WO2018204582A1 - Détermination électrique de messages sur un dispositif d'affichage électrophorétique - Google Patents

Détermination électrique de messages sur un dispositif d'affichage électrophorétique Download PDF

Info

Publication number
WO2018204582A1
WO2018204582A1 PCT/US2018/030797 US2018030797W WO2018204582A1 WO 2018204582 A1 WO2018204582 A1 WO 2018204582A1 US 2018030797 W US2018030797 W US 2018030797W WO 2018204582 A1 WO2018204582 A1 WO 2018204582A1
Authority
WO
WIPO (PCT)
Prior art keywords
active matrix
display
matrix display
pixels
signal
Prior art date
Application number
PCT/US2018/030797
Other languages
English (en)
Inventor
John Rilum
Paul Atkinson
Original Assignee
Chromera, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Chromera, Inc. filed Critical Chromera, Inc.
Priority to EP18794561.3A priority Critical patent/EP3619701A1/fr
Publication of WO2018204582A1 publication Critical patent/WO2018204582A1/fr

Links

Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3433—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices
    • G09G3/344—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices based on particles moving in a fluid or in a gas, e.g. electrophoretic devices
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2340/00—Aspects of display data processing
    • G09G2340/14—Solving problems related to the presentation of information to be displayed
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2358/00—Arrangements for display data security
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2360/00—Aspects of the architecture of display systems
    • G09G2360/16—Calculation or use of calculated indices related to luminance levels in display data
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2370/00—Aspects of data communication
    • G09G2370/06—Consumer Electronics Control, i.e. control of another device by a display or vice versa
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2380/00—Specific applications
    • G09G2380/04—Electronic labels
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/03—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes specially adapted for displays having non-planar surfaces, e.g. curved displays
    • G09G3/035—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes specially adapted for displays having non-planar surfaces, e.g. curved displays for flexible display surfaces

