SYSTEMS AND METHODS FOR CAPTURING IMAGES USING A PRESSURE SENSITIVE MEMBRANE

• US 20160292491A1
• Filed: 04/05/2016
• Published: 10/06/2016
• Est. Priority Date: 04/06/2015
• Status: Active Grant

• Current Assignee: Identification International, Inc.
• Original Assignee: Identification International, Inc.
• Inventors: Dickerson, Bryan D., Robinson, Christopher R., Cowen, William B. Jr., Fenrich, Richard K.
• Granted Patent: US 10,726,241 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/04144 using an array of force sensing means position sensing using the local deformation of sensor cells G06F3/0447
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence

Abstract

A total internal reflection based imaging system may include a light transmitting member having an imaging surface. A pressure sensitive membrane may be arranged on the imaging surface. The pressure sensitive membrane may include a top surface, a bottom surface, and an elastic deformable film forming at least a portion of the top surface. The imaging system may include a textured surface disposed between the pressure sensitive membrane and the imaging surface. An application of pressure on the top surface may deform the deformable film to reduce a distance between the deformable film and the imaging surface. A light source may be configured to emit a light towards the imaging surface such that reduced total internal reflection of the light occurs where the bottom surface of the pressure sensitive membrane contacts the imaging surface. A sensor may be configured to capture the light reflected from the imaging surface.

Claims

1. A pressure sensitive membrane including:

a top surface;

a bottom surface opposite the top surface; and

an elastic deformable film forming at least a portion of the top surface; and

a textured surface disposed between the bottom surface and an imaging surface of a light transmitting member, the textured surface being in contact with at least a portion of the bottom surface of the pressure sensitive membrane or in contact with at least a portion of the imaging surface, the textured surface holding the pressure sensitive membrane at a default position, the textured surface and/or the pressure sensitive membrane being formed such that an application of pressure at any location on the top surface of the pressure sensitive membrane deforms the deformable film to reduce a distance between the deformable film and the imaging surface at such location.

2. The pressure sensitive membrane of claim 1, wherein a refractive index of the elastic deformable film is identical or near identical to that of the light transmitting member.

3. The pressure sensitive membrane of claim 1, wherein the pressure sensitive membrane is formed from a polymer film having less than 20 μ

m thickness.

4. The pressure sensitive membrane of claim 3, wherein the polymer film includes one or more of parylene, urethane, polyester, fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), perfluoroalkoxy (PFA), and/or Kapton.

5. The pressure sensitive membrane of claim 1, wherein the textured surface includes one or more raised standoffs, a sinusoidal wave, a rough textured surface, a microcellular foam, and/or a non-porous layer.

6. The pressure sensitive membrane of claim 1, wherein the textured surface includes a plurality of nanowires.

7. The pressure sensitive membrane of claim 1, wherein the textured surface is cast from a surface of a mold.

8. A total internal reflection based imaging system comprising:

a light transmitting member having an imaging surface;

a pressure sensitive membrane arranged on the imaging surface, the pressure sensitive membrane including a top surface, a bottom surface opposite the top surface, and an elastic deformable film forming at least a portion of the top surface;

a textured surface disposed between the pressure sensitive membrane and the imaging surface, the textured surface being in contact with at least a portion of the bottom surface of the pressure sensitive membrane or in contact with at least a portion of the imaging surface, the textured surface holding the pressure sensitive membrane at a default position, the textured surface and/or the pressure sensitive membrane being formed such that an application of pressure at any location on the top surface of the pressure sensitive membrane deforms the deformable film to reduce a distance between the deformable film and the imaging surface at such location;

a light source configured to emit a light towards the imaging surface from a side of the imaging surface opposite the textured surface such that reduced total internal reflection of the light occurs at any location on the imaging surface at which the bottom surface of the pressure sensitive membrane contacts the imaging surface due to pressure exerted on the top surface of the pressure sensitive membrane; and

a sensor configured to capture the light reflected from the imaging surface.

9. The total internal reflection based imaging system of claim 8, wherein the light transmitting member is a prism or optical waveguide.

10. The total internal reflection based imaging system of claim 8, wherein a refractive index of the elastic deformable film is identical or near identical to that of the light transmitting member.

11. The total internal reflection based imaging system of claim 8, wherein the pressure sensitive membrane is formed from a polymer film having less than 20 μ

m thickness.

12. The total internal reflection based imaging system of claim 11, wherein the polymer film includes one or more of parylene, urethane, polyester, fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), perfluoroalkoxy (PFA), and/or Kapton.

