connected to the output wiring (not shown). That is, the output switching TFT 140 is electrically connected to the sensing TFT 130 through the storage capacitor for storing the infrared sensing signal, and outputs position information from the infrared sensing signal generated from the sensing TFT 130.

The gate insulating layers 122, 132, and 142 provided in the image switching TFT 120, the sensing TFT 130, and the output switching TFT 140 may be integrally formed as illustrated in FIG. 1. The channel regions 123, 133, and 143 provided in the image switching TFT 120, the sensing TFT 130, and the output switching TFT 140, respectively, are all formed of amorphous silicon, and then the channel region of the sensing TFT 130 is formed. Only 133 can be crystallized from polycrystalline silicon. When the channel region 133 of the sensing TFT 130 is crystallized, a low temperature polycrystalline silicon (LTPS) process is used when the substrate 110 is a glass substrate, and a high temperature polycrystal when the substrate 110 is capable of a high temperature process. Silicon (HTPS) processes can be used. LTPS and HTPS are well known processes and will not be described here.

The insulating layer 150 is formed on the substrate 110 and is formed to cover the image switching TFT 120, the sensing TFT 130, and the output switching TFT 140 together. Since the electrophoretic display device 100 of the first embodiment has a reflective structure, the insulating film 150 does not have to be made of a transparent organic material unlike a conventional liquid crystal display device.

The infrared filter 155 transmits only infrared rays and does not transmit light having a wavelength other than infrared rays. The infrared filter 155 is formed as a single layer on the insulating layer 150. The infrared filter 155 is made of at least one material selected from the group consisting of chromium oxide (CrO, Cr ₂ O ₃ ) and manganese oxide (MnO, Mn ₃ O ₄ , Mn ₂ O ₃ , MnO ₂ , Mn ₂ O ₇ ) It may be made of a single layer thin film. As such, when the infrared filter 155 is formed of a single layer thin film, the process may be simplified as compared with the case of forming the infrared filter 155 as a composite layer.

The pixel electrode 160 is formed in the unit pixel area on the outlier filter 155. In addition, a contact hole is formed in the insulating layer 150 and the infrared filter 155 to expose a portion of the drain region 125 of the image switching TFT 120. The pixel electrode 160 extends into the contact hole to extend the image switching TFT ( It is electrically connected to the drain region 125 of 120. Through this, the image switching TFT 120 switches the pixel voltage to the pixel electrode 160. The pixel electrode 160 may be formed of a material that reflects light to serve as a light blocking film for the image switching TFT 120 and the output switching TFT 140. In addition, a through hole 163 penetrating the upper and lower surfaces of the pixel electrode 160 may be formed in the pixel electrode 160 to allow infrared rays to enter the sensing TFT 130. The through hole 163 is disposed above the sensing TFT 130.

The upper plate 190 is disposed to face the substrate 110 to face the pixel electrode 160. The upper plate 190 may be made of a flexible plastic, an easily bent base film, or a metal having flexibility, and preferably PET.

The common electrode 180 is formed on the lower side of the upper plate 190 and may be made of a transparent conductive material that transmits light. To this end, the common electrode 180 may be formed of indium tin oxide (ITO), al-doped zinc oxide (AZO), indium zinc oxide (IZO), carbon nanotubes, graphene, and combinations thereof. .

The electrophoretic film 170 is formed on the lower side of the common electrode 180 and includes a plurality of microcapsules 171. The microcapsules 171 may have a ball shape having a size of several hundred micrometers and include positively charged pigment particles 172 and negatively charged pigment particles 173. Positively charged pigment particles 172 and negatively charged pigment particles 173 are mixed in a transparent fluid 174. Each of the pigment particles 172 is separated according to the electric field directions of the common electrode 180 and the pixel electrode 160. Since the pigment particles 172 exhibit bistable properties, they remain intact even when the electric field disappears. Can be.