Definitions

  • the present invention relates to an intelligent label that is particularly constructed to be associated with a good, and to enable trusted and verifiable reporting of the condition of that good.
  • the label's electronics is used from time to time to interrogate its display and verify that the desired message is actually perceptible, and in some cases may be useful for generating a historical record of what was displayed or perceptible as the product moved through distribution and use.
  • Intelligent labels, packaging, tags, windshield stickers, stand-alone displays and other devices benefit from electro-optic devices that display messages that alert, update and inform the persons or machines proximate to them, as fully set forth in co-pending patent application number 14/479,055, filed September 5, 2014, and entitled “An Intelligent Label device and Method,” which is incorporated herein in its entirety.
  • This earlier application describes an intelligent label that can be attached to any good, and then is used to provide a visual indicator to a human or machine on some condition or event in that distribution path. Of particular interest therefore are bistable and permanently irreversible electro-optic displays and intelligent labels that comprise them.
  • a visual indicator may be set such that a human or a machine will understand that the good is no longer of acceptable commercial quality.
  • Messages for the intelligent label are visually perceptible forms of data, information, content, text, patterns, images, shapes, symbols, codes, and colors, for example. It is important to note that these are visual systems and the messages may change one or more times over the life of the intelligent label. Further the power source that drives them may be limited or intermittent or susceptible to accidental or intentional disruption. Other components of the intelligent label may also fail or be subject to tampering.
  • the message that is intended by the local electronics to be displayed on the intelligent label may not actually be what the user or machine perceives. Accordingly, in some applications the utility and value of intelligent labels may depend on the confidence with which the messages can be relied upon to make decisions and take actions, and further, that the actual messages perceptible at the time those decisions were made or could or should have been made, and actions were taken or could or should have been taken can be reliably and securely verified.
  • doctors and other healthcare professionals need to know that they will only be held accountable for decisions made and actions taken based on the information reliably available at the time. Hospitals need to know too. As do patients and insurers and everyone else with a stake in the outcome. And they also need to know that if something goes wrong, the system cannot be tampered with and of its information is trustworthy.
  • a bag of blood has reached its maximum allowed time out of refrigeration, and the electronic circuitry on its attached intelligent label has instructed a message to be displayed on the bag's irreversible display that indicates that the bag of blood can no longer be used safely.
  • the electronic messages stored within the intelligent label's processor and memory would indicate that at the correct time the visual indicator transitioned to show that the condition of the blood had changed was no longer safe.
  • an electronic or logical failure may have occurred and the visual alert message was never perceptible to the nurse or doctor.
  • an experimental drug may have its expiration date shortened due to a better understanding of the drug's deterioration over time.
  • an intelligent label may be updated remotely to remove the original expiration date, and replace the date with a new, shorter expiration date.
  • a patient may wrongly continue to use the drug after the new expiration date, and may later claim that the new expiration date was never displayed. Accordingly, it would be important to know what, if any, change had been made on the label at the time the expiration date should have been changed. Having such a historical understanding of what was actually displayed could be critical to patient care and assigning liability. More particularly, in some cases what was actually displayed may not have communicated the intended message to the patient or care giver.
  • bistable (or multi-stable state) displays such electrophoretic and certain cholesteric or nematic LCDs are to varying degrees stable without the continuous application of power. By design, they are however reversible and the displayed messages are therefore subject to accidental or intentional erasure or alteration. The displayed information therefore cannot be verified reliably visually.
  • visual refers to messages, images and the like that are perceptible by both humans and machine. Certain messages however may be perceptible by machine but not perceptible by humans. For example, they may reflect light at wavelengths outside the human perceptible range (of approximately 390 to 770 nanometers).
  • This characteristic may be exploited in a number of ways, for example to create watermarks and other messages in response to events that are machine perceptible (readable) but not perceptible by humans.
  • the verification systems and means described herein may be utilized with such non-visual, but machine perceptible messages.
  • bistable electrophoretic displays the application of an electrical field switches the position of charged ink particles creating two visible “states" corresponding to, for example, a white and black state as seen by the viewer.
  • the ink particles are typically compartmentalized by use of microcapsules or microcups.
  • Each microcapsule may contain a single or several types of ink particles, e.g. each corresponding to a specific color or optical characteristic, which may have varying degrees of mobility in the suspension fluid as a function of the applied electric switching field.
  • the suspension fluid may further have a different optical characteristic to that of the ink particles, such as, clear, colored, absorbing, etc.
  • the probing write signal is of the same polarity as the original write signal applied to set the display state, there will be no or only a small transient current present as all or most if the ink particles are already at or near one side of the display defining the presumed state.
  • This scheme assumes that not only the state was presumed to be the correct one, but also that the display pixel/segment is functioning correctly. However, if the latter is not the case, for instance due to some irreversible damage present (for example, a discontinuity in of the two corresponding pixel electrodes, or an undesirable chemical degradation within the microcapsule), there could also be no, or only a small (residual), transient current irrespective of the state of the display pixel/segment.
  • the opposite polarity of the probing write signal could deliberately be applied. However, this method would thus change the very display state that is to be verified electrically.
  • An intended message is written to a display, which may be bistable. Pixels that comprise portions of the message are measured and evaluated to determine if the message actually displayed on the display was perceptible by a human or a machine. In some cases, information regarding the message actually displayed on the display may be stored for later use, irrespective of whether or not the display provided a perceptible message. Responsive to determining that a message is perceivable or not perceivable, alarms may be set, one or more third parties notified, or additional display features may be set.
  • the perceptibility of a message written to an intelligent label can be verified. More specifically, electronic circuitry within the intelligent label writes an intended message to a bistable display. Electrical characteristics of the pixels on the bistable display are measured, and a contrast and color profile may be generated. This profile represents the actual message that would have been perceivable by a human or a machine. This actual message can then be compared to the intended message, and a level of confidence that the proper message was presented can be generated. In this way, it can be verified that the proper message would have been perceivable by a user or human at a particular time, for example, when a severe
  • a historical record may be generated and maintained regarding the visual state of the bistable indicator at various times in the lifecycle for the product during use and distribution.
  • the verification process and label disclosed herein allows the visual information on the label to be confirmed and verified that a proper message was displayed and perceptible at a particular point in time. And further, independent of the intended message, the verification processes and labels allow for determination of the actual information displayed, its meaning and its perceptibility. In this way, liability can be more accurately assessed, and the trustworthiness of the entire distribution and use cycle is dramatically improved.
  • a system and method for electrically determining visible or perceptible messages on electronic displays is disclosed herein whereby an electrical signal is accessed within the display which has one or more characteristics that directly or indirectly correspond to the optical state of the display, or more specifically to the optical state of a display pixel or segment (hereinafter collectively referred to as the "display state” or “state of the display”).
  • bistable or multistable reflective displays in which the display state remains stable over a time period significantly longer than the switching time without the application of power to the display.
  • the inventions described herein can be extended to other types of displays including, but not limited to, transmissive, transreflective or emissive (e.g. back or front lit) configurations that may or may not be bistable or multistable.
  • bistable reflective displays which are based on electrophoretic display layers, in which solid particles and a suspending fluid are held within a plurality of cavities.
  • FIG. 1 is an illustration of the front side of an intelligent label made in accordance with the present invention.
  • FIG. 2 is a block diagram of an intelligent label made in accordance with the present invention.
  • FIG. 3 is a block diagram of an intelligent label made in accordance with the present invention.
  • FIG. 4 is a block diagram of an intelligent label made in accordance with the present invention.
  • FIG. 5 is a block diagram of an intelligent label made in accordance with the present invention.
  • FIG. 6 is a flowchart of a process for verifying the perceptive ability of a message in accordance with the present invention.
  • FIG. 7 is a flowchart of a process for verifying the perceptive ability of a message in accordance with the present invention.
  • FIG. 7A is a flowchart of a process for verifying the perceptive ability of a message in accordance with the present invention.
  • FIG. 8 is diagram of segment colors in accordance with the present invention.
  • FIG. 9 is a diagram of a seven-segment display in accordance with the present invention.
  • FIG. 10 is a symbol table in accordance with the present invention.
  • FIG. 11 is a flow chart of the segment color identification process in accordance with the present invention.
  • FIG. 12 is a flow chart of the symbol identification process in accordance with the present invention.
  • FIG. 13 is a flow chart of the message identification process in accordance with the present invention.
  • FIG. 14 is a flow chart of the message display process in accordance with the present invention.
  • FIG. 15 is a flow chart of the symbol lookup process in accordance with the present invention.
  • FIG. 16 is a flow chart of the symbol mask building process in accordance with the present invention.
  • FIG. 17 is a diagram of color strings, segment strings and message strings in accordance with the present invention.
  • FIG. 18 is a diagram of the main message process in accordance with the present invention.
  • FIG. 19 is a diagram of an electrophoretic display in accordance with the present invention.
  • FIG. 20 is a flow chart for an exemplary display state verification process in accordance with the present invention.
  • FIG. 21 is a diagram of an electrophoretic display in accordance with the present invention.
  • FIG. 22 is a block diagram of a verifiable active matrix display in accordance with the present invention.
  • FIG. 23 is a block diagram of a verifiable matrix display in accordance with the present invention.
  • FIG. 24 is a diagram of an electrophoretic display in accordance with the present invention.
  • FIG. 25 is a diagram of an electrophoretic display in accordance with the present invention.
  • FIG. 26 is a diagram of an electrophoretic display in accordance with the present invention.
  • FIG. 27 is a diagram of an electrophoretic display in accordance with the present invention.
  • the intelligent label may take many forms, such as a traditional style label for attachment to a discrete box or package, it may be integrally formed on a package such as a shipping container or mailer, or it may take the form of documentation that accompanies a shipped product. In other examples, the label may be integrated or applied on prepaid gift cards for example, or can be integrated into the good itself. Generally, the intelligent label is intended to enable a highly trusted, robust, and accurate way for safely and securely confirming or reporting a change in the condition of a good, for example, while a good is transported from a point of origin to a consumer or it is held in stock prior to use.
  • the intelligent label enables analytics and an understanding of the quality and handling of the good over time that is not available with prior systems. Further, the intelligent label provides accurate and timely information to various participants in the handling and use process, including the end user, without the need for sophisticated processing, communication, or interrogation systems.
  • the intelligent label has a simple electro-optical display (indicator) for visually presenting selected important information about the quality and handling of the good.
  • a preferred option is an irreversible bistable indicator that cannot be turned back to its original state electronically, and thus is naturally resistant to tampering or accidental alteration. In some labels one may use both bistable and irreversible indicators corresponding to different indicator functions.
  • the electro-optic indicator can be constructed with electrochromic material or electrophoretic material.
  • Bistable indicators may be used to temporarily present a code or information. Bistability means that the display or the indicator changes from a first optical state to a second optical state by using a powering protocol, and remains in the second optical state without the application of additional power. However, this state (the second optical state) can be reversed to the first optical state by applying a different powering protocol and can also be maintained in that state without subsequent application of the power. The length of stability in a given optical state is dependent on the application requirement and a suitable electro-optical display/indicating system meeting that requirement can selected.
  • optical state stability without the application of power, on the order of a few minutes may be acceptable, while in other cases this may extend to several days, months or years.
  • Certain non-emissive electro-optical systems such as electrophoretic, liquid crystal and electrochromic systems can be tailored for various bistability requirements.
  • Another desirable property of these indicators is their environmental durability (time, temperature, humidity (moisture), pressure and radiation (e.g., UV) in both activated and non-activated states so that it is obvious from visually observing the indicator its last state of activation (or inactivation). This environmental stability ensures that it would be difficult to mistake the conveyance of its intended optical state and also difficult to tamper with and also results in a permanence of indicated information.
