The present invention generally relates to displays and more particularly relates to thin displays that are printed.
Thin displays are becoming popular for use in many applications due to their low weight, high contrast ratio, and their manufacturability through printing. These displays are typically fabricated with electrically conductive tabs to be supplied electric energy from sources such as non-rechargeable or rechargeable battery, rectified RF field generated electricity, solar panels or equivalent devices. Displays are evolving to represent images and text, but also present color changes.
These thin displays (thickness can be as thin at 50 micrometers) can be used in a multitude of new factors that require rethinking the interconnection structure of these displays for both assembly as well as repairs of devices once deployed in the field. These devices vary from game boards to laminated plastic cards to billboards.
Glass-based displays (typically thicker because of the inherent thickness of the glass substrate), the connection to the rest of the device is typically performed through elastomeric zebra strips, heat-seal interconnects, or pin type connector.
For thinner plastic displays, these techniques are neither feasible nor cost effective. Rather, electrically conductive tabs are generally attached to the display exposed electrodes. These tabs are typically flimsy tabs extending outwardly from the display or bent around the exterior of the display package. As a result, the electrically conductive tabs are susceptible to breaking off or tearing and are easily damaged during processing and installation. In addition, because the electrically conductive tabs protrude beyond outline of the display, they create an irregular perimeter around the display that limits the form factors of the products using those displays.
When laminating such a display in a thin device, such as a smart card or smart label, a sink or pocket may be created by the space between the protruding tabs, resulting in surface defects that negatively affect the performance of the device in terms of surface flatness as stated in ISO 7816 series. It might require the introduction of planarization layers, a costly step that can lead to lower manufacturing yield.
Another significant drawback of conventional thin packaged display designs is that the protruding electrically conductive tabs typically require a soldering or welding step in order to make an electrical connection between the tabs and the electrical circuitry of the device into which they are installed. Depending upon the geometry of the device in which the displays are installed, this soldering or welding step may be difficult or impractical. It also restricts the form factor of the final device the display is integrated in by introducing extra area outside the footprint of the display.
Traditional thin displays are also less conducive to replacement in the field. This is a drawback for devices such for a digital billboard or surface of a large system such as car. In such configurations, displays are truly tiles that show fit together to form a larger surface. Tiles should be replaceable readily in the field without requiring a soldering iron or like equipment.
The present invention provides solutions to these problems.
The present invention provides for a display having a front plane, a back plane and a border edge. The display includes a color changing cell located behind the front plane of the device and a first and second electrically conducting attachment layer. The color changing cell includes an active color layer having at least one active color area. The active color layer is associated with a first electrically conducting layer which overlaps at least one active color area. The color changing cell also includes a counter layer associated with a second electrically conducting layer. A first electrically conducting attachment layer extends from the active color area and overlaps the first electrically conducting layer. A second electrically conducting attachment layer extends from the counter layer and overlaps the second electrically conducting layer.
In one embodiment, the display may further include electrically conductive tape as anisotropic electrically conductive tape or an isotropic electrically conductive tape. In another embodiment, the electrically conducting attachment layer is made from anisotropic electrically conductive tape or an isotropic electrically conductive tape.
The color changing cell may be based on a variety of display devices which undergo changes in color the application of a voltage source to at least a pair of electrodes of the display devices. In one embodiment, the color changing cell is an electrochromic cell.
In accordance with the present invention, the device may be operatively coupled with an electronic circuit, wherein the electronic circuit is embedded under the back plane of the display. In one such embodiment, the electronic circuit may include computing capabilities, memory capabilities, communication capabilities, a plurality of address and/or a printed antenna.
The device of the present invention may be used in a variety of devices such as a smart card, a smart label, an electronically readable card, an RFID tag, an electrically powered label, a smart package, a medical device, a sensor, a temperature measurement device, or a wearable medical device.