Positively charged pigment particles 172 and negatively charged pigment particles 173 may exhibit black and white or color. When the positively charged pigment particles 172 and the negatively charged pigment particles 173 exhibit black and white, as shown in FIG. 1, the negatively charged pigment particles 173 are black pigment particles. The charged pigment particles 172 may be white pigment particles. In this case, when the black pigment particles 173 are separated in the direction of the common electrode 180, external light incident through the common electrode 180 is reflected by the electrophoretic film 170 to realize black color, and white pigment particles 172. Is separated in the direction of the common electrode 180, white is implemented.

A protective layer (not shown) may be formed on both sides of the electrophoretic film 170 to block the flow of the microcapsule 171 and to protect the microcapsule 171.

The adhesive 165 is attached to the lower surface of the electrophoretic film 170 to bond the pixel electrode 160 and the electrophoretic film 170 through a laminating process.

2 is a view showing a schematic configuration of a second embodiment of an electrophoretic display device according to the present invention.

Referring to FIG. 2, the electrophoretic display 200 of the second embodiment includes a substrate 110, an image switching TFT 120, a sensing TFT 130, an output switching TFT 140, an insulating film 150, and an infrared filter. 255, a pixel electrode 260, an adhesive 165, an electrophoretic film 170, a common electrode 180, and an upper plate 190.

The substrate 110, the image switching TFT 120, the sensing TFT 130, the output switching TFT 140, the insulating film 150, the infrared filter 255, which are provided in the electrophoretic display 200 of the second embodiment, The pixel electrode 260, the adhesive 165, the electrophoretic film 170, the common electrode 180, and the upper plate 190 may include a substrate 110 and an image provided in the electrophoretic display device 100 of the first embodiment. Switching TFT 120, sensing TFT 130, output switching TFT 140, insulating film 150, infrared filter 155, pixel electrode 160, adhesive 165, electrophoretic film 170, common electrode Corresponding to the 180 and the upper plate 190, respectively.

However, the pixel electrode 260 of the second embodiment may be made of a material that transmits light, not a material that blocks light. That is, the pixel electrode 260 may be formed of at least one selected from indium tin oxide (ITO), al-doped zinc oxide (AZO), indium zinc oxide (IZO), carbon nanotubes, and graphene. This is because the infrared filter 255 is not formed of a composite layer using constructive interference and destructive interference, but is formed of a single layer thin film, and thus it is possible to form a transparent electrode on the infrared filter 255.

Since the pixel electrode 260 is made of a transparent material, unlike the first embodiment, a separate through hole does not need to be formed in the pixel electrode 260 of the second embodiment. However, since the pixel electrode 260 is made of a transparent material, in addition to the sensing TFT 130, the image switching TFT 120 and the output switching TFT 140 are also exposed to infrared rays. Therefore, it is preferable that the image switching channel region 123 provided in the image switching TFT 120 and the output switching channel region 143 provided in the output switching TFT 140 are made of a material that does not absorb infrared rays to prevent malfunction. . Accordingly, the image switching channel region 123 and the output switching channel region 143 may be made of amorphous silicon that does not absorb infrared rays. In addition, since the sensing channel region 133 provided in the sensing TFT 130 must absorb infrared rays, the sensing channel region 133 may be made of polycrystalline silicon.

As described above, in the case of the second embodiment, since the transparent conductive material is used as the pixel electrode 260, there is no need for a separate through hole, so that the process of forming the through hole can be omitted.

3 is a view showing a schematic configuration of a third embodiment of an electrophoretic display device according to the present invention.

Referring to FIG. 3, the electrophoretic display device 300 of the third embodiment includes a substrate 110, an image switching TFT 120, a sensing TFT 130, an output switching TFT 140, an insulating film 150, and a pixel electrode. 360, an infrared filter 355, an adhesive 165, an electrophoretic film 170, a common electrode 180, and an upper plate 190.

The substrate 110 may have an insulating material and a high melting point material, but a material having flexibility and insulation may be used. Glass, sapphire, quartz, etc. may be used as the substrate made of a material having high melting point, and also a metal plate having an insulating film, Si, GaAs, and InP having an insulating film may be used. Substrates made of flexible and insulating materials may be made of plastics such as PET, PC, AryLite, or very thin Si, GaAs, InP, metal foil, or the like having an insulating film. The image gate wiring (not shown) and the image signal wiring (not shown) intersect each other on the substrate 110. The cell region is defined by the intersection of the image gate line and the image signal line.