  • an intelligent label 10 is illustrated. It will be appreciated that the intelligent label may take many forms, however the form illustrated is a fairly typical label for attachment to a good destined for shipment using carriers or delivery companies. In other examples, the label may be integrated into mailers or other shipping containers, may be part of shipping documentation, or may be integrated with the packaging, product or good itself as in the case of a gift card. Referring again to FIG. 1, label 10 is intended for attachment to a good using an adhesive backing. As with a traditional paper label, intelligent label 10 has a print area 11 that may be used for identifying the intended receiver for the good.
  • the print area may contain many other kinds of information, such as additional information regarding the attached good, invoice numbers, purchase order numbers, and additional information to assist the shipper. It will be appreciated that the print information may be placed in many different areas in human-readable or machine-readable form.
  • the print area may include barcode or other man or machine readable 12 to facilitate a more automated way to track process through the shipping chain.
  • the intelligent label 10 also has embedded electronics that enable wireless communication to and from the intelligent label 10 electronics, not visible from the front of label 10, including a power source such as a battery, a processor, memory, and wireless communication, typically in the form of an RFID
  • the intelligent label may also have an optional power harvester to charge the onboard power source such as a capacitor or a battery.
  • the power harvester may produce electric energy from light (e.g., solar cell), RF energy, or due to motion and vibration that the label is subjected to.
  • Intelligent label 10 typically has an actuator, not illustrated from the front, that activates the electronics in the label just prior to the label being attached to the good.
  • the label may have adhesive backing, that when removed, enables the capture of the particular date and time when the label is being attached to the good.
  • the processor would operate in a very low power state to maintain its timer, and then when the adhesive is removed from the back of the label, a higher power mode would be enabled that allowed capture and storage of the current time and day. In this way, the label itself can accurately capture when it is attached to a good in-service.
  • the good may then be placed into the shipping chain, where at each transfer information may be captured from the label using the barcode 12 or from the electronic RFID communications, and additional information may be stored in the RFID areas as well, provided such RFID equipment is available at shipping locations.
  • Actuation, or initiation of the electronics also may be via a variety of means including a remote signal (e.g. RF, optical or electrical) a mechanical, electro-mechanical or electrical switch.
  • Intelligent label 10 also has an electro-optic display area 13 for providing immediate visual information regarding the quality of the product without the need for interrogating the RFID communication system.
  • the processor in the intelligent label 10 contains rules as to how long the shipping process should take.
  • the label 10 could be applied to a box of flowers. The shipper-grower may require that the flowers be delivered within a two-day time span. As soon as the label is applied to the flowers, the timer starts and begins counting the elapsed time that the flowers have been in the shipping process. Initially, the intelligent product label may indicate the flowers as being fresh, but if the shipping time goes behind the limits set in the rules, the processor may cause the electro-optic device to indicate not to accept the flowers.
  • the receiver would be put on visual notification not to accept the flowers.
  • This point could be at the end consumer point, or could be at any other point in the shipping chain.
  • the intelligent label could be set up to inform the end-user to call customer service. Upon calling customer service, the customer may be offered a discount or other incentive to accept the flowers, acknowledging that they are nearing the end of their freshness state.
  • the electrochromic display may have an informational block 15 for providing additional specific information.
  • the information in informational block 15 may provide coded information dependent upon specific attributes of the shipping process, e.g. elapsed time, monitored conditions etc.
  • the informational block 15 would be activated in order to give more specific information as to the broad information given in area 13.
  • the intelligent label 10 shows that the product associated with this label should not be accepted. If, for example, a consumer removes a package from their mailbox with the "do not accept" highlighted, the consumer typically will not have the equipment necessary to interrogate the label through its RFID communication channels.
  • the label also provided an electrochromic indication that provided the additional information as shown in information block 15. Accordingly, when the consumer calls customer support for the provider of the good, the consumer can visually read the code included in block 15 to the customer service representative, and that particular code can be associated with a specific time or event causing the good to go bad. In this way, customer service obtains significant information that is accurate and trustworthy as to where in the shipping chain the product was mishandled. By providing such information, the chances for fraud are decreased, and the opportunity for improved customer service is enabled.
  • the intelligent label may take many forms, but for convenience, the structure and function of the intelligent label will be described with reference to a discrete label having an adhesive backing for attachment to a mailing package or good. It will be understood that other constructions for the intelligent label are consistent with this disclosure, such as a label integrated with a package, integrated onto shipping packaging, or integrated into shipping documentation. It will also be appreciated that other constructions or possible consistent with this disclosure.
  • Intelligent label 25 typically has a front side, which has a print area 27 for communicating information regarding the good itself or the shipping and usage of that good.
  • the information typically is printed onto the label using inkjet or laser printing processes, or may be preprinted.
  • the print information may contain such information as name, address, invoice number, preferred shipper, and other traditional shipping information.
  • Print information may also include information about the use of the goods, or rules regarding how the good should be stored or shipped.
  • the print information may include textual information, as well as barcode or other types of machine readable formats. In this way, the print information can assist a human reading the information, and also may accommodate more automated data collection processes throughout the shipping chain.
  • Intelligent label 25 also has electronics on or embedded within its structure. Electronics includes a processor 28 having an associated clock 29 and storage 30. The processor also manages communication using communication processor 34, which typically is an RFID radio. It will be appreciated that the various electronic components may be implemented using a single integrated circuit device, or may require multiple devices.
  • the electronics for intelligent label 25 require a power source 32 for operation, communication, and transitioning the electro-optic message indicator 33.
  • This power may be supplied, for example, by a traditional primary or a secondary cell battery, a set of thin-film layers constructed as a battery, capacitor, or may be an antenna structure constructed to generate power responsive to an RFID field signal.
  • an electro-optic message indicator 33 which in one construction may be an electrochromic or electrophoretic indicator, for providing additional information regarding the condition or quality of the good.
  • the message indicator 33 may be bi-stable or permanent, i.e., irreversible.
  • the electro-optic material may be specifically formulated and activated in a way that it has two color or transparency states, with the electro-optic material remaining in the first state until it is activated to transition to the second state. Once electrically transitioned to the second state by the processor, this process is irreversible, and the message device 33 remains permanently in the second color or the second transparency state.
  • the particular formulation of the electro-optic material is fully set forth in published US patent application number 20110096388, which is incorporated herein in its entirety.
  • message indicator 33 may be a first color while in the first state, and then when transitioned to the second state, visually present a second color.
  • the electro-optic message indicator may change its transparency state. In this way, electro-optic message indicator 33 could be placed over printed information that would not be visible while the message indicator is in the first state, but then when transitioned, information below could be viewed through the now transparent message indicator.
  • the message indicator 33 may be more complex and structured in a way that can build textual or numeric information, for example, such as using a segment or dot-based character construction. Further, although the message indicator 33 is described as having only two states, it will be appreciated that some indicators may have more than two stable states.
  • the message indicator upon activation, may transition from a first state to a second state irreversibly, and then upon further activation transition reversibly between the second and a third state, i.e., show bistability between the second and the third states.
  • electro-optic message indicator 33 would be transitioned according to rules set in the processor for the particular good that is being shipped. These rules would be implemented using processor 28, and when a rule is satisfied, the processor 28 would cause an appropriate electronic signal to transition the electro-optical material in the message indicator 33. For example, rules may be set that would cause the message indicator 33 to indicate whether or not the package was shipped and delivered within the allotted time.
  • the electro-optic message indicator 33 may be structured as bistable electrophoretic indicator.
  • Electrophoretic technology is most typically seen as an electronic paper display useful for handheld readers and small electronic displays. Electrophoretic technology is well known, but generally, an electrophoretic display forms images by rearranging charged pigment particles (pixels) with an applied electric field. Upon the application of an electrical signal, the pigments reorient themselves so that either a white side or a colored side is presented to the reader. By changing the electronic signal, the pigment can be oriented to the other visual state.
  • Electronic paper, e-paper and electronic ink are display technologies that mimic the appearance of ink on paper. Unlike conventional backlit flat panel displays that emit light, electronic paper displays reflect light like paper.
  • an electrochromic LCD display that is, a display that is not typically considered to be either bi-stable or permanent. Even with such a display, it would be desirable to determine it, a particular time, the correct intended message was being displayed in a perceptible manner, and if not, to capture the pattern that was actually displayed.
  • pattern is used broadly to include any arrangement of pixels, whether or not the pattern of pixels creates a human-recognizable symbol or character.
  • Bidirectional communication may be provided with intelligent label 25 using the communication processor 34.
  • the communication processor 34 may be an RFID radio, although other radios such as ZigBee, 802.11, or Bluetooth maybe used.
  • the communication processes on communication block 34 may be controlled by processor 28, with processor 28 managing what information is sent and received through the radio. Once information is received, it may be stored in storage 30, or rules may be applied to determine if action needs to be taken, such as setting the electro-optic message indicator 33.
  • Intelligent label 25 also has an actuator 31 for determining when the label is being attached to a good, for example. In this way, the actuator provides an accurate indicator of when the good is entering the shipping chain.
  • the actuator in some cases may be provided as a physical mechanical device, and in other cases may be optical, electrical, electro-optical, RF, or chemical. It will be appreciated that the electronics can be activated at other trusted and confirmable times depending on the specific application.
  • Actuator 31 can take many forms, depending upon the physical structure of the intelligent label 25. In one example, the actuator 31 is constructed along with the backing of the label, such as when the backing is removed to expose adhesive, the processor is provided with a signal that the label is about to be attached to the good.
  • the processor can then store the accurate information regarding how the product entered the shipping chain, which can provide useful and accurate comparison information throughout the shipping process.
  • the actuator can be implemented in many alternative ways.
  • the actuator may be set such that the removal of the label backing breaks an electronic circuit that can be detected by the processor.
  • the removing of the backing material and placement of the label on the good may close a circuit, thereby giving a signal to the processor that the label has been attached to the good.
  • the actuator may be pressure activated through the application process, or provide an electronic signal that is generated by some physical action, such as by pulling a tab. It will be appreciated that actuator 31 maybe implement it in a wide variety of ways.
  • Intelligent label 50 is similar to intelligent label 25 described with reference to FIG. 2, so only the differences will be described.
  • intelligent label 50 includes a print area, processor, clock, storage, actuator, power, communication, and a first indicator as set out with reference to intelligent label 25.
  • intelligent label 50 has a sensor 55 that is positioned on, in, or below the intelligent label 50 for sensing something about the environment that the good was subjected to during the shipping process.
  • sensor 55 could be a temperature sensor, a humidity sensor, and altitude sensor, a pressure sensor, an optical sensor, a vibration sensor (including a shock sensor), a humidity sensor, biological or a chemical sensor (including a gas sensor, a pH sensor), a magnetic sensor, and a smoke sensor, etc. It will be appreciated that a wide variety of sensors could be used depending upon the particular good being sold. It will also be appreciated that although only one sensor is shown on intelligent label 50, multiple sensors may be used. For example, a sensitive electronic device may be sensitive to vibration so a vibration sensor would be used, and may have parts that cannot be exposed to temperature extremes, so a temperature sensor would also be provided. However, for convenience intelligent label 50 will be described with reference to a single sensor 55.
  • the processor within intelligent label 50 will have a set of associated rules for the expected environmental conditions that the sensor 55 should be exposed to these rules can be set to simplistically monitor the sensor data, or may contain more sophisticated algorithms as to allowable conditions. For example, a good may remain in a quality state if exposed to a temperature for a short period of time, but would be considered out of specification if the temperature remained for more than a set period of time. It will be appreciated that a wide variety of rules may be set for sensor 55.
  • an electro-optical indicator may be provided for visually indicating the letter, character, or code that provides more information regarding when or why the good was deemed to be unacceptable.
  • the electro-optical indicator provides a human readable visual indicator, a person, such as the end consumer, would not need to wirelessly interact with the intelligent label 50 to obtain meaningful information regarding the state transition.
  • a customer service representative interacting with the consumer would be able to not only verify that the consumer's product has been indicated to be a bad quality, it may be able to determine additional specific information that could improve the shipping process, and provide valuable information in satisfying the customer's needs.