The present invention also provides for a device including a plurality of self-adhesive displays having color changing cell located behind the front plan of the device and a plurality of electrically conducting attachment layer where the display is coupled to an electronic circuit. The device is operative coupled to at least one controller. In one embodiment, the controller implements a zero configuration networking algorithm. In another embodiment, the controller assigns to each display a color, an icon, a color change, a pixel, and an image, to thereby generate a device image. The self-adhesive devices may be associated with objects such as a vehicle, a billboard, an internal wall, a container, or an external wall.
The accompanying drawings, which are included to provide further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.
Reference will now be made in detail to the preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
The present invention provides for displays having improved constructions, packaging, and associated electronics are provided. The displays are designed to provide at least one of the following characteristics: 1) some of the displays provided herein do not require a soldering or welding step in order to be connected to an external electronic device; 2) some of the displays provided herein include reinforced electrically conductive tabs; 3) some of the displays provided herein have irregular perimeter shape which helps eliminate surface defects when the displays are incorporated into small and/or flat electric devices; 4) some of the displays provided therein have electronics integrated within their footprint; 5) certain displays can constitute the entire side of a device; 6) certain displays can readily assembled into a large displays. The display constructions provided herein are well suited for the design of thin, flat-profile displays, including laminated display structures and large display structures.
The connection of the display to the an additional electronic system is one of the areas of improvement uniquely enabled by the introduction of all print (and at times low temperature manufacturing process, one where the maximum manufacturing temperature is in the range of 80° C. to 120° C.) as described in U.S. patent application Ser. No. 12/______, filed on Mar. 21, 2008 and incorporated herein by reference in its entirety.
An important side benefit of the low manufacturing printable nature of those displays is that electronic components can now be printed on the same substrate as the display itself or under the display resulting in a more self sustaining display and electronic device. The electronic components can provide functionality associated with the display itself (such as regular of voltage or current being applied to it). The electronic components can also be used to provide functionality at the device level.
The present invention provides for an easily laminable display and tile-able displays. The display has a front plane, a back plane and a border edge. The display includes a color changing cell located behind the front plane of the device and a first and second electrically conducting attachment layer. In one embodiment, the front plane of the device includes the front side of a substrate used in the device. In one embodiment, the back plane of the device is behind the final layer used to construct the color changing cell. The color changing cell includes an active color layer having at least one active color area. The active color layer is associated with a first electrically conducting layer which overlaps at least one active color area. The color changing cell also includes a counter layer associated with a second electrically conducting layer. A first electrically conducting attachment layer extends from the active color area and overlaps the first electrically conducting layer. The second electrically conducting attachment layer extends from the counter layer and overlaps the second electrically conducting layer. Electric components may be placed on the back plane of the device.
In one embodiment, the device includes at least two first electrically conductive attachment layers extending from under at least two active color areas and overlapping the first electrically conducting layer. In one such embodiment, an electrically conductive adhesive tape is disposed onto each of the at least two first electrically conductive attachment layers.
The color changing cell may be based on a variety of display devices which undergo changes in color the application of a voltage source to at least a pair of electrodes of the display devices. Representative display devices include electrochromic displays, thermo-chromic displays, electroluminescent displays, electrowetting displays, electrophoretic displays and other reflective and emissive displays. For an electrochromic display, the display print stack includes layers having representative compositions of: a transparent nanostructured semiconducting metal oxide; an electrolyte; an electrochromophore, a reflective metal oxide, an isolator material. One of such layers is common to the component print stack. Representative materials used to make an electrochromic display are described in U.S. Pat. No. 6,301,038, U.S. Pat. No. 6,605,239, U.S. Pat. No. 6,755,993, U.S. Pat. No. 6,870,657, U.S. Pat. No. 6,879,424 and U.S. Pat. No. 7,054,050 each of which is incorporated herein by reference in its entirety. For a thermo-chromic display, one of the layers within the display print stack includes at least one thermochromic material which changes color as the temperature of the material increases beyond a thermal threshold. The display print stack may also include material to form a thermal insulation layer. Representative materials used to make a thermochromic display are described in U.S. Pat. No. 5,557,208 which is incorporated herein by reference in its entirety. For a printed electroluminescent display, one of the layers within the display print stack includes glass encapsulated phosphors or phosphor crystals embedded in a polymer binder. An electrophoretic display print stack includes at least one layer containing an electronic ink. Representative electronic inks are described in U.S. Pat. No. 5,930,026, U.S. Pat. No. 5,754,332, and U.S. Pat. No. 6,850,355 each of which is incorporated herein by reference in its entirety.
