TECHNICAL FIELD
[0001] The disclosed subject matter relates to a digital smart paper, more particularly the disclosed subject matter relates to a digital smart paper that is configured to display different content on both sides of the digital smart paper.
BACKGROUND
[0002] With advent of technology, more and more people have started using handheld communication devices for reading as well as communication purposes. However, commonly available electronic display & communication devices have limitations in terms of readability of content being displayed for long hours, and handling of such devices. Huge amount of power & backlight to drive display pixels integrated with different chips and modules make it expensive, bulky, non-flexible, limiting various applications and mobility; the display is a passive device with the intelligence residing on an external system and is integrated with flat serial interface. Specifically, to address this problem, electrophoresis technology based displays integrated with printed organic electronics on a single flexible plastic substrate as thin as a paper are being developed to realize intelligent image print & display functionality.
[0003] Various electrophoretic display devices are known conventionally. One such device has been disclosed in published US patent publication no. 20150138736. Particularly, the patent discloses a flexible electronic reading device. The device includes a flexible display part and a handle part in order to house the electronics to make the electronic reading device function. The reading device also includes a flexible backplane. However, this device is not 100% flexible as some of the inflexible electronics are housed
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within the handle like microcontroller etc. Also, the substrate of the flexible backplane extends beyond the border of its display. This provides a display device with a smaller display to a user of the reading device with display also being limited to only on one side of the reading device. [0004] In another US granted patent no. 8362488, a flexible backplane device is provided. The display is mounted on this flexible plane. However, the flexible backplane provided in the patent does not disclose a standalone device per se. The interface electronics are not integrated to the display device. Also, there is a single display side for such kind of device.
[0005] Furthermore, the known electrophoretic displays are generally integrated with rigid – Printed circuit Board plane and solid semiconductor based micro controller or electronics, thereby limiting the display from having conformal form factors and limited commercial applications. Also, in such displays, the image is static.
[0006] In view of the foregoing, there exists a need for an electrophoretic display device that obviates the various disadvantages of the conventional electrophoretic devices, as discussed. Particularly, there exists a need for an electrophoretic device that provides a desirable experience to the users.
SUMMARY
[0007] In an embodiment of the invention, there is provided a digital smart paper device wherein the digital smart paper device includes a base middle plane. The base middle plane is made up of a flexible material like plastic, etc. The smart paper further includes a
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display that is placed over both sides of base middle plane. It further includes an interface electronics required to run the display device. The display is configured in a way that both the sides of the display show a document in a continuous manner. For e.g. like a newspaper, book, etc.
[0008] In another embodiment of the invention, there is provided a method for manufacturing a digital smart paper device. The method includes providing a flexible base middle plane. The method further includes placing an interface electronics layer on both sides of the flexible base middle plane. The method further includes placement of a pixel array layer on each of the interface electronics layer. Furthermore, the method includes placing a display layer on each of the pixel array layer such that together both the display layers are configured to display the content in continuity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The disclosed subject matter of the present application will now be described in more detail with reference to exemplary embodiments of the apparatus and method, given by way of example, and with reference to the accompanying drawings, in which:
[0010] FIG. 1 illustrates an exemplary flexible display device according to an embodiment of the invention.
[0011] FIG. 2a illustrates an exemplary exploded view of internal components according to an embodiment of the invention.
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[0012] FIG. 2b illustrates a block diagram of interface electronics according to an embodiment of the invention.
[0013] FIG. 3 illustrates an exemplary view of the various layers of the smart paper according to an embodiment of the invention.
[0014] FIG. 4 illustrates the cross-sectional view of the various device layers according to an embodiment of the invention.
[0015] FIG. 5 illustrates pixel array arrangement of the display according to an embodiment of the invention.
[0016] FIG. 6 illustrates internal electronics in a single pixel array.
[0017] FIG. 7 illustrates a flow chart depicting a method of manufacturing a digital smart paper device according to an embodiment of the invention.
DETAILED DESCRIPTION
[0018] A few inventive aspects of the disclosed embodiments are explained in detail below with reference to the various figures. Exemplary embodiments are described to illustrate the disclosed subject matter, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a number of equivalent variations of the various features provided in the description that follows.