The image switching TFT 120 is formed on the substrate 110, and the image switching gate electrode 121, the image switching gate insulating film 122, the image switching channel region 123, the image switching source region 124 and the image switching The drain region 125 is provided. The image switching gate electrode 121 is made of a conductive material and electrically connected to the image gate wiring. The image switching gate insulating layer 123 is formed of an insulating material so as to cover the image switching gate electrode 121. The image switching channel region 123 is formed on the image switching gate insulating layer 123. Since the pixel electrode 360 to be described later is made of a transparent material, the image switching channel region 123 is made of a material that does not absorb infrared rays. It is preferably made of amorphous silicon. The image switching source region 124 and the image switching drain region 125 are formed to cover a portion of the image switching channel region 123, respectively, and are formed opposite to the image switching gate electrode 121. The image switching source region 124 is electrically connected to the image signal wiring, and the image switching drain region 125 is electrically connected to the pixel electrode 360 to switch the image signal voltage to the pixel electrode 360.

The sensing TFT 130 is formed on the substrate 110 and detects infrared rays to generate an infrared detection signal. The sensing TFT 130 includes a sensing gate electrode 131, a sensing gate insulating layer 132, a sensing channel region 133, a sensing source region 134, and a sensing drain region 135. The sensing gate electrode 131 is made of a conductive material and is electrically connected to an off voltage line (not shown). The sensing gate insulating layer 132 is formed of an insulating material so as to cover the sensing gate electrode 131. The sensing channel region 133 is formed on the sensing gate insulating layer 132 and is made of a material capable of absorbing light having an infrared wavelength. To this end, the sensing channel region 133 may be made of polycrystalline silicon, single crystal silicon, InSb, Ge, InAs, InGaAs, CdTe, CdSe, GaAs, GaInP, InP, AlGaAs, and combinations thereof. It is preferably made of polycrystalline silicon. The sensing source region 134 and the sensing drain region 135 are formed to cover a portion of the sensing channel region 133, respectively, and are formed opposite to the sensing gate electrode 131. The sensing source region 134 is electrically connected to a power line (not shown), and the sensing drain region 135 is electrically connected to a storage capacitor (not shown) for storing an infrared sensing signal. The storage capacitor for storing the infrared sensing signal charges the charges of the increased leakage current when the channel region 133 of the sensing TFT 130 absorbs the infrared rays.

The output switching TFT 140 is formed on the substrate 110, and the output switching gate electrode 141, the output switching gate insulating film 142, the output switching channel region 143, the output switching source region 144 and the output switching The drain region 145 is provided. The output switching gate electrode 141 is made of a conductive material and electrically connected to the sensing gate wiring (not shown). The output switching gate insulating layer 142 is formed of an insulating material so as to cover the output switching gate electrode 141. The output switching channel region 143 is formed on the output switching gate insulating layer 142. Since the pixel electrode 360 to be described later is made of a transparent material, the output switching channel region 143 is made of a material that does not absorb infrared rays. It is preferably made of amorphous silicon. The output switching source region 144 and the output switching drain region 145 are formed to cover a portion of the output switching channel region 143, respectively, and are formed opposite to the output switching gate electrode 141. The output switching source region 144 is electrically connected to the storage capacitor for storing the infrared sensing signal, and the output switching drain region 145 is electrically connected to the output wiring (not shown). That is, the output switching TFT 140 is electrically connected to the sensing TFT 130 through the storage capacitor for storing the infrared sensing signal, and outputs position information from the infrared sensing signal generated from the sensing TFT 130.