  • FIG. 4 another example of an intelligent label 60 is illustrated. Intelligent label 60 is similar to intelligent label 50 described with reference to FIG. 3, so only the differences will be described.
  • the state detector 62 may be connected to one or more of the electro-optic message indicators. In this way, when a particular rule is set to change one or more electro-optic message indicators, the processor will provide the required power signal to the electro-optic message indicator for it to change to its second state.
  • the processor can then cause state detector 62 to confirm that the electro-optic material has changed states. This can be done, for example, using electrical measurements across the electro-optic indicator, or using optical sensors for physically detecting color, transparency, or opaqueness of the electrical material. In this way, the processor would not only track when it intended to set the electro-optic material into its second state, but would provide further verification information that the state was actually changed.
  • the reliability of the state detection and confirmation may be further improved using knowledge of environmental conditions such as temperature, altitude, number of indicators, and their size, so that electrical parameters of the indicators are accurately predicted and tested both before and after activation.
  • FIG. 5 another example of the intelligent label 70 is illustrated.
  • Intelligent label 70 is similar to intelligent labels 10, 25, 50 and 60 discussed with reference to FIGs. 1-4, so only the differences will be described. Intelligent label 70 does not have a wireless communication capability, so is simpler and less expensive to manufacture, but still enables advantageous and trusted commercial transactions. Accordingly, label 70 communicates through a connector 73 to external or remote devices. Further, label 70 is illustrated having an electrophoretic indicator 71. It will be understood that the electrophoretic indicator 71 can be used with any of the electro-optic message indicators illustrated in FIGs. 1-4.
  • Pixels will be understood to be single addressable visual elements of the display.
  • a pixel may be a 'dot' and in others it maybe a shape such as a 'segment' used in the formation of a 'seven-segment' alphanumeric display.
  • Pixels may also be a variety of shapes, symbols or images that are determined by the surface areas of the electrodes used to signal them.
  • a shape of course may be comprised of multiple pixels.
  • the density, variety and resolution of the displayed messages is not typical of that required for consumer electronics. As such the messages may be generated using comparatively large pixels in shapes optimized for messages appropriate for the application instead of arrays of much larger numbers of significantly smaller pixels.
  • a message consists of the visual 'state' of one or more pixels.
  • a pixel typically has at least two intended states, on each of two high contrast colors (e.g. black and white) and depending on the display, a third (or more) state which is not one of the high contrast colors (e.g. gray or semi-transparent), but sits between the two high contrast colors.
  • the perceptibility of a message or visual information further typically depends on the actual visual state of the message pixels and that of the pixels adjacent or proximate to them.
  • the visual state of a pixel corresponds to an electrically measurable characteristic of the pixel (e.g. voltage, resistance, capacitance, etc.).
  • a pixel thus has a visual state and a corresponding electrical state.
  • a pixel also may be considered to have a single 'state' that has both a visual and a corresponding electrical characteristic.
  • the location or 'address' of each pixel relates to the electrodes used to set its state.
  • a method 75 for verifying the perceptibility of a display is illustrated.
  • the display may be bistable, permanent, or irreversible.
  • the display may be part of an intelligent label, and in a particular construction may be employing an electrophoretic technology.
  • an intended message is typically generated by a computer processor or other electronic circuit, and is stored in a display memory as shown in block 76. It will be understood that such a message may be generated and stored in a wide variety of ways.
  • this message may be an expiration date, an indication of quality, or an alarm indicating that a particular environmental condition has been exceeded. It will be understood that the type and content of the message can vary greatly within the confines of the described invention.
  • Block 76 shows that the processor or driver circuitry attempts to write the intended message to the electro-optical display. In some cases, this intended message may be stored for later use in comparing to what was actually perceptibly displayed. It will also be understood that the intended message may be interrogated in various areas of the electronics, such as by evaluating contents of memory locations or evaluating driver circuitry. It will also be understood that method 75 may be used multiple times during the life of an intelligent label, since the intelligent label may have multiple messages that may be definable at various times in the distribution cycle. Method 75 may also be used to determine or confirm the continued perceptibility of the same message. Generally, the message comprises a set of pixels that when viewed together present the intended message.
  • these pixels may be white, black, gray, or set to another color.
  • the pixels on the display will be activated using an electrode or electrode set to provide an electric stimulation or signal to each individual pixel. It will be understood that the process for activating pixels with electrodes is well understood.
  • block 78 shows that the state of the pixels may be electronically measured to determine their visual state and the perceptibility of any message or information. That is, the individual pixels may be interrogated to determine if they are black, white, a particular color, or some state in between. Often, the interrogation of the pixels may be done using the same electrodes used to set the pixel, however in other cases other separate detection electrodes may be used. Also, it may not be necessary to evaluate or measure all of the message pixels.
  • the pixels there may only be a subset of the pixels that are required to perceptibly present the intended message.
  • the simplest process is to use the same electrode used to set each pixel, measure the electrical characteristics of every pixel of the intended message, and store the measured electrical characteristics. It also may be advantageous to measure the electrical characteristics of the pixels adjacent to the message pixels or of reference pixels.
  • Each of the pixels can now be evaluated to determine if they are of the intended color and contrast. That is, it can be determined if the intended black pixel is actually black, or if it failed to transition at all, or if it is some level of gray in between. In this way, it can be understood if each pixel is properly set, and if not properly set, how close to the correct state it is.
  • the intended pixel states corresponding to the intended message can be compared to the actual pixel states of the display.
  • the message visually perceptible to a user or machine is the intended message. For example, if all the pixels states are as intended, then the perceptible message is the intended message. If a few pixels are not fully set to their intended state, it may be determined that although not perfect, the intended message is still perceptible. In other cases, the differences between the intended states and the actual states may be so significant that it is determined that the message being displayed would not be perceptible by a user or machine. In making this determination, it may be useful to determine a subset of pixels that are actually necessary for generating a perceptible message.
  • a few pixels forming the base of a symbol may not have been properly set to a dark contrast, but having those few pixels properly operate is not necessary for a user to perceive and understand an intended message. That is, whether or not those pixels are black, white, or gray, their particular state creates little or no ambiguity in the perceptibility and understanding of the message.
  • the perceptible information can be stored for later use, may be transmitted to a third-party, may set an alarm, or maybe used to set another new local message. For example, if method 75 determines that a new expiration date is not actually perceptible, the intelligent label may locally cause a second display to present a large red dot showing that there is a severe problem with quality. In a similar way, the label may cause an alarm or message to be sent to a third party, and an indication of the perceptibility of the expiration date as well as that of the red dot, may be stored for later use in verifying what message or information was actually available to user at a specific time.
  • this verification process can be used multiple times to determine what was actually displayed at various times throughout the distribution and use cycle of the product.
  • block 82 it can be determined if the proper message or messages have been perceptibly displayed for use by a human or machine throughout the product distribution and use cycle.
  • the intelligent label has an indicator for informing a viewer that the message has an ambiguity. In this way, the user can take extra care in evaluating the message.
  • a bistable display uses a seven-segment display technology to present an alphanumeric character to a user or machine.
  • the intended message for example the number "7" is stored in memory.
  • Three pixels (segments) out of the seven that characterize an alphanumeric character are 'addressed' by the appropriate electrodes (the top segment and the two vertical segments on the right). Signals are sent to color the three pixels with a first color (e.g. black). Independent of their last-known state the signals are preferably sent to each of the four other pixels comprising the seven-segment character to color them with a second color (e.g. white).
  • a first color e.g. black
  • the signals are preferably sent to each of the four other pixels comprising the seven-segment character to color them with a second color (e.g. white).
  • signals may be sent only to pixels required to change state as determined by their last-known state or last-known-good state. If the state of the pixels proximate/adjacent (surrounding or interstitial to) to the seven pixels comprising the character can be electrically changed (e.g. the pixels are addressable) these pixels may also be sent signals to maximize the contrast between them and the message pixels and thus the perceptibility of the displayed information.
  • the pixel set in this example is preferably the seven pixels that make up the seven-segment display and the surrounding pixels.
  • only the three segments that needed to be transitioned might be measured. However, greater confidence would be established if all seven segments were measured. But, in some power and time critical situations it may be advantageous to measure fewer than all the pixels.
  • Method 85 first sets a minimum contrast between the pixels states needed for perception of a message as shown in block 86. This minimum contrast may be set according to the particular operating
  • the electronics in the intelligent label or the electronics associated with the bistable display write a message to the display. Thereafter, and preferably using the same electrodes that were used to write the message, electrical measurements are taken of the pixels to determine the state of those pixels. In this way, the "on" pixels may be measured to determine how dark or colored they are, and the "off pixels can be measured to determine how light or non-colored they are. Accordingly, in block 89 the contrast levels may be compared between the on and off pixels.
  • method 86 determines if the message is sufficiently perceptible for the particular application and particular environment. Again, in this step whether or not it is to be machine or human perception is important, and environmental and ambient conditions can be taken into consideration. Further, the more critical the messages, the higher level of contrast may be set.
  • FIG. 7A a method 95 for determining what is perceptible on a display is illustrated.
  • a message is written to the display as shown in block 96.
  • method 95 is focused and directed to determining, capturing, and creating a historical record of what was actually displayed and its perceptibility.
  • block 97 detects the state of the pixels on the display. In some cases, this could be all the pixels, and in other cases it may be a subset of pixels related to the intended message. Those pixels are evaluated as shown in block 98 to determine whether they are a first color, a second color, somewhere in between.
  • the types of messages that are displayable on the display may mean that some of the pixels are not crucial to any possible message on the display. In that case, whether or not a particular pixel is at its intended state is inconsequential to the actual message that could be perceived. That is, irrespective of the state of the pixel, it would create little or no ambiguity in the final message.
  • alarms can be set, additional display items set, or messages sent to third parties. It will be understood that other actions may be taken responsive to particular patterns.
  • the perceptible content may consist of a message that is different from the intended message, incorrect or misleading yet importantly it might be sensible given the circumstances. Or it might be completely devoid of meaning.
  • the term content should be construed broadly to encompass whatever is actually displayed independent of its coherence or meaning.
  • Clinical research organizations and healthcare professionals for example, need to know that their decision to dispense a drug or infuse a patient with blood can and will be evaluated on the basis of the information available to them when the decision was made (not before or after). It may not be enough for an intelligent label to know that the information displayed wasn't correct. A user may not be able to tell the difference (it may 'look' correct/reasonable). For example, the difference between an expiration date, temperature reading or access code that ends in a zero or an eight or a four or a nine is a single pixel (segment). For better or worse a user may make a decision and take an action based on the immediately available information that may be erroneous. A single pixel (segment) can also be the difference between a plus and a minus sign or the international OK/Go and Warning/Stop symbols.
  • Measurements of the electrical state of the pixels in a pixel-set can be used in conjunction with appropriate reference tables or character recognition technique/systems to determine the content displayed and the messages it contains, if any. Measurements of the electrical state of the pixels in a pixel-set can be used to reconstruct the content actually displayed. That reconstruction in turn can be viewed, interpreted, analyzed, evaluated etc. by a person (or persons) or machine. And in conjunction with associated time/date information, an accurate, if not exact, reconstruction of the content displayed at a past moment in time could be used to judge whether or not a message was sufficiently perceptible and understandable to support a decision or action.
  • Measurements of the pixels' electrical characteristics can be taken at any time: before and immediately after updates, periodically over time, or in response to a command. Such measurements can be used to compare the original visual state with one or more past ones or absolute references to determine how they've changed over time or when the contrast in absolute terms or relative to each other pixels has unacceptably diminished. In the latter case the intelligent label could refresh the pixels or issue an alert.
  • measurements can be taken and written to memory with numerical precision consistent with the accuracy of the measurement means and the pixel configuration (e.g. larger pixels are easier to measure), the number of pixels and number of measurements, and the power and memory available.
  • the measurements can also be translated into a set of variables consistent with their visual states e.g. black, white or neither black nor white (e.g. gray, indeterminate, transparent, semi-transparent or opaque).