[0019] Referring to FIG. 1, illustrates a top view of a digital smart paper device 100 in accordance with an embodiment of the present invention. As shown in Fig. 1, the digital smart paper device 100 includes a display 102 using electrophoresis technology. The
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display 102 may include one or more layers, as will be explained later, configured on a middle plane (not shown). In an embodiment of the present invention, the display is monochromatic based on encapsulated electrophoretic medium employed. This allows pixel wise activation using thin film transistor (TFT) active matrix platform. In another embodiment, the display and the entire digital smart paper device 100 may be made flexible such that it can be rolled off, relying on the plastic electronics middle plane. The display 102 includes a control button 1022 for carrying out customized tasks, such as operating the menu for previous and forward stored image and switching the display 102 OFF or ON. The electrophoretic material used in the digital smart paper device 100 is bi stable and is excited by electrical trigger. The operation of the display 102 is controlled using a microcontroller. In an embodiment of the present invention, the display 102 is non-reflective, making it visible in active sunlight and require no backlight for displaying content.
[0020] The digital smart paper device 100 will be temporary and tuned to stay without any refreshment drive for a period of 30 – 40 minutes (known as Frame Time) depending on the size and resolution of the digital smart paper device 100 and various underpinning organic semiconductor materials electrical and mechanical characteristics. The refreshment time period of 30 – 40 minutes is adjusted by choosing proper middle plane circuit design and capacitor. The capacitor plays an important role in two aspects; one is to provide immediate desired power to the electrode for switching purpose and hold the potential for proper biasing along the electrode. A capacitor with high K dielectric material that is compatible with the flexible smart paper device 100 is chosen to achieve the above mentioned functionality.
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[0021] Now referring to FIG. 2a that illustrates an exploded view of the digital smart paper device 100. The digital smart paper device 100 includes a flexible middle plane 104. The flexible middle plane 104 may be formed from a plastic such as polyethyleneterephthalate (PET) or polyethelenemaphthalene (PEN) on which is fabricated a thin layer of organic active matrix pixel circuitry. The circuitry may comprise an array of organic (or inorganic) thin film transistors (TFTs). Broadly speaking in embodiments the flexible middle plane 104 is fabricated using solution based techniques patterned by, for example, direct-right printing, laser ablation or photolithography to fabricate the thin film transistors. The flexible middle plane 104 includes interface electronics on both sides of the flexible middle plane 104, wherein the electronic units communicate with each other. This will be explained in detail while describing FIG. 2b.
[0022] Still referring to FIG. 2a, the digital smart paper device 100 further contains a pixel array layer 106a, and 106b each on both sides of the flexible middle plane 104. Further, the digital smart paper device 100 includes a display layer 102a and 102b each mounted over the pixel array layers 106a, and 106b i.e. on both sides of the digital smart paper device 100. In an embodiment of the invention, the display layer 102a, and 102b could be an electrophoretic display, a bistable display, an e-ink display, an e-digital paper display, or any other flexible display component. The display layers 102a, and 102b mounted over the flexible middle plane 104 may be of exact size as of the middle plane 104. Therefore, the dimensions of the middle plane 104 and the display 102 are same. Hence, the digital smart paper device 100 gives a double sided display look and feel. In an embodiment of the invention, the two sides of the display may display a continuous content. For e.g. a newspaper, a book etc.
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[0023] Now referring to FIG. 2b the flexible middle plane104 includes a flexible circuit board with printed electronics 108. In an embodiment of the invention, the flexible circuit board with printed electronics could also be an integrated circuit. An adhesive layer connects the flexible circuit board with printed electronics 108 to the flexible middle plane104. The flexible circuit board with printed electronics 108 holds electronics for running and making the digital smart paper device 100 a standalone device. The electronics include a flexible battery 110 that can be rechargeable. In an embodiment of the invention the flexible battery 110 may be a printed flexible material battery of polymer or printed super capacitor based smart paper technology. This is to make the flexible battery 110 to be efficient in quick charging and discharging cycle, so as to enable high yield rate and accommodate the high mobility of OTFT electronics and ensure appropriate driving voltage for the organic electronics for standalone display of stored content, even when it is away from any paired wireless device. The flexible middle plane104 further includes a secondary charging unit 112 that may be a solar or a kinetic sensor for charging the flexible battery 110.. There is also present a display and control unit 114 to control the display of images etc. on the flexible display 102. The flexible circuit board with printed electronics 108 further includes an in situ programmable identity register 116. There is also provided a flexible printed non-volatile memory 118. The non-volatile memory 118 is configured to store images displayed on the flexible display 102. The digital smart paper device 100 may include a switch (not shown here) in order to recall previous images displayed that have been displayed on the flexible display 102.