13. The total internal reflection based imaging system of claim 8, wherein the textured surface includes one or more raised standoffs, a sinusoidal wave, a rough textured surface, a microcellular foam, and/or a non-porous layer.

14. The total internal reflection based imaging system of claim 8, wherein the textured surface includes a plurality of nanowires.

15. The total internal reflection based imaging system of claim 8, wherein the textured surface is cast from a surface of a mold.

16. A fluorescent or scattered light imaging system comprising:

a light transmitting member having an imaging surface;

a pressure sensitive membrane arranged on the imaging surface, the pressure sensitive membrane including a top surface, a bottom surface opposite the top surface, and an elastic deformable film forming at least a portion of the top surface;

a textured surface disposed between the pressure sensitive membrane and the imaging surface, the textured surface being in contact with at least a portion of the bottom surface of the pressure sensitive membrane or in contact with at least a portion of the imaging surface, the textured surface holding the pressure sensitive membrane at a default position, the textured surface and/or the pressure sensitive membrane being formed such that an application of pressure at any location on the top surface of the pressure sensitive membrane deforms the deformable film to reduce a distance between the deformable film and the imaging surface at such location;

a light source configured to emit a light towards the imaging surface from a side of the imaging surface opposite the textured surface such that reduced total internal reflection of the light occurs and enhanced fluorescent or scattered light emission occurs at any location on the imaging surface at which the bottom surface of the pressure sensitive membrane contacts the imaging surface due to pressure exerted on the top surface of the pressure sensitive membrane; and

a sensor configured to capture the enhanced fluorescent or scattered light emission from the imaging surface.

17. The fluorescent or scattered light imaging system of claim 16, wherein the light transmitting member is a prism or optical waveguide.

18. The fluorescent or scattered light imaging system of claim 16, wherein a refractive index of the elastic deformable film is identical or near identical to that of the light transmitting member.

19. The fluorescent or scattered light imaging system of claim 16, wherein the pressure sensitive membrane is formed from a polymer film having less than 20 μ

m thickness.

20. The fluorescent or scattered light imaging system of claim 19, wherein the polymer film includes one or more of parylene, urethane, polyester, fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), perfluoroalkoxy (PFA), and/or Kapton.

21. The fluorescent or scattered light imaging system of claim 16, wherein the textured surface includes one or more of raised standoffs, a sinusoidal wave, a rough textured surface, a microcellular foam, and/or a non-porous layer.

22. The fluorescent or scattered light imaging system of claim 16, wherein the textured surface includes a plurality of nanowires.

23. The fluorescent or scattered light imaging system of claim 16, wherein the textured surface is cast from a surface of a mold.

24. An electrical pressure sensor readout grid system comprising:

a pressure sensitive membrane arranged on an electrical acquisition surface, the pressure sensitive membrane comprising;

a top surface;

a bottom surface opposite the top surface;

an elastic deformable film with electrically active layers forming at least a portion of the top surface; and

electrically active layers forming at least a portion of the bottom surface of the pressure sensitive membrane contacting the electrical acquisition surface;

a textured surface disposed between the pressure sensitive membrane and the electrical acquisition surface, the textured surface being in contact with at least a portion of the bottom surface of the pressure sensitive membrane or in contact with at least a portion of the electrical acquisition surface, the textured surface holding the pressure sensitive membrane at a default position, the textured surface and/or the pressure sensitive membrane being formed such that an application of pressure at any location on the top surface of the pressure sensitive membrane deforms the elastic deformable film to reduce a distance between the elastic deformable film and the electrical acquisition surface at such location causing electrical properties of the electrically active layer to change; and

an electrical sensor readout grid configured to apply a current or voltage between electrodes of the electrical sensor readout grid at the electrical acquisition surface such that an electrical response occurs between electrodes at any location on the electrical acquisition surface at which the bottom surface of the pressure sensitive membrane contacts the electrical acquisition surface due to pressure on the top surface of the pressure sensitive membrane.

25. The electrical pressure sensor readout grid system of claim 24, wherein the pressure sensitive membrane is formed from a polymer film having less than 20 μ

m thickness.

26. The electrical pressure sensor readout grid system of claim 25, wherein the polymer film includes one or more of parylene, urethane, polyester, fluorinated ethylene propylene (FE P), ethylene tetrafluoroethylene (ETFE), perfluoroalkoxy (PFA), and/or Kapton.

27. The electrical pressure sensor readout grid system of claim 24, wherein the textured surface is cast from