  • These measurements can be compared over time to determine the stability/efficacy of the display and perceptible information (e.g. to environmental conditions, time). In this way, this process can be used to determine if the display in an intelligent label or other electronic device (e.g.
  • the systems and means used here can be to varying degrees local to the intelligent label or to a remote display.
  • an entity independent of the system owner or operator it is advantageous for an entity independent of the system owner or operator to be able to verify the presence, accuracy and perceptibility of messages at various moments in time, location or other conditions, especially when consumers are involved.
  • owner/operators of an electronic shelf label (ESL) system or electronically updatable price tags
  • retailers or their operators
  • ESL electronic shelf label
  • Retailers also have the ability to control the prices the consumer pays at check-out/the point-of-sale. At worst this creates an opportunity for abuse/fraud.
  • ESL electronic shelf label
  • Retailers also have the ability to control the prices the consumer pays at check-out/the point-of-sale. At worst this creates an opportunity for abuse/fraud.
  • Consumers, regulators and honest businesses have an interest in being able to simply and reliably verify the accuracy and consistency of the pricing messages actually used to make purchase decisions and payments.
  • the required process control can be accomplished in a number of ways.
  • One way is to separate or isolating microprocessor functions such that the retailer for example can update the display, but cannot interfere with automatic measurement of the pixel's electrical characteristics immediately thereafter.
  • the storage of the results and the algorithmic conversion into displayed information Nor would they be able to access that information or associate date/time ESL ID or product SKU etc.
  • microprocessor functions could be isolated, yet securely communicatively coupled as required within a single IC or split between two ICs. Control can partly be manifest over the driver circuitry because the update and monitoring functions would both preferably use the same electrodes.
  • the price charged for the item (SKU) at the POS and the time it was charged are typically printed on a receipt and electronically recorded/stored (with appropriate security, and preferably with a third party). Both the visual and electronic record (with proper security) can be electronically compared to the price displayed at the time (or most recently). This provides a secure framework for auditing pricing information or a 3rd party to act as a neutral
  • the intended messages would be advantageously displayed as composite images consisting of multiple pixels.
  • a symbol e.g. a 'dot'
  • icon, letter or number for example could be comprised of multiple smaller pixels in the appropriate state (color) versus a single large pixel.
  • an acceptable level of verification of the displayed messages may be achieved by determining the pixel-set that makes up the intended message (or a component of the intended message), sending appropriate signals to the pixels in the pixel-set to produce the electrical state that corresponds to the desired message, and then measuring the aggregate electrical state of a set of pixels that comprise the intended message.
  • That pixel set could be, for example, either all of the pixels that comprise the intended message, or in some cases a subset of the pixels that comprise the intended message.
  • the process then algorithmically compares the measured results of the pixel-set with the corresponding previously determined pixels that comprise the intended message. It would be desirable that the algorithm compensates for 'noisy' data to compensate for activation (write) errors and measurement (read) errors.
  • one or more pixels of the set of pixels that make up a large visual element e.g. a symbol, image (including a predetermined
  • alphanumeric text string may be measured and aggregated and used to represent the state of the visual element. Pixels may be sized according to the requirements (e.g. min size/shape).
  • the perceptibility of displayed messages, information, images and the like is directly related to the contrast between the pixels that make up the message.
  • the ability to perceive a message depends on the contrast between a first, visual or colored state (e.g. white, or less than white) and a second, colored state (either black, or less than black) of the pixels.
  • a first, visual or colored state e.g. white, or less than white
  • a second, colored state either black, or less than black
  • the perceptibility of a message is not dependent on both, or either color being 'pure' (e.g. 100% black or 100% white) and the differential being 100% (it will always be somewhat less). What matters in most cases is that the differential in contrast (or contrast ratio) between the two states is sufficient for the message to be perceptible - not the absolute states in and of themselves.
  • a variety of algorithmic relationships may be utilized, but by way of illustration only, a display with an 80% 'white' first colored state can be thought of as also having a 20% black first colored state, and an 80% black second colored state may be thought of as having a 20% white second colored state.
  • the differential in contrast between the two states would be 60%. The same would be true for a display with a 90% white first colored state and a 30% black second colored state.
  • a 60% differential in contrast is sufficient for a message to be perceptible, then a message would be perceptible on either displays (80/20 and 90/30).
  • a lower differential in contrast e.g. 50% would indicate that perceptibility of the message was limited or impaired.
  • the relative contrast of the two states is associated with a measureable characteristic.
  • a "contrast differential" can be used to verify or determine the visual state of a pixel or pixel-set and by extension the perceptibility a message.
  • optical states other than contrast such as color, may also be used separately or in combination.
  • Another way of looking at contrast is to consider a contrast ratio.
  • the human eye adjusts to the (average) light intensity in the image, by changing its pupil diameter (fairly quickly) and also light sensitivity of the retina (over several minutes). This is similar to a linear gain change in an (otherwise) linear photo detector. Simplistically, the eye sets the max intensity to the highest level of the pixels in the display (in practice average would be a better measure). Thus for the two cases: 80/20 would be normalized to 100/25, and 90/30 would be normalized to 100/33. It would therefore be easier for the eye to see the 100/25 (with a contrast ratio of 4: 1), than the 100/33 (with a contrast ration of 3 : 1).
  • a "contrast differential” as the term is used herein, is the difference between a first and second measurement of an electrical property of a pixel or pixel-set that corresponds to a first, visual ("colored”) state and a second, colored state.
  • contrast differentials being determined relative to each other subjectively (e.g. by human trials) and/or objectively (e.g. by measurement of light reflection, transmission, or absorption). Such determination can be made for each individual display (e.g. factory calibrated) or for each class of device, or other criteria.
  • all the pixels comprising the display are set to a first state where the pixels are colored to a first color (preferably the background color which is preferably white) and then a first measurement of an electrical characteristic is taken.
  • the pixel or pixel-set that comprises the desired message is set to a second state where the pixel or pixel-set is colored to a second color that contrasts with the first color and a second measurement of the electrical characteristic is taken.
  • the contrast differential is calculated between the two
  • the calculated contrast differential then may be algorithmically compared to one or more previously generated reference "contrast differential,” values, indexes or benchmarks).
  • the pixel, pixel-set or all of the pixels comprising the display is set to a first color, the first color being the background color (e.g. white).
  • the first color being the background color (e.g. white).
  • all the pixels in the display were set to a first state, color and especially the background color (white).
  • a subset of all the pixels in the display those that were known to surround the pixel set, could be used instead (and they could be set pre or post the setting of the pixel-set to the send color (black).
  • only the pixels surrounding the pixel-set that were last known (measured) to be of set of the second color could be used set to the first color, pre or post the coloring of the pixel-set.
  • the contrast differential is determined without setting or resetting the states of the pixels in the pixel-set. For example, to compare it to a previous contrast differential and determine if the message has been stable over the interim interval or the display's efficacy has been impaired.
  • the first color may be either dark (e.g. black) or light (e.g. white) and can be of colors other than black or white.
  • the relationship between the electrical characteristic and the perceptibility of the message may be linear or nonlinear.
  • Previously generated reference contrast differentials may be generated during the manufacturing process and supplemented by an optical verification system. Or, they may be generated at one or more times during the display's (and intelligent label's) life. As previously described, conditional rules/logic may be applied and actions taken in response to comparisons between contrast differentials.
  • the relationship between the optical state of a pixel and the corresponding electrically measured characteristic is required (e.g. for a given voltage or capacitance, there is a corresponding optical state). This information may be obtained by calibrating the electro-optic displays using automated means consisting of electrical
  • the information may be calibrated to compensate for different environmental conditions (e.g. temperature, pressure, or humidity).
  • an intelligent label may be advantageous for an intelligent label to create a verifiable visual alert/alarm based on the displayed message.
  • the visual alert/alarm is, unlike that produced by a reversible bistable electro-optic device, irreversible permanent or near permanent (like a photograph).
  • a red dot or other symbol or message could be displayed to visually, and verifiably alert the user that the message displayed by the bistable electro-optic device was either incorrect or potentially inaccurate.
  • the intelligent label comprises an integrated electro-optic display comprising a bistable electrophoretic layer and a permanently irreversible electrochromic layer (such as that described in patent application
  • Electrical noise is generated both internally from switching digital logic, as well as from external sources, e.g. nearby electrical components, RF sources, etc. that are coupled into the system through internal wiring or signal traces, antennas, etc. Noise may be mitigated through design techniques, e.g. ground planes, layout and filtering so that it is typically well below those of the activation signals.
  • the noise is typically well below that of the signals that switch the display elements. It may however be on par with electrical measurements of pixels intended to determine their state.
  • the display and associated electronics may take advantage of common-mode techniques (e.g common-mode noise rejection techniques) so that the common-mode techniques.
  • measurements "ride" on top of the noise to the extent feasible. Additionally, they may use averaging of multiple measurements and comparisons to average reference levels to determine a difference between measured and reference levels. Other signal processing techniques may also be used optimize the detection and measurement of pixels.
  • FIGs. 8-18 discussed below, show an example implementation for determining perceptibility for a bistable display. It will be understood that there are many methods and processes that can be used, and this represents just one of the ways to detect and report perceptibility.
  • FIG. 8 provides an overview diagram of the color codes used in a representative implementation.
  • the visual state of a pixel corresponds to an electrically measurable characteristic of the pixel (e.g. voltage, resistance, capacitance etc.).
  • these electrically measurable characteristics are divided into three ranges. One part of the range is mapped to one display color and another part of the range corresponds to a second color. Measurements that are between these range values correspond to an ambiguous reading.
  • the set of values can be divided into additional ranges that can be associated with additional colors. Measurement ranges can be separated enough reliably to identify color sets. These values can be read to ascertain the current display value and established to set the appropriate color value for a segment on the display.
  • FIG. 9 corresponds to a commonly used seven-segment display.
  • the typical seven-segment display is supplemented with a new ambiguity indicator, which can be set to display whether or not the seven segments are confidently displaying an intended message.
  • Each of the seven letter-coded segments can be individually addressed and set or read through the electrical characteristic used in the design.
  • the segments can take one of two colors.
  • a separate indicator can be used in order to communicate with the user of the display that the display reading for a particular character is ambiguous. This indicator can be set in the case that the read value of a segment within a character is ambiguous.
  • a single ambiguity indicator can be associated with an entire message. Further, as described earlier, or messages and alarms may be generated and communicated. It will be understood that the inverse can be also be created: a "certainty" or "confidence" measure, index and indicator etc.
  • FIG. 10 corresponds to a symbol table for a seven-segment display that maps segment color values to symbols.
  • the allowable symbols are 7, 8, 9, and r. These symbols are the intended result of color patterns on the seven-segment display.
  • a 1 indicates "black” and a 0 indicates the color "white.”
  • the first row in the table corresponds to segments A, B and C being colored black and the other segments being colored white, or, depending on the display characteristics, uncolored. Such a pattern would generate a 7. If all segments are colored, as in the second row, then an 8 should be set on the display.
  • Process 200 Identify Segment Color
  • Process 200 begins in process step 210 where the physical value of a single pixel segment (e.g. voltage, resistance, capacitance etc.) is assessed.
  • Process 200 then proceeds to process step 220.
  • This step maps the value read in process step 210 to the range values described above. In the case of the two color code display, this might be represented as "0", "1", or "2" for example.
  • process step 230 the result of this mapping is returned from the process.
  • Process 200 then ends as to that segment, but can be repeated until all the required segments (pixels) are read and a color determined.
  • Process 300 Build Symbol String, is diagrammed in FIG. 12. This process compiles a collection of segment values into a symbol string.
  • Process 300 begins in process step 310 where an index is set.
  • Process step 320 invokes process 200, Identify Segment Color for the identified segment. The returned segment color is saved in process step 330. The segment index is incremented in process step 340.
  • Process 300 then continues to process step 350, where it is determined whether this is the final segment of the display. If it is not, process 300 continues to process step 320. If this was the last segment, process 300 proceeds to process step 360 where the symbol string is returned. This symbol string represents the actual state of the segments as detected, and may include all the segments, or a subset of the segments. Process 300 then ends.
  • Process 400 Build Message String, is diagrammed in FIG. 13.
  • Process 400 begins in process step 410 where an index is set. This process is useful for messages that comprise multiple symbols.
  • Process 400 then proceeds to process step 420 where Process 300, Build Symbol String, is invoked.