The gate insulating layers 122, 132, and 142 provided in the image switching TFT 120, the sensing TFT 130, and the output switching TFT 140 may be integrally formed as illustrated in FIG. 3. The channel regions 123, 133, and 143 provided in the image switching TFT 120, the sensing TFT 130, and the output switching TFT 140, respectively, are all formed of amorphous silicon, and then the channel region of the sensing TFT 130 is formed. Only 133 can be crystallized from polycrystalline silicon. When the channel region 133 of the sensing TFT 130 is crystallized, a low temperature polycrystalline silicon (LTPS) process is used when the substrate 110 is a glass substrate, and a high temperature polycrystal when the substrate 110 is capable of a high temperature process. Silicon (HTPS) processes can be used. LTPS and HTPS are well known processes and will not be described here.

The insulating layer 150 is formed on the substrate 110 and is formed to cover the image switching TFT 120, the sensing TFT 130, and the output switching TFT 140 together. Since the electrophoretic display 300 of the third exemplary embodiment has a reflective structure, the insulating layer 150 does not have to be made of a transparent organic material unlike a conventional liquid crystal display.

The pixel electrode 360 is formed in the unit pixel area on the insulating layer 150. In addition, a contact hole is formed in the insulating layer 150 to expose a portion of the drain region 125 of the image switching TFT 120, and the pixel electrode 360 extends into the contact hole so that the drain region of the image switching TFT 120 is formed. 125) is electrically connected. As a result, the image switching TFT 120 switches the pixel voltage to the pixel electrode 360. Like the second embodiment, the pixel electrode 360 may be made of a material that transmits light, not a material that blocks light. That is, the pixel electrode 360 may be formed of at least one selected from indium tin oxide (ITO), al-doped zinc oxide (AZO), indium zinc oxide (IZO), carbon nanotubes, and graphene. Since the pixel electrode 360 is made of a transparent material, unlike the first embodiment, a separate through hole does not need to be formed in the pixel electrode 360 of the third embodiment.

The infrared filter 355 transmits only infrared rays and does not transmit light having a wavelength other than infrared rays, and is formed as a single layer on the pixel electrode 360. The infrared filter 355 is one or more materials selected from the group consisting of chromium oxide (CrO, Cr ₂ O ₃ ) and manganese oxide (MnO, Mn ₃ O ₄ , Mn ₂ O ₃ , MnO ₂ , Mn ₂ O ₇ ) It may be made of a single layer thin film.

The upper plate 190 is disposed to face the substrate 110 to face the infrared filter 355. The upper plate 190 may be made of a flexible plastic, an easily bent base film, or a metal having flexibility, and preferably PET.

The common electrode 180 is formed on the lower side of the upper plate 190 and may be made of a transparent conductive material that transmits light. To this end, the common electrode 180 may be formed of indium tin oxide (ITO), al-doped zinc oxide (AZO), indium zinc oxide (IZO), carbon nanotubes, graphene, and combinations thereof. .

The electrophoretic film 170 is formed on the lower side of the common electrode 180 and includes a plurality of microcapsules 171. The microcapsules 171 may have a ball shape having a size of several hundred micrometers and include positively charged pigment particles 172 and negatively charged pigment particles 173. Positively charged pigment particles 172 and negatively charged pigment particles 173 are mixed in a transparent fluid 174. Each of the pigment particles 172 is separated according to the electric field directions of the common electrode 180 and the pixel electrode 360. Since the pigment particles 172 exhibit bistable characteristics, they remain intact even when the electric field disappears. Can be.

Positively charged pigment particles 172 and negatively charged pigment particles 173 may exhibit black and white or color. When the positively charged pigment particles 172 and the negatively charged pigment particles 173 exhibit black and white, the negatively charged pigment particles 173 are black pigment particles, as shown in FIG. 3. The charged pigment particles 172 may be white pigment particles. In this case, when the black pigment particles 173 are separated in the direction of the common electrode 180, external light incident through the common electrode 180 is reflected by the electrophoretic film 170 to realize black color, and white pigment particles 172. Is separated in the direction of the common electrode 180, white is implemented.

A protective layer (not shown) may be formed on both sides of the electrophoretic film 170 to block the flow of the microcapsule 171 and to protect the microcapsule 171.

The adhesive 165 is attached to the lower surface of the electrophoretic film 170 to bond the infrared filter 355 and the electrophoretic film 170 through a laminating process.