[0024] Still referring to FIG. 2b, the flexible circuit board with printed electronics 108 further includes a flexible microcontroller 120 in order to control various functions of
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the digital smart paper device 100. In an embodiment of the invention, the microcontroller 120 is a fabricated using flexible material to render flexibility to the microcontroller 120. The microcontroller 120 is equipped with a program control code to provide in situ identity credentials to the digital smart paper device 100. The program control code is able to generate a unique device ID that is required to authenticate the digital smart paper device 100 wherein the digital smart paper device 100 has to communicate with other wireless devices. Hence, this would provide a more secure data communication between the digital smart paper device 100 and any of the wireless device. The microcontroller 120 is configured to perform the image transformation or encoding that is in order to accommodate the display resolution or pixel array and also determine the layout of the display content on the same display area. When the digital smart paper device 100 comes in sensor communication with another wireless device, it realizes the form factors of the wireless device. Hence, the program control code of the microcontroller 120 of the digital smart paper device 100 can then make the wireless device to change the specification of the content to be transferred for display, according to the specifications of the digital smart paper device 100. For. e.g. if a wireless host device transmits a document in an encoded format recognizable to communication protocol between the digital smart paper device 100 and a wireless host device, the microcontroller 120 decodes and lays out the document as per the encoding algorithm to be represented on the display 102 of the digital smart paper device 100. To achieve this functionality, the wireless device may be required to have encoding capabilities to match the digital smart paper device 100. There can also be an image transformation software or application provided to achieve this.
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[0025] Also, the digital smart paper device 100 communicates with another wireless device that is pre authenticated. It triggers the wireless device to format content that needs to be displayed in a certain pre-determined display layout plan on the digital smart paper device 100. This can be achieved through a program control code embedded in the microcontroller 120 of the digital smart paper device 100. In addition, to achieve this functionality the wireless device may be required to have encoding capabilities to match the digital smart paper device 100. There can also be an image transformation software or application provided to achieve this.
[0026] In an another embodiment of the invention, the digital smart paper device 100 can also turn into a radio-active device when in communication with another wireless device. Hence, when the digital smart paper device 100 comes in contact with a wireless device, it becomes active and then it is possible to read or write to the digital smart paper device 100. This means that data can be written or erased from the digital smart paper device 100 locally or even remotely. This can be achieved by keeping a log of various smart paper devices like device 100 in a remote server and the authenticated devices with whom device 100 can communicate. Therefore, when the digital smart paper device 100 comes in communication with any pre authenticated device, a confirmation message is sent to the remote server, which authenticates the pre-authenticated device and confirms that the message originated from the pre-authenticated device and activates the digital smart paper device 100. Hence, any data can be then written or erased remotely from device 100 when it is activated. Accordingly, the digital smart paper device’s 100 read and write operation can be controlled from the remote server.
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[0027] The microcontroller 120 may also, contain another program control code that helps in control of the pixel array 106. The control can be, in an embodiment of the invention, to control the timing of the display, the style of the display, the alignment of the content being displayed, or, the specifications of the display like size, resolution etc. The display of image can also be formatted according to cress section A*B of the digital smart paper device 100. Here A and B is greater than 2. Also, orderly arrangement of an image may also be achieved according to hardware algorithm that necessitates scanning of pixels in an order such that it includes a start point and an end point wherein, the start point and end point may be in different display layers.
[0028] The microcontroller 120 may, further include a program control code in which the microcontroller 120 is capable of recalling any previous images displayed on the digital smart paper device 100. This is performed in conjunction with the non-volatile memory 118.
[0029] The flexible circuit board with printed electronics 108 further includes a wireless communication chip 122 to enable the digital smart paper device 100 to connect to other devices wirelessly. In an embodiment of the invention, the wireless communication chip 122 may be a Wi-Fi chip, a Bluetooth chip, an IR chip or an NFC chip. Though, the digital smart paper device 100 is configured to act as a standalone device, however, in presence of another wireless device it can act like a quasi-active device. Wireless device could be anyone of a mobile, laptop, tablet computer, personal computer, personal digital assistant, or a digital diary etc. The microcontroller 120 may include a program control code for a communication protocol to communicate with the other wireless devices. Herein the program control code first authenticates the wireless device with which the digital smart
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paper device 100 is trying to communicate and hence the data to be displayed is transmitted and stored in the memory 118 of the digital smart paper device 100 to be displayed. For communication, a negotiation for authentication takes place in between the wireless device and the digital smart paper device 100. Only after the wireless device has been authenticated, the data is transmitted to the digital smart paper device 100 for display.