  • Process 400 then continues to process step 430 where the symbol string identified is saved.
  • process step 440 the symbol index is incremented.
  • Process 400 tests whether this was the last symbol to be processed in process step 450. If this was not the last symbol, process 400 continues to process step 420. If it was the last symbol to be processed, process 400 proceeds to process step 460 where the message string, the set of symbols identified, is returned. Process 400 then ends.
  • Process 500 Display Message
  • Process 500 begins in process step 510 where the symbol index is set to 1.
  • Process 500 proceeds to process step 520 where process 600 (FIG. 15), Lookup Symbol, is performed.
  • Process 500 then proceeds to process step 530, where it is determined whether the result of Process 600 was ambiguous. If it was not, process 500 proceeds to process step 550, where the symbol is displayed. If it was, process 500 proceeds to process step 540 where the ambiguity display indicator is set. As indicated in the description of FIG. 9, depending on the display, the may be one indicator per symbol, one indicator per display or another configuration that allows for appropriate communication.
  • Process 500 then continues to process step 560, where the symbol index is incremented. Process 500 then proceeds to process step 570 where it tests to determine whether this was the last symbol to process. If it was not, process 500 continues to process step 520. If it was, process 500 terminates. If will be appreciated that ambiguity as to a particular segment, or even a particular symbol, may not result in an ambiguity to the overall message.
  • Process 600 Lookup Symbol, is diagrammed in FIG. 15.
  • Process 600 takes as input a symbol string.
  • Process 600 begins in process step 610 where a table index is set to 1. The table index is used to iterate over the Symbol Table.
  • Process 600 then proceeds to process step 620 where process 700 (FIG. 16), Build Symbol Mask, is invoked with the current symbol string.
  • the result of Process 700 (FIG. 16) is a bit string mask. This mask has a zero in those symbol positions that are ambiguous.
  • Process 600 then proceeds to process step 630 where the symbol mask is logically A Ded with the symbol table entry to create a masked table entry. The result of process step 630 is then logically XORed with the symbol string.
  • Process 600 then proceeds to process step 650 where this bit string is tested. If it is not zero, this table entry is not a match for the symbol string and Process 600 proceeds to process step 675 where the table index is incremented. [0123] If the test in process step 650 was true, the symbol string was a match and Process 60 proceeds to process step 660. Where the table symbol is added to the Matching Symbol List. Process 600 then proceeds to process step 665 where the length of the Matching Symbol List is tested. If the length is greater than 1, that is, there has been more than one match for the symbol string identified, Process 600 proceeds to process step 670 where an ambiguity indicator for the symbol string is set. Process 600 then proceeds to process step 675. In process step 665, if the number of matching symbols is 1, process 600 proceeds to process step 675.
  • Process 600 then proceeds to process step 680 where the table index is compared to the length of the symbol table to determine whether this was the last table entry. If it is not, Process 600 proceeds to process step 620. If it is the last entry, Process 600 proceeds to process step 690 where the symbols from the table that matched the symbol string are returned. Process 600 then ends.
  • Process 700 Build Symbol Mask, is diagrammed in FIG. 16.
  • Process 700 takes as input a Symbol String and builds a bit mask. This bit mask has a 1 for every segment that has an unambiguous read and a 0 for every segment in which the segment string value is ambiguous.
  • Process 700 begins in process step 710 where the segment index (SI) is set to 1.
  • Process 700 proceeds to process step 720 where the value of the Symbol String at the SI position is ambiguous. If the Symbol String at this position is ambiguous, Process 700 proceeds to process step 760 where the mask bit at position SI is set to 0.
  • Process 700 then proceeds to process step 740.
  • process 700 proceeds to process step 730 where the Mask bit at position SI is set to 1. Process 700 then proceeds to process step 740 where the segment index is incremented. Process 700 then proceeds to process step 750. In process step 750 the SI is compared to the Symbol String length. If this was not the last symbol, Process 700 proceeds to process step 720. If it was the last segment in the Symbol String process 700 proceeds to process step 700 where the symbol mask is returned. Process 700 then terminates.
  • FIG. 17 shows examples of color indicator values, a symbol string, and a message string.
  • Process 800 Message Processing, is an asynchronous process driven by a timer or external interrupt.
  • Process 800 begins in process step 810 where it waits on a timer interrupt. Once the timer is triggered, Process 800 continues to process step 820 where process 400, Build Message String, is invoked. Process 800 then continues to process step 830 where the new message string is compared to the previous message string. If the new message string is equal to the previous message string, Process 800 proceeds to process step 810. If the new message string is not equal to the old message string, Process 800 continues to process step 840, where the changed message is logged.
  • the log entry for the message can include a date and timestamp, the message string, and other sensor information that may be both available and relevant (e.g., temperature) for the given device configuration and context.
  • This log entry can be saved in local device memory, external storage device or can be transmitted to a remote site for storage and further processing.
  • Process 800 then continues to process step 850 where process 500, Display Message is invoked. Process 800 then continues to process step 860 where the current message string is saved as the reference message string for subsequent comparisons.
  • Process 800 waits for a new message event. This event is device dependent and may be triggered by local sensors or may be externally triggered for purposes of setting the display configuration. Once triggered, Process 800 continues to process step 880 where the message for the event is accessed. This access may be through a lookup table based on possible events, may be supplied by an external source, or may be constructed based upon multiple sources of information available to the device. Process 800 then continues to process step 830.
  • Bistable electrophoretic displays typically employ an electric switching (or write) signal applied to a pair of addressing pixel electrodes that is characterized by a square pulse with specific voltage amplitude, polarity, and duration.
  • the application of such a pulse forms an electric field within the compartments containing the ink particles and suspension fluid that causes the charged particles to migrate toward the walls of the compartment in, or in opposite, direction of the field depending of the charge of the particles.
  • the migration speed of the particles is to first order proportional to the applied field, but may also be non-linear with respect to the applied field and exhibit a threshold in the electrical field, i.e., a minimum field required to cause migration, depending on the selection of the type of ink particle, its sticking properties to one another and the compartment wall, as well as, the rheology of the suspension fluid.
  • a threshold in the electrical field i.e., a minimum field required to cause migration, depending on the selection of the type of ink particle, its sticking properties to one another and the compartment wall, as well as, the rheology of the suspension fluid.
  • the application of a single write pulse for electrophoretic displays can, however, also be broken in into a series of smaller effect pulses accumulatively achieving a similar switching effect.
  • the methods and systems of applying smaller effect pulses to determine the state of a pixel in an electrophoretic display are disclosed.
  • Such smaller effect pulses hereinafter referred to as perturbation pulses, have a smaller cumulative effect than that of a nominal write pulse required to reliably switch the pixel state of an electrophoretic display and preferably are of a magnitude as to not significantly change the display state or the displayed message.
  • the effect of the perturbation pulses would preferably not change the display state more than that associated with shorter term settling or longer term degradation of the display state, or such that the message on the display would be compromised.
  • the system for electrical display state determination comprises the following
  • a display medium having at least one addressable display pixel capable of displaying at least two stable optical states, the display pixel having a first and a second addressable electrode, the first electrode being pixelated containing a pixel corresponding to the addressable display pixel;
  • a signal generator for applying at least a first electrical signal to the first electrode and a second electrical signal to the second electrode (a perturbation pulse);
  • a processor for determining the optical state of the display pixel from at least the detected electrical characteristic can be integrated into a self-contained display/state determination system.
  • the processor may preferably be external to the other components, with an added communication system (e.g., hardwired or wireless).
  • the signal generator produces the perturbation pulses, which may be selected to have the same nominal voltage amplitude as that of the write pulses of the display medium. However, a smaller or a higher amplitude may be selected with an appropriate selection of the pulse duration.
  • the perturbation pulses may further have a multitude of amplitudes, arbitrary waveforms, durations, or AC components.
  • the perturbation pulses may also be preconditioned by a series of AC pulses in order to overcome any significant sticking condition with the ink particles, to provide for more consistent or distinct current transients.
  • the delay in-between consecutive pulses may be selected as appropriate with or without the application of a DC bias.
  • the perturbation pulses such that the S R of the induced transient currents are sufficient for reliably characterization, in particular, for cases in which the pixel areas or the quantity of charged ink particles within the pixel are small.
  • the application of the perturbation pulses can be to a set of electrodes configured around the each ink compartment (microcapsule), but favorably to a set of electrodes congruent with at least one pixel of the display. Even more preferable is to apply the perturbation pulses to the same set of electrodes used by the write signal, which may include a common electrode on one side of the display.
  • the perturbation pulses may be calibrated or compensated based on the temperature of the display, the size of the pixel, pixel to pixel variation, or pixel dependent stray capacitance.
  • the temperature of the display may be determined by a separate sensor integral to the display, preferably near the display layer itself, or indirectly through a characteristic of the display (e.g., leakage current) which is coupled to the temperature behavior of the display.
  • the calibration scheme may be based on self-calibration or by use of off-line external optical detection such as a spectrophotometer.
  • the induced transient current can be measured and its characteristics be determined in the detection circuit, e.g., using threshold detection. Such characteristics may include the peak current, average current, time to half peak current, or temporal integration of the current (charge). It may further be preferable to only determine its characteristics based on a portion of the transient current response (i.e., within a determination window). For instance, the determination window may be a certain fraction of the total transient duration aligned with the leading, the trailing, or some middle part of the transient duration.
  • the induced transient current and its characteristic depends not only on the state of the display and the specifics of the applied perturbation pulse, but also on the detailed properties of its physical and electrochemical composition and resulting electrophoretic behavior, including but not limited to the choice of suspension fluid, selection of ink particle(s), additives such as surfactant (and resulting micelles), and degree of sticking of the ink particle(s) in the particular state of the display at which the perturbation pulse is applied.
  • the state of the pixel can be inferred and the functionality and integrity of the display pixel be assessed.
  • a series of restoring perturbation pulses can optionally and subsequently be applied to reset the display pixel to its original state, or to the original intended state.
  • the mobility of the charged ink particles and associated micelles within the suspension fluid in the microcapsules may be desirable to optimize the mobility of the charged ink particles and associated micelles within the suspension fluid in the microcapsules, and to minimize any leakage currents. For instance, it may be desirable to enhance the current transients such that the distinct display states can more readily be differentiated. This may further be done within the constraints of available switching voltage amplitude and selected perturbation pulse duration in relation to the write pulse duration. For systems with more than one type of ink particle, it may be advantageous to independently optimize the mobilities of the several types of particles.
  • the detection of the induced transient currents by the perturbation pulses for reliable determination of the state of the display is impacted by systematic and random noise. It is therefore desirable to not only reduce electronics noise (e.g., employ common mode noise reduction techniques), but also to reduce variation induced by the electrophoretic display mechanism itself. For instance, it is desirable to control the size, symmetry, density, charge and distribution of the ink particles, the microcapsules (e.g. diameter and wall thickness), and any other layer/material in-between the electrodes of the display.
  • Figure 19A illustrates a cross-section of a typical construction of an electrophoretic display 900 with microencapsulated 901 ink particles.
  • ink particles 902 and here assumed to have a positive charge there are two types of ink particles contained within each capsule corresponding to two colors and two display states: a first color here generated by white ink particles 902 and here assumed to have a positive charge; and a second color here generated by black ink particles 903 and here assumed to have a negative charge.
  • a potential difference 905 of some appropriate duration, the differently charged ink particles will move in opposite directions until all particles congregate at their respective side of the microcapsule.
  • both optical display states in this example dark and bright
  • Both the voltage amplitude and the duration of the write pulse at a particular temperature determine the final state of display. It may be desirable not to apply a too large of a combination of voltage amplitude and duration of the write pulse as this may create an overdriven condition in which the first state cannot easily be reverted to the complementary second state, or vice versa.
  • I verify will symbolically denote the response from the display pixel/segment when subjected to a verification pulse using any appropriate signal processing scheme. Based on the magnitude of I verify in response to an initial pulse and possibly additional pulses, the optical state can be deduced to be in one of the following states: dark/black, intermediate/grey, and bright/white.
  • FIG. 20 illustrates a flow diagram 950 for an exemplary display state verification process using this state perturbation approach.
  • This flow diagram outlines process steps to determine the whether the present optical state 951 presumed to be of a first color (here black/dark) is indeed correct 952, or rather is presumed to be that of the second color (here white/bright) 953, or if the state is determined to be that of an intermediary color (here grey) 954.
