ELECTRICALLY DETERMINING MESSAGES ON AN ELECTROPHORETIC DISPLAY

• US 20170292933A1
• Filed: 12/28/2016
• Published: 10/12/2017
• Est. Priority Date: 07/31/2015
• Status: Active Grant

• Current Assignee: Chromera, Inc.
• Original Assignee: Chromera, Inc.
• Inventors: Rilum, John, Atkinson, Paul
• Granted Patent: US 10,168,298 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 27/44713 Particularly adapted electric power supply
• CPC Class Codes: G01N 27/4473 by electric means
• CPC Class Codes: G01N 27/44769 Continuous electrophoresis, i.e. the sample being continuously introduced, e.g. free flow electrophoresis [FFE]
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G09G 2380/04 Electronic labels
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/007 Use of pixel shift techniques, e.g. by mechanical shift of the physical pixels or by optical shift of the perceived pixels
• CPC Class Codes: G09G 3/16 by control of light from an independent source
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167

Abstract

Briefly, a method for verifying the visual perceptibility of a display is provided. An intended message is written to a bistable display. Pixels that comprise portions of the message are measured and evaluated to determine if the message actually displayed on the bistable display was perceptible by a human or a machine. In some cases, information regarding the message actually perceivable from the display may be stored for later use. 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.

Claims

1. A verifiable display, comprising:

a set of display pixels, each pixel having at least two optical states and a first electrode and a second electrode;

a first electrical signal generator coupled to the first electrode and the second electrode, the signal generator constructed to create a first electrical differential between the electrodes to set a pixel into a desired optical state;

a second electrical signal generator coupled to the first electrode and the second electrode that at a later time creates a second electrical differential between the electrodes; and

a detection circuit coupled to one of the electrodes for measuring an electrical response to the second electrical signal.

2. The verifiable display of claim 1 wherein the first signal generator and the second electrical generator are the same.

3. The verifiable display of claim 1 wherein the pixels are electrophoretic.

4. The verifiable display of claim 1 wherein the signal generators are constructed to generate the first signal as a pulse and the second signal as a pulse shorter than the first signal pulse.

5. The verifiable display of claim 1 wherein the second electrical signal is selected to have a different electrical characteristic than the first electrical signal.

6. The verifiable display of claim 3a wherein the electrical characteristic is amplitude, duration, voltage, or waveform shape.

7. The verifiable display of claim 3a wherein the application of the second electrical signal does not alter the perceptibility of the desired optical state.

8. The verifiable display of claim 1 wherein the signal generators are constructed to generate the first signal as a write signal and the second signal as a perturbation signal.

9. The verifiable display of claim 1 wherein the perturbation signal is of the opposite polarity as the write signal.

10. The verifiable display of claim 1 wherein the perturbation signal is a set of pulses.

11. The verifiable display of claim 1 wherein the detection circuit is constructed to measure current flow.

12. The verifiable display of claim 1 further comprising a processor constructed to compare the electrical response to a predetermined threshold to determine the optical state of the pixel.

13. The verifiable display of claim 1 further comprising an environmental sensor to detect an environmental condition, and the detected environmental condition is used to compensate the second electrical signal.

14. The verifiable display of claim 13, wherein the environmental sensor is a temperature sensor arranged to detect the temperature of the display, a temperature sensor arranged to detect the temperature of ambient air, a pressure sensor, or a humidity sensor.

15. A method for verifying a display, comprising:

presuming a pixel on a display is in a first optical state of a plurality of possible optical states;

setting a threshold value according to the presumed first optical state;

applying a perturbation signal to the pixel;

measuring an electrical response of the pixel to the perturbation signal;

comparing the measured electrical response to the threshold value; and

determining, using the comparison, whether or not the pixel is in the presumed optical state.

16. The method according to claim 15, further including the steps of:

applying a write signal to the pixel at a polarity to set the pixel into the presumed optical state; and

applying the perturbation signal at the opposite polarity.

17. The method according to claim 16, wherein the step of applying the perturbation signal comprises applying a series of pulses.

18. The method according to claim 16, wherein the step of applying the perturbation signal comprises setting the perturbation signal to be at an amplitude smaller than the amplitude of the write signal.

19. The method according to claim 16, wherein the step of applying the perturbation signal comprises setting the perturbation signal to be at a voltage different than the voltage of the write signal.

20. The method according to claim 16, wherein the step of applying the perturbation signal comprises setting the perturbation signal to be at shorter duration than the duration of the write signal.

21. The method according to claim 16, wherein the step of applying the perturbation signal comprises setting the perturbation signal to be a different waveform than the waveform of the write signal.

22. The method according to claim 16, wherein the step of applying the perturbation signal wherein the time integral of the amplitude of the perturbation signal is smaller than the write signal.

23. The method according to claim 15, further including the step of applying a restore signal to the pixel after the electrical response has been measured.

24. The method according to claim 15, further including the steps of:

applying a write signal to the pixel at a polarity to set the pixel into the presumed optical state;

applying a restore signal at the same polarity as the write signal to the pixel after the electrical response has been measured;

measuring an electrical response of the pixel to the restore signal;

comparing the measured restore response to the threshold value to determine which of the plurality of possible optical states the pixel is actually in.

25. A method for verifying a display, comprising:

providing a pixel in an optical state;

applying a perturbation signal to the pixel;

measuring an electrical response of the pixel to the perturbation signal; and

determining, using the measured value, the optical state of the pixel.

26. The method according to claim 25, wherein the determining step comprises comparing the measured value against predetermined values.

27. The method according to claim 25, wherein the determining step comprises comparing the measured value against values in a look-up table.

28. An intelligent label, comprising:

a processor;

an electrophoretic display comprising a plurality of pixels;

a power source;

wherein the processor operates a method comprising;

applying a perturbation signal to one of the pixels;

measuring an electrical response of the pixel to the perturbation signal; and

determining, using the measured value, the optical state of the pixel.

29. The intelligent label according to claim 28, wherein the processor further operates the step of applying a write signal to the pixel to set the pixel in a presumed optical state.

30. The intelligent label according to claim 28, further comprising:

An environmental sensor to sense an environmental condition; and

wherein the perturbation signal is set, calibrated or adjusted responsive to the environmental condition.

31. The intelligent label according to claim 28, wherein the wherein the write signal is set responsive to time or an elapsed time.

32. The intelligent label according to claim 28, further comprising:

a communication circuit for receiving a message; and

wherein the write signal is set responsive to the message.

33. A verifiable display, comprising:

a set of display pixels, at least one of the pixels having an electrode;

an electrical signal generator coupled to the electrode, the signal generator constructed to apply a verification signal at the electrode;

a detection circuit coupled to the electrode for measuring an electrical response to the second signal.

34. The verifiable display according to claim 33, wherein the signal generator is further constructed to apply a write signal at the electrode to set the pixel into a desired optical state.