In one embodiment, the color changing cell is based on an electrochromic display structure 100 as illustrated in
In one embodiment, the insulation layer 104 is typically a porous structure saturated in electrolyte is preferably electrically insulating, but nothing precludes the inclusion of redox elements in the electrolyte to create a self-erasing cell. The electrolyte, in charge reservoir layer 105, should be as pure as possible, but nothing precludes the inclusions of impurities and/or chemical elements/compound used to perform irreversible transformation of the one or more active color areas 103.
A color changing cell based on an electrochromic display will have a variety of properties depending on the electrochromic material used for the cell. The electro-optical effects can be bistable (where an image is retained on the display until forced to disappear), self-erasing (where an image disappears shortly after the application of charge), or permanent (where an image appears and last forever after the application of a charge). The electro-optic effects of these electrochromic displays may be based on reduction effect (where electrons are being provided to a chromophore structure), oxidation effect (where electrons are being removed from the chromophore structure) or change in pH level (where protons are being generated or removed as in U.S. Pat. Nos. 6,879,424, 7,054,050). The electrochromic material can be deposited on films or part of the electrolyte structure. The electrolyte structure can be a liquid, water based, a gel, a polymer, an olygo-polymer, or a molten salt (e.g. ionic liquid).
In some embodiments, the displays include an electrically conducting attachment layer attached to the bottom of the display 100. In one such embodiment, the attachment layers can be made to cover the entire backplane of the display except for a gap that that separate them. This gap can be created through the printing of the attachment systems or through laser or UV etching. In one embodiment, the gap can be as small as 25 micrometers. In another embodiment, the gap is at least 50 micrometers. The advantage of such a structure is that it provides an electrical ground plate that can be used to shape electrical and magnetic field when the device incorporating the display is a wireless device of. It can also be used as a shield system to reduced unwarranted electrical or thermal effects.
This attachment system has the advantage to fit with the display parameter, thus reducing the overhead need to integrate the display in a device. It can also be shaped in case the display has an irregular shape such as puzzle piece.
An advantage of this framing is to provide enhancement structural integrity to the display. Another advantage is that is allows electrical contact between adjacent displays. This simplifies greatly the connectivity to power sources and remove the need for a complicated backplane to support these multiple displays.
In one embodiment, the electrically conductive attachment layers are made of electrically conductive adhesive tape. In one embodiment, the electrically conductive adhesive tape may be isotropically conductive tape. In another embodiment, the electrically conductive adhesive tape may be a strip of z-axis anisotropically electrically conductive adhesive tape.
In another embodiment, the electrically conductive attachment layer is coated with a conductive film. In one embodiment, the conductive film is made of carbon. In another embodiment, the conductive film is made of a conductive polymer.
In another embodiment, strips of electrically conductive adhesive tape are disposed onto the first electrically conductive attachment layer and the second electrically conductive attachment layer. This allows the electrically conductive attachment layers to be electrically connected to an external electronic device without soldering or welding the attachment layers in place. Placement of conductive adhesive tape over the relevant parts of exposed surface of an electrically conductive attachment layer will provide electrical connections between the attachment layers and electrical contacts in a device into which the display is to be installed.
In one embodiment, the electrically conductive adhesive tape may be an isotropically conductive tape. In another embodiment, a strip of an anisotropically electrically conductive adhesive tape (i.e., tape that conducts only in the direction perpendicular to the plane of the tape) is placed over and bridging both electrically conductive attachment layers. In this embodiment, the strip of tape partially or entirely covers the space defined between the two tabs and creates a more regular perimeter for the display.