  • a verification pulse of inverse polarity to that of write pulse for the presumed optical state is applied 955. If the resulting verification current, I verify, is lower (or equal) than a certain appropriate threshold, I t h, there is little or no movement of the ink particles indicating that the initially presumed optical state was incorrect, and rather now is presumed to be the
  • additional restore pulse(s) can be applied 959 iteratively (for example, n-times, where n is an integer) implying an original intermediate/grey state with a restored state with a first color of dark/black 954.
  • n is an integer
  • this scheme provides for a state refreshing capability during the state verification process at appropriate time intervals.
  • an m column by n row (m x n) matrix display requires a minimum of m + n connections.
  • passive matrix addressing for writing of a message
  • active matrix addressing architectures are typically better suited with favorable scalability and crosstalk performance.
  • Such active matrix displays require additional connections to control the active pixels (e.g., m + n +1 or m + 2n).
  • FIG. 21 shows a typical backplane pixel schematic 1000 of an AMEPD with a storage capacitor 1053 and a pixel electrode 1052 connected a front plane electrophoretic display layer 1050 (here shown as a bistable reflective layer) with a common front plane electrode 1051.
  • the write signal is connected to the back electrode 1052 (and storage capacitor 1053) via column (source) line 1060 and is controlled by the row address (gate) line 1070 through TFT switch 1054.
  • Such pixel TFTs are typically integrated on the backplane (which favorably also contains the electrodes) and can be fabricated using a multitude of materials and processes including, for example, amorphous silicon, polycrystalline silicon, nanocrystalline silicon, as well as, organic material-based which are printable, flexible, and roll- to-roll compatible.
  • the backplane pixel electronics including TFT(s) and capacitor(s)
  • electrodes, and connection lines may be opaque, whereas for transmissive or transreflective displays, and when alternatively employed as the front plane, the electrodes are at least partially transmissive with the pixel electronics comprising a small (opaque) pixel footprint (aperture) or also having a transmissive characteristic.
  • active matrix switches are described as TFTs, it can be appreciated that other technologies can be used, such as MEMS-based switches. More generally, transistors including TFTs are examples of electrical switches and MEMS-based switches are examples of electro-mechanical switches that may be advantageously used as part of the control circuitry.
  • AMEPDs For AMEPDs various time-multiplexed methods and addressing schemes may be applied to connect and control the signal source to the pixel electrodes.
  • a separate driver for each column (source line 1060) with each row accessed sequentially (using a gate line 1070) allows each pixel to update in parallel with other pixels of the same row.
  • the scanning frame time period i.e. the duration to sweep through all the rows of the display
  • EDPs electrophoretic displays
  • multiple sweeps of the pixels in each sequential row i.e., multiple frames
  • a new optical state e.g. from black to white.
  • the drive signal for the current row is maintained by one (or more) appropriately sized storage capacitor(s) 1053 electrically connected in parallel with the pixel electrodes, wherein the common side of the capacitor(s) on the backplane 1055 is connected to the front plane common electrode 1051 of the AMEPD.
  • Such a parallel time multiplexing scheme enables updating of all the pixels of the active matrix display of a duration comparable to that of an individual pixel in a direct addressing mode.
  • time-multiplexed schemes may additionally be utilized for pre-switching protocols (e.g. write in parallel: first all-white, then all-black, followed by all-white before writing a message consisting of black pixels on a white pixel background).
  • a display drive system for a AMEPD includes one high-voltage display driver for each of the m columns of the display all of which are frequently integrated in a column (source) driver chip, and one row (gate) driver chip that accesses the n rows of the display.
  • the column and row driver chips are further controlled by a timing generator.
  • the detection (sensing) circuitry can advantageously also employ active matrix addressing for electrical state determination of AMEPDs using the same electrodes as those used for writing. Such active matrix detection circuitry also allows for favorable scalability (keeping the number of electrode connections to a minimum) and significantly reduces the detection crosstalk between pixels.
  • FIG. 22 shows an embodiment of the present invention of a verifiable active matrix display 1110 comprising an m x n matrix display 1 120 with, for illustrational purposes, a cross- sectional view of a single matrix pixel 1130, further comprising an electrophoretic display layer 1050, a pixel electrode 1052, and a common electrode 1051.
  • the matrix pixel electrodes connect to the write-message signal generator 1140 (discussed above), which generates a write-message signal that creates a write-message electrical differential 1141 across the matrix pixel electrodes.
  • the matrix pixel electrodes also connect to a control circuitry 1160, which includes a detection signal generator 1165 constructed to generate a detection electrical signal (e.g. perturbation pulses) that creates a detection electrical differential 1171 across the electrodes.
  • the detection circuitry 1170 measures the electrical response 1171 (e.g. a voltage or transient current) to the detection electrical signal on a least one of the matrix pixel electrodes, wherein the electrical response is indicative of a current optical state of the matrix pixel.
  • the control circuit typically includes a timing controller (not explicitly shown in 1160), to control the temporal characteristics of the detection electrical signal and electrical response (e.g. measurement duration and delay from the detection electric signal start) and route detection electrical signals to all display pixels, as well as, the circuits and components that enable independent generation of detection electrical signals that create detection electrical differentials, including those that are located within the matrix pixels for detection purposes.
  • FIG. 23 shows another exemplary embodiment for a verifiable active matrix display 1200 comprising m columns and n rows (i.e., m x n matrix display 1210).
  • m separate detection signal generators (part of the control circuitry) and m separate detection circuits (column drivers) 1230 can be used (one for each column) with a row driver 1220 (also part of the control circuitry) to address each of the n rows.
  • the row driver 1220 may also provide detection signal generator functionality for the generation of the detection electrical signal, i.e., in addition to the detection signal generation function of the column driver.
  • These detection signal generators, detection circuitries and row driver may further be controlled by a timing controller 1240 (also part of the control circuitry).
  • the write-message signal generator and detection function may share some of the same components.
  • the write function may use the same signal generators, row driver, and timing controller as that of the detection.
  • the signal output characteristics for the write operation and the signal generator output for the detection operation are typically different (e.g. in pulse duration and/or amplitude).
  • All components shown in FIG. 22 may be configured as an integrated (self-contained) display/state determination system.
  • the processor 1150 and other components may be configured external to the display backplane, e.g. on a flexible substrate or circuit board electrically coupled to the backplane
  • the pixel specific storage capacitor 1053 used for maintaining the write signal level while the specific display row is not being accessed may also be utilized by the detection circuitry.
  • one or more separate storage capacitors along with associated in-pixel switching capabilities (e.g., additional and separate TFT switches to turn on or off each capacitor) may be used.
  • the sizing of the in-pixel capacitors can be optimized for both write and detection performance including factors such as the particular addressing and detection schemes, switching and detection speed, compensation for parasitic capacitances, leakage currents, non- ideal switching characteristics of employed TFTs, and operating temperature range.
  • the detection circuitry and/or detection algorithms can also be optimized to compensate for systematic differences with respect to row numbers (e.g., to compensate for increased stray capacitance with an increase in row number).
  • Example A AMEPD with row-sequential write scheme.
  • messages on AMEPDs are infrequently updated.
  • the time required to complete a row-sequential write scheme may be acceptable (i.e., in which a write for one row is fully completed before the start of the write the next row).
  • any delays inserted between perturbation pulses by specific algorithms can be executed while the other rows of the display are subjected to their respective perturbation pulses, allowing the detection algorithm to be executed with a substantially parallel scheme.
  • FIG. 24 An exemplary embodiment of a pixel schematic 1300 enabling a row-sequential write scheme is illustrated in FIG. 24. Note that the pixel schematic is simplified over embodiment 1000 shown in FIG. 21, as it does not contain a storage capacitor. In lieu thereof, parasitic capacitances are compensated for either through the detection circuitry or algorithmically. Although not specifically illustrated, in order to minimize write signal and detection crosstalk, TFTs with large non-linearity characteristics and small leakage currents are preferred (e.g. by cascading TFTs). Furthermore, the signal-to-noise ratio (SNR) of the detected signal and the resulting determination of the displayed message may be enhanced.
  • SNR signal-to-noise ratio
  • write and detection of messages containing lower resolution patterns compared to the resolution of the display can be achieved through grouped detection circuitry and/or algorithms (e.g. by combining multiple adjacent rows or columns). Such grouping may be fixed (e.g. application specific) or dynamic (e.g. adaptive to the type of image displayed or detected).
  • Example B AMEPD with switchable pixel storage capacitor.
  • FIG. 25 An alternative preferred embodiment 1400 is shown in FIG. 25, in which the storage capacitor 1453 can be switched on or off by a capacitor TFT switch 1457 via capacitor gate line 1480.
  • the storage capacitor 1453 With the capacitor TFT switch 1457 turned on, the storage capacitor 1453 is engaged (in parallel with the pixel electrode 1052 and common (front) electrode 1051), and high speed write operation can be achieved (similarly to embodiment 1000 in FIG. 21).
  • the state detection circuitry operates similarly to that of embodiment 1200 in FIG. 24, as discussed in Example A.
  • Example C AMEPD with switchable in-pixel control circuitry capacitor.
  • the charge for generating the perturbation pulse is stored by a control circuit capacitor 1553.
  • the control circuit capacitor may also provide the function of the pixel storage capacitor 1053 (of the write-message signal generator), or may be separate, e.g. with a smaller capacitance, with corresponding charge and control lines (not shown in FIG. 26).
  • capacitor e.g. thin film capacitor
  • other energy storage components may be used to store and generate energy for the detection electrical signal including a battery or power harvester.
  • the embodiment 1500 also includes a pixel electrode TTF switch 1557 to be able to electrically couple or decouple the control circuit capacitor 1553 from the pixel electrode 1052 via pixel electrode control line 1580.
  • the control circuit capacitor 1553 and any associated switches or components to control it are considered part of the control circuitry.
  • some of the control circuitry may advantageously be in common with the write signal generator (for instance pixel TFT switch 1454), there are specific components that are unique to the control circuitry including those in the column, row drivers, or timing controller.
  • control circuitry For detection purposes (on a row basis), the control circuitry initially charges the control circuit capacitor 1553 through source line 1060 with pixel TFT switch 1454 on (via control line 1070) and pixel electrode TFT switch 1557 off (via control line 1580). Note that in this embodiment during the detection process, all other rows are turned off via their respective pixel TFT switches. After a favorable level of charge has been achieved (for example, corresponding to say a voltage near + or - 5V or 15V) source line 1060 is switched by the control circuitry (e.g., at the column driver of the control circuitry) to the detection circuitry to be able to sense line 1060 (e.g. voltage). At this point the signal (voltage) level of the control circuit capacitor 1553 can be confirmed.
  • a favorable level of charge for example, corresponding to say a voltage near + or - 5V or 15V
  • source line 1060 is switched by the control circuitry (e.g., at the column driver of the control circuitry) to the detection circuitry to be
  • control circuit switches pixel electrode switch 1557 on and, after a specified time, off (via control line 1580), which collectively results in the generation of the detection electrical signal (perturbation pulse) that creates the detection electrical differential across the pixel electrodes.
  • the response to the detection electrical signal i.e. here the discharge of the control circuit capacitor 1553 across the pixel electrodes 1052 and 1051 is measured via line 1060 by the detection circuitry.
  • the detection circuitry can measure the response on line 1060 at or after a (first) delay from the start of the detection electric signal (perturbation pulse), as well as, a second time after a favorable (second) delay after the first measurement, to determine the rate of decay (e.g. in voltage) induced by the discharge of the detector storage capacitor and the optical state-specific response of the pixel.
  • Alternative measurements techniques may comprise continuous digital sampling and processing or analog integrators.
  • any delays inserted between individual perturbation pulses by specific algorithms can be executed while the other rows of the display are subjected to their respective perturbation pulses, allowing the detection algorithm to be executed with a
  • line 1060 in particular embodiment 1500 is used for both charging and detecting the response to the detection electrical signal, only one of these operations can be done in only one row at a time (although, all columns in parallel).
  • a dedicated detection line with a dedicated control line and a corresponding TFT switch can be added to the detection circuitry enabling detection on one row while charging of the control circuit capacitors by the control circuitry on another row (e.g. next row).
  • additional control and source lines could also be added to allow for writing and updating the optical states of a pixel row while detecting and/or charging the control circuit capacitors.
  • the noise level of the detection electrical signal may be minimized by the charging protocol used by the control circuitry. For instance, it may be advantageous to charge the control circuit capacitor incrementally or over a specific time period, e.g., corresponding to certain noise components (such as 50Hz or 60Hz). This would provide a detection electrical signal on a pixel level that is favorably stable by averaging out the noise component(s).
  • Example D AMEPD with switchable in-pixel control circuit capacitor and differential detection output.
  • embodiment 1600 includes additional detection circuitry comprising of a TTF switch 1656 controlling an additional detection line 1660. Together with detection (and source) line 1060, a differential detection circuitry can favorably measure the transient current response of the detection electrical signal (discussed in Example C).
  • the effective serial resistance of pixel electrode TFT switch 1657 is selected to achieve adequate electric potential differential between detection lines and resulting detection SNR. Note that the additional TFT switch 1656 is controlled with the same control line 1070 as pixel TFT switch 1454 as both are either on or off simultaneously.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)