[0030] Still referring to FIG. 2b, the flexible circuit board with printed electronics 108 further includes a flexible wireless charge receiving chip 124 in order to receive wireless charge. Hence, the digital smart paper device 100 is wirelessly chargeable.
[0031] Now referring to FIG. 3 that displays a cross sectional view 300 of the placement of various layers of the digital smart paper device 100 with monochrome or colored device 100. The digital smart paper device 100 includes an upper transparent encapsulation layer 302a and a lower transparent encapsulation layer 302b to give a two sided display. Beneath both transparent encapsulation layers are present layers of transparent electrodes 304a, 304b, 304c and 304d. In between the lower transparent electrodes 304b and 304d is provided a layer for interface electronics 308a and 308b. In the middle, there is present main plastic substrate layer/middle handle layer 310 that forms the flexible middle plane104. Within the flexible middle plane104 are present via channels 314a, 314b, 314c and 314d in order to provide the electronic circuitry on both sides of the digital smart paper device 100 to make a dual sided display. In an embodiment of the invention, the vias could be either buried or blind vias. Also, in place of vias, there can be other techniques like backside exposure technique to communicate with the electronics on both sides. There is also present a front panel electronics layer 316 for the digital smart paper device 100. The Transparent encapsulation layer includes pigments 312a, 312b. For a monochrome smart
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paper device 100, the pigments 312a, and 312b are monochrome, or if the smart paper 100 is colored, the pigments 312a, 312b are colored.
[0032] Further, Fig. 4 illustrates an exploded view of the display 102 of the digital smart paper device 100. The display 102 includes one or more display layers having electrophoretic medium configured on TFT active matrix platform. As shown in Fig. 4, the display 102 includes two layers L1 and L3 interposing a layer L2, comprising TFT active matrix platform, there between. Each of the layers L1 and L3 consist of two layers – the top layer L1a being a transparent conductive electrode, usually including Indium Tin Oxide (ITO) thin film, and the bottom layer being microencapsulated electrophoretic display medium. The bottom layer L1b is in contact with the TFT based active matrix platform of L2. The two layers L1 and L3 enable display of data on both sides as back to back, providing similar experience as reading a printed paper book.
[0033] Further, the layer L2 includes three sub layers comprising two TFT layers T1 and T2 interposing buffer layer B there between. The bottom layers of layers L1 and L2 are coupled to the TFT layers T1 and T2, respectively. The TFT layers incorporate organic TFT based transistor logic that are wired and printed in a common substrate of plastic material, thereby rendering it flexible, unbreakable and water proof. Furthermore, the middle layer B is the utility layer and carries the interface electronics within it.
[0034] Referring to FIG. 5, illustrating a pixel array 106 attached to the flexible middle plane104. The pixel array 106 contains rows and columns of electrodes and various display elements or pixels 1062. As known in the art, the pixels 1062 or display elements are smallest addressable element in an all points addressable display device. These are the
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smallest controllable element of a display surface. A pixel is a single point in a graphic
image. Graphics monitors display pictures by dividing the display screen into thousands (or
millions) of pixels, arranged in rows and columns. The pixels are so close together that they
appear connected. In an embodiment of the invention, the pixel array can be controlled by
the microcontroller 120 through a program control code embedded within the
microcontroller 120 as mentioned above.
[0035] Referring to FIG. 6 that illustrates internal electronics arrangement 600
within the pixel array 1062. The electronic arrangement 600 includes an electrophoretic
display medium (EPD) 604 disposed in between two electrodes 602a and 602b also
described as pixel electrodes. These pixel electrodes 602a and 602b are in a parallel
connection with a drain capacitor 606. Drain capacitor 606 and the pixel electrodes 602a and
602b arrangement is in a series connection with a drain line 608, which in turn is connected
to a gate line 610. The electronic arrangement 600 also includes various other capacitors like
gate capacitor 612 and source capacitor 614 to drive the electronic arrangement 600. The
each row/array is being controlled using the word line and bit line technique. Each gate line
electrode is connected to the word line and each drain line connected to the bit line
. Exciting each of those word line and bit line will result in displaying content in the
electrophorectic based pixels in an order or sequence with the MCU based driving function
on the integrated circuit.