The electrically conductive adhesive tapes used to make the electrical contacts are typically made from adhesives having electrically conductive particles dispersed therein. These include, but are not limited to, pressure sensitive adhesives, heat sensitive adhesives, and heat curable adhesives. Specific types of adhesives that may be used to construct the electrically conductive adhesive tapes include, but are not limited to, acrylic adhesives, silicone adhesives, epoxy adhesives, and polyether amide adhesives. Electrically conductive fibers and particles may be dispersed in the adhesives include, but are not limited to, nickel particles, gold coated polymer particles, and silver coated glass particles. The binder adhesive is desirably a heat-activated adhesive that activates at temperatures of at least about 120 degree Celsius.
Suitable electrically conductive adhesive tapes are commercially available from 3M. Specific examples of isotropically electrically conductive tapes available from 3M include Electrically Conductive Tape 9713, Adhesive Film 9708. Specific examples of anisotropically electrically conductive tapes available from 3M include Electrically Conductive Tape 9703, Z-Axis Adhesive Film 7303.
Technical literature further describing tapes, anisotropic films, and anisotropic conductive tapes include, for example: U.S. Pat. No. 6,260,262; U.S. Pat. No. 5,422,200; U.S. Pat. No. 6,517,618; U.S. Pat. No. 6,293,470; U.S. Patent Appl. Publication No. 2003/0002132; U.S. Patent Appl. Publication No 2003/0209792; and U.S. Patent Appl. Publication No 2001/0015483.
In another embodiment, the frame created by the electrically conductive attachment layers can be used to provide room for an electronic subsystem integrated on the outside of display but within its foot print. This approach has the advantage to support a tight integration with electronics that are thin. This circuitry can be deposed on the back of the display or added to substrate itself attached to the back of the display. One such embodiment is illustrated in
The display may operatively coupled with electronic circuitry. In one embodiment, the electronic circuitry is embedded under the back plane of the display. In another embodiment, the electronic circuitry is external to the display device. In another embodiment, the electronic circuitry is disposed on the back plane of the display.
The electronic circuitry may perform a variety of functions. In one embodiment, the electronic circuit includes computing capabilities. In another embodiment, the electronic circuit includes memory capabilities. In still another embodiment, the electronic circuit includes communication capabilities. In still yet another embodiment, the electronic circuit includes a plurality of addresses. In another embodiment, the electronic circuit includes a printed antenna.
The displays may be used in a broad range of devices. However they are particularly well suited for use inside smart cards, smart labels, RFID tags, medical devices, and other small devices that require high temperature/high pressure lamination processing.
A basic and novel feature of some of the embodiments is that displays can be made without the need to solder or weld electrically conductive tabs by using the electrically conductive adhesive tape. Another basic and novel feature is the use of conductive adhesives, including curable conductive adhesives, to provide electrical connections between electrically conductive tabs and external devices. These features represent important manufacturing improvements.
As discussed above, the display includes electrically conductive attachment layers 108, 109 which may be made of electrically conductive adhesive tape or have electrically conductive adhesive tape placed on a separate electrically conductive attachment layer. The inclusion of the electrically conductive adhesive tape, by either embodiment, creates a self-adhesive display which can be attached to a variety of structures.
The present invention also provides for a laminated structure as illustrated in
The present displays are well suited for use inside smart cards, smart labels, RFID tags, medical devices, and other small devices that require lamination processing (e.g., high temperature/high pressure lamination or low temperature/reduced pressure lamination). In some instances, the displays may be designed to withstand temperatures of 80 to 140 degree Celsius and pressures of 200 to 300 PSI for dwell times of 5 to 20 minutes.