In the third embodiment, since the infrared filter 355 is formed of a single layer thin film, the process is simpler than the case of forming an infrared filter with a composite layer, and since the transparent conductive material is used as the pixel electrode 360, There is an advantage that the through hole of the need not to be omitted so that the process of forming the through hole can be omitted.

4 is a circuit diagram illustrating an image display process and a sensing process of an electrophoretic display device according to the present invention.

First, an image display process of the electrophoretic display device 100, 200, 300 according to the present invention will be described.

Referring to FIGS. 1 to 4, in the image display, the voltage of the channel region 123 of the image switching TFT 120 is applied to the image gate wiring at the time when the pixel is selected, and thus the channel of the image switching TFT 120 is applied. As the region 123 is opened, an image signal voltage is simultaneously applied to the image signal wiring and transferred to the pixel electrodes 160, 260, and 360. When the pixel is not selected, a voltage is applied to the image gate wiring to close the channel region 123 of the image switching TFT 120, and the channel region 123 of the image switching TFT 120 is closed, thereby closing the pixel. The image signal voltage transmitted to the electrodes 160, 260, 360 is cut off. Therefore, there is no interference of image information of the pixel. In this way, the voltage is switched on the pixel electrodes 160, 260, 360 to display an image in a manner in which external light is reflected.

The capacitor denoted by reference numeral 220 corresponds to a capacitor generated by the pixel electrodes 160, 260, and 360 and the common electrode 180. The capacitor denoted by reference numeral 230 is a pixel charge storage capacitor that is a capacitor for preventing the voltage applied to the pixel from being changed by the leakage current of the image switching TFT 120 during the time when the pixel is not selected.

Next, the sensing process of the electrophoretic display device 100, 200, 300 according to the present invention will be described.

Referring to FIGS. 1 to 4, first, an infrared ray is irradiated to a specific area of the electrophoretic display device 100, 200, 300 while being in contact with the electrophoretic display device 100, 200, 300 through an infrared pen 195 or the like. Incident. The incident infrared rays are incident on the sensing TFT 130. In the electrophoretic display device 100 of the first exemplary embodiment, infrared light emitted from the infrared pen 195 is incident on the sensing TFT 130 through the through hole 163 and the infrared filter 155. In the electrophoretic display 200 of the second exemplary embodiment, the infrared light emitted from the infrared pen 195 is incident on the sensing TFT 130 via the transparent pixel electrode 260 and the infrared filter 255. In the electrophoretic display 300 of the third exemplary embodiment, infrared light emitted from the infrared pen 195 is incident on the sensing TFT 130 through the infrared filter 355 and the transparent pixel electrode 360. Since the infrared rays emitted from the infrared pen 195 are incident on the sensing TFT 130 through the infrared filters 155, 255, and 355 in all of the first, second, and third embodiments, light having a wavelength other than infrared is sensed. ), The sensing TFT 130 is prevented from malfunctioning.

When the infrared ray is incident on the sensing TFT 130, the infrared ray is absorbed through the channel region 133 of the sensing TFT 130 made of a material capable of absorbing infrared rays. The gate electrode 131 of the sensing TFT 130 is connected to the off-voltage wiring in which the channel region 133 is not opened, and thus the channel region 133 is always closed unless infrared rays are absorbed. However, when the channel region 133 of the sensing TFT 130 absorbs infrared rays, the channel region 133 is partially opened to increase the leakage current of the sensing TFT 130. When the leakage current of the sensing TFT 130 increases, charges are charged in the storage capacitor for storing the infrared sensing signal indicated by reference numeral 210. Charging of the storage capacitor 210 for storing the infrared sensing signal occurs over the entire frame time.

While the charge is charged in the storage capacitor 210 for storing the infrared sensing signal, the channel region 143 of the output switching TFT 140 is connected to the sensing gate wiring electrically connected to the gate electrode 141 of the output switching TFT 140. This unopened off voltage is applied. However, the on-voltage at which the channel region 143 of the output switching TFT 140 is applied to the sensing gate wiring at a selection time is applied to switch the output switching TFT 140 to be stored in the storage capacitor 210 for storing the infrared sensing signal. Since the electric charge flows along the output wiring, the position detection unit (not shown) can read the electric charge to determine the position information where the infrared ray is incident. And accordingly, a predetermined operation is performed.