[0036] Now referring to FIG. 7 that illustrates a flow chart to depict a method 700
to manufacture the digital smart paper device 100. Reference will be made to other Figures
in conjunction to the explanation of steps of the method 700. The method starts at step 702
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wherein the flexible base middle plane 104 is provided. In an embodiment of the invention the flexible middle plane 104 may be formed from a plastic such as polyethyleneterephthalate (PET) or polyethelenemaphthalene (PEN). Moving to step 704 a layer of interface electronics is placed on both sides of the flexible middle plane 104 i.e. layer 308a and 308b described in FIG. 3. In an embodiment of the invention, the interface electronics layer may also be fabricated on the flexible circuit board 108 and then this flexible circuit board 108 is placed on both sides of the flexible middle plane 104. Furthermore, the method 700 includes, at step 706, placing of the pixel array layer 106a, and 106b on each of the interface electronics layer 308a, and 308b. Moving to step 708, the display layers 102a and 102b are mounted over each of the pixel array layers 106a, and 106b and are configured in a manner to display the content in continuity.
[0037] It is to be appreciated that the digital smart paper device 100 described above may be utilized for various applications like secondary display, primary document receiving, wireless handheld document receiver, messaging platform, electronic Hard Post It ,e-reader, document storing, document display, prescription device, identification credentials holding device, and various other applications of the future.
[0038] Although the present invention has been illustrated and described as embodied in various exemplary embodiments, it should be understood that the present invention is not limited to the details shown herein. Since it will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various embodiments modifications presently unforeseen or unanticipated alternatives, modifications, variations,
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or improvements therein may subsequently be made by those skilled in the art, which are also intended to be encompassed by the following claims.
[0039] The principles associated with the various embodiment defined herein may be applied to other embodiments. Therefore, in no way, the examples or the description is intended to be limited to the embodiments shown along with the accompanying drawings but is to be provided broadest scope consistent with the principles and novel and invention features describe/disclosed or suggested herein. Any modifications, equivalent substitutions, improvements etc. within the spirit and principle of the present invention shall all be included in the scope of protection of the present invention.

We Claim:
1. A digital smart paper device, comprising;
a base middle plane wherein the base middle plane is flexible;
a layer of interface electronics disposed on both sides of the base middle plane, wherein the interface electronics are able to communicate with each other;
a pixel array layer disposed above both the layers of interface electronics; and
a display layer disposed on each of the pixel array layer, wherein both the display layers are configured to display a content in continuity.
2. The digital smart paper device of claim 1, wherein the pixel array layer includes pixel pigments.
3. The digital smart paper device of claim 2, wherein the pixel pigments are anyone of a colored or monochrome pixel pigments.
4. The digital smart paper device of claim 1, wherein the base middle plane is made up of flexible substrate.
5. The digital smart paper device of claim 1, wherein the flexible substrate is plastic.
6. The digital smart paper device of claim 1, wherein the interface electronics includes a flexible battery.
7. The digital smart paper device of claim 6, wherein the flexible battery is printed.
8. The digital smart paper device of claim 1, wherein the interface electronics further includes a flexible microcontroller.
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9. The digital smart paper device of claim 1, wherein the interface electronics further includes a flexible wireless connection chip.
10. The digital smart paper device of claim 1, wherein the interface electronics further includes a battery recharging source.
11. The digital smart paper device of claim 10, wherein the battery recharging source includes a solar cell or kinetically chargeable source.
12. The digital smart paper device of claim 1, wherein the interface electronics further includes a flexible memory.
13. The digital smart paper device of claim 12, wherein the flexible memory is a non-volatile memory.
14. The digital smart paper device of claim 1, wherein the digital smart paper device is of any size.
15. The digital smart paper device of claim 1, wherein the digital smart paper device is rollable.
16. The digital smart paper device of claim 1, wherein the digital smart paper device is bendable.
17. The digital smart paper device of claim 1, wherein the digital smart paper can function as an internet of paper device.
18. The digital smart paper device of claim 1, wherein the digital smart paper is a quasi-active device.
19. The digital smart paper device of claim 1, wherein the content displayed is anyone of a document, or an image.
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20. The digital smart paper device of claim 1, wherein the digital smart paper device is wirelessly chargeable.
21. A method of manufacturing a digital smart paper device, the method comprising;
preparing a flexible base middle plane;
placing an interface electronics layer each on both sides of the flexible base middle plane;
placing a pixel array layer on each of the interface electronics layer; and
mounting a display layer on each of the pixel array layer, wherein both the display layers are configured to display a content in continuity.
22. The method of manufacturing a digital smart paper device of claim 21, wherein the method further includes arranging pixel pigments in the pixel array layer.
23. The method of manufacturing a digital smart paper device of claim 21, wherein the method further includes placing the interface electronics on a flexible circuit board on both sides of the base middle plane.