The term smart card may be used to refer to any of a variety of electronically readable cards. These cards, which are generally small flexible cards, e.g., plastic cards about the size of a credit card, typically include a microprocessor, a memory and an interface for transmitting and receiving data from an external source. A typical smart card includes a processor coupled to an electrically erasable programmable read-only memory (EEPROM), and/or read only memory (ROM) and/or random access memory (RAM). These components are fabricated onto a single integrated substrate to further include a microprocessor for executing instructions and storing data in the memory. Such smart cards further include an input/output (I/O) signal interface for exchanging I/O signals between the smart card and an external device, such as a card reader. Communication to the reader can be through contacts or contactless (RF coupling).
Smart labels (at times also known as radiofrequency identification or RFID tags) refer to electrically powered labels that may be used to track a vast range of products. Smart labels typically include microprocessor, an antenna and an encapsulating material and/or support. The label may be powered by electric fields generated by a reader and communicate with the reader through its antenna. The label may be powered through an internal battery as well.
A device can be at the same time a smart card and a smart label.
These displays are well suited to go on devices with odds shape such as toys (say the windshield of the car), puzzles (with irregular shapes) and board games.
Self adhesive displays have key advantage when used to create a display made from multiple displays. The multiple self-adhesive displays may be integrated with electronics through a variety of means. In one embodiment, the self adhesive display is attached to a control structure 120, attachment through ink traces 119 to external electronics. In another embodiment, the self adhesive display is attached to embedded electronics. In still another embodiment, the self adhesive display is attached to electronic external to the display.
The introduction of multiple displays composing a bigger display or system requires not only provision of power, power cycling, but also provision of addressing the display in what is now a single display-tile (or tile) in a larger system. An important aspect of building such a display is to create a system that allows a big image to be divided along a series of images for what is an essentially a connection of display. To accomplish this, one need to manage the topology of the display as necessary. Thinking of a large display as a map, this management is assignment of a specific color, pattern, or image to the tile at a given latitude or longitude. Another important aspect of this management is to be able to address (for the purpose of routing information) the tile at that location.
In one embodiment, multiple sub-displays may be placed on a grid supported by a physical backplane to form a larger display. This can be used to create a digital billboard or cover a large area such as building, car, vehicle, or ship.
This display can now readily be build because each sub-display has a sub-display address associated with it. That display address can be stored in EEPROM, Flash, or RAM memory 129 on the sub-displays 126. This sub-display address can be an IP address or an equivalent system. The display is managed by sub-display controller 127 which hosts a database 128 of sub-display addresses. This database can be a simple flat file, link list, doubled-link list. Using a self-discovery standard such as UPnP, this controller can assign addresses to specific physical location on the display with the need for human intervention. Information on UPnP can be found on http://www.upnp.org/
This sub-display controller 127 interfaces with a display controller 130 that has responsibility to set the image/icon/pixel/color change for each sub-display location based on the image/color pattern needed across the entire display. That display can use a database 131 to facilitate that operation. In one embodiment, display controller 130 is not a physical entity but a logical entity. In one embodiment, sub-display controller 127 and display controller 130 can be a single entity. In another embodiment, sub-display controller 127 and display controller 130 can be integrated with a third entity.
The sub-display controllers 125 and display controllers 127 can be hosted in a single device and indeed this device can be one of the sub-displays. UPnP indeed contemplates architectures where multiple devices are controlled by multiple controllers. The complexity of such algorithms makes it readily implemented inside a microcontroller. This type of architecture would have extremely good serviceability.
The present disclosure may be embodied in other specific forms without departing from the spirit or essential attributes of the disclosure. Accordingly, reference should be made to the appended claims, rather than the foregoing specification, as indicating the scope of the disclosure. Although the foregoing description is directed to the preferred embodiments of the disclosure, it is noted that other variations and modification will be apparent to those skilled in the art, and may be made without departing from the spirit or scope of the disclosure.
This application claims the benefit of U.S. Provisional Application No. 60/896,101, filed Mar. 21, 2007, entitled “Expanded and Accelerated Commercial Road Map Items” which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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60896101 | Mar 2007 | US |