Although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific preferred embodiments described above, and the present invention belongs to the present invention without departing from the gist of the present invention as claimed in the claims. Various modifications can be made by those skilled in the art, and such changes are within the scope of the claims.

1 is a view showing a schematic configuration of a first embodiment of an electrophoretic display device according to the present invention.

2 is a view showing a schematic configuration of a second embodiment of an electrophoretic display device according to the present invention.

3 is a view showing a schematic configuration of a third embodiment of an electrophoretic display device according to the present invention.

4 is a circuit diagram illustrating an image display process and a sensing process of an electrophoretic display device according to the present invention.

Claims (8)

A substrate on which the image gate line and the image signal line cross each other; An image switching TFT formed on the substrate and electrically connected to the image gate line and the image signal line; A sensing TFT formed on the substrate and configured to sense infrared rays and generate an infrared sensing signal; An output switching TFT formed on the substrate and connected to the sensing TFT to output position information from the infrared detection signal; An insulating film formed on the substrate to cover the image switching TFT, the sensing TFT, and the output switching TFT together; An infrared filter formed on the insulating layer as a single layer and transmitting only infrared rays; A pixel electrode formed on the infrared filter and electrically connected to the image switching TFT; An electrophoretic film formed on the pixel electrode and having a plurality of microcapsules including pigment particles positively and negatively charged; And Electrophoretic display device comprising a; common electrode formed on the electrophoretic film. A substrate on which the image gate line and the image signal line cross each other; An image switching TFT formed on the substrate and electrically connected to the image gate line and the image signal line; A sensing TFT formed on the substrate and configured to sense infrared rays and generate an infrared sensing signal; An output switching TFT formed on the substrate and connected to the sensing TFT to output position information from the infrared detection signal; An insulating film formed on the substrate to cover the image switching TFT, the sensing TFT, and the output switching TFT together; A pixel electrode formed on the insulating film and electrically connected to the image switching TFT; An infrared filter formed on the pixel electrode in a single layer and transmitting only infrared light; An electrophoretic film formed on the infrared filter and having a plurality of microcapsules including positive and negatively charged pigment particles; And Electrophoretic display device comprising a; common electrode formed on the electrophoretic film. The method according to claim 1 or 2, The infrared filter is a single material consisting of at least one material selected from the group consisting of chromium oxide (CrO, Cr ₂ O ₃ ) and manganese oxide (MnO, Mn ₃ O ₄ , Mn ₂ O ₃ , MnO ₂ , Mn ₂ O ₇ ) Electrophoretic display device characterized in that the layer thin film. The method according to claim 1 or 2, The pixel electrode is made of a material that reflects light to serve as a light blocking film for the image switching TFT and the output switching TFT, And a through hole penetrating an upper surface and a lower surface of the pixel electrode, wherein the through hole is formed on the sensing TFT to allow infrared rays to enter the sensing TFT. The method of claim 4, wherein The channel region of the sensing TFT is at least one selected from polycrystalline silicon, single crystal silicon, InSb, Ge, InAs, InGaAs, CdTe, CdSe, GaAs, GaInP, InP and AlGaAs. The method according to claim 1 or 2, The pixel electrode is made of a conductive material that transmits light. And a channel region of the image switching TFT and an output switching TFT is made of amorphous silicon, and the channel region of the sensing TFT is made of polycrystalline silicon. The method of claim 6, The pixel electrode may include at least one selected from indium tin oxide (ITO), al-doped zinc oxide (AZO), indium zinc oxide (IZO), carbon nanotubes, and graphene. Device. The method according to claim 1 or 2, The common electrode is an electrophoretic display comprising at least one selected from indium tin oxide (ITO), al-doped zinc oxide (AZO), indium zinc oxide (IZO), carbon nanotubes, and graphene. Device.

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