Abstract

L'invention concerne, en bref, un procédé permettant de vérifier la perceptibilité visuelle d'un dispositif d'affichage. Un message voulu est écrit sur un dispositif d'affichage bistable. Des pixels qui comprennent des portions du message sont mesurés et évalués afin de déterminer si le message réellement affiché sur le dispositif d'affichage bistable était perceptible par un humain ou une machine. Dans certains cas, des informations concernant le message réellement perceptible à partir du dispositif d'affichage peuvent être stockées en vue d'une utilisation ultérieure. En réponse à la détermination du caractère perceptible ou non perceptible d'un message, des alarmes peuvent être réglées, un ou plusieurs tiers peuvent être avertis, ou des caractéristiques de dispositif d'affichage supplémentaires peuvent être réglées.
PCT/US2018/030797 2017-05-03 2018-05-03 Détermination électrique de messages sur un dispositif d'affichage électrophorétique WO2018204582A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP18794561.3A EP3619701A1 (fr) 2017-05-03 2018-05-03 Détermination électrique de messages sur un dispositif d'affichage électrophorétique

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201762500626P 2017-05-03 2017-05-03
US62/500,626 2017-05-03

Publications (1)

Publication Number Publication Date
WO2018204582A1 true WO2018204582A1 (fr) 2018-11-08

Family

ID=64016237

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2018/030797 WO2018204582A1 (fr) 2017-05-03 2018-05-03 Détermination électrique de messages sur un dispositif d'affichage électrophorétique

Country Status (2)

Country Link
EP (1) EP3619701A1 (fr)
WO (1) WO2018204582A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022029018A1 (fr) * 2020-08-03 2022-02-10 Elstar Dynamics Patents B.V. Modulateur de lumière, procédé de modulation de lumière et vitrage intelligent
US11809055B2 (en) 2019-02-04 2023-11-07 Elstar Dynamics Patents B.V. Optical modulator
US12007660B2 (en) 2021-06-24 2024-06-11 Elstar Dynamics Patents B.V. Light modulator, substrate comprising electrodes and smart glazing

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040014265A1 (en) * 2002-04-24 2004-01-22 E Ink Corporation Processes for forming backplanes for electro-optic displays
US20100225831A1 (en) * 2006-03-06 2010-09-09 Masanori Takeuchi Active-matrix substrate, display device, and television receiver
US20140139501A1 (en) * 2012-11-16 2014-05-22 E Ink Corporation Active matrix display with dual driving modes
US20170032721A1 (en) * 2015-07-31 2017-02-02 Chromera, Inc. Symbol Verification for an Intelligent Label Device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040014265A1 (en) * 2002-04-24 2004-01-22 E Ink Corporation Processes for forming backplanes for electro-optic displays
US20100225831A1 (en) * 2006-03-06 2010-09-09 Masanori Takeuchi Active-matrix substrate, display device, and television receiver
US20140139501A1 (en) * 2012-11-16 2014-05-22 E Ink Corporation Active matrix display with dual driving modes
US20170032721A1 (en) * 2015-07-31 2017-02-02 Chromera, Inc. Symbol Verification for an Intelligent Label Device

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11809055B2 (en) 2019-02-04 2023-11-07 Elstar Dynamics Patents B.V. Optical modulator
US12001114B2 (en) 2019-02-04 2024-06-04 Elstar Dynamics Patents B.V. Optical modulator
WO2022029018A1 (fr) * 2020-08-03 2022-02-10 Elstar Dynamics Patents B.V. Modulateur de lumière, procédé de modulation de lumière et vitrage intelligent
TWI807376B (zh) * 2020-08-03 2023-07-01 荷蘭商艾爾星動力學專利公司 光調變器、光調變器之方法及智能玻璃
US12007660B2 (en) 2021-06-24 2024-06-11 Elstar Dynamics Patents B.V. Light modulator, substrate comprising electrodes and smart glazing

Also Published As

Publication number Publication date
EP3619701A1 (fr) 2020-03-11

Similar Documents

Publication Publication Date Title
US10168298B2 (en) Electrically determining messages on an electrophoretic display
US10733913B2 (en) Intelligent label device and method
US10147098B2 (en) Symbol verification for an intelligent label device
US11410585B2 (en) Optically determining messages on a display
US10002359B2 (en) Intelligent adaptive label device and method
US10769642B2 (en) Intelligent adaptive label device and method
WO2018204582A1 (fr) Détermination électrique de messages sur un dispositif d'affichage électrophorétique
US11138721B2 (en) Symbol verification for an intelligent label device
US11205108B2 (en) Symbol verification for an intelligent label device
US10467935B2 (en) Electrically determining messages on an electrophoretic display
US10152905B2 (en) Symbol verification for an intelligent label device
EP3563146A1 (fr) Détermination électrique de messages sur un écran électrophorétique
US20220082871A1 (en) Device and Method to Fix a Message on a Display
US11475462B2 (en) Symbol verification for an intelligent label device
US10156763B2 (en) Device and method to fix a message on a display
US10891447B2 (en) Symbol verification for an intelligent label device
EP3465604A1 (fr) Vérification de symboles pour un dispositif étiquette intelligent

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18794561

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2018794561

Country of ref document: EP

Effective date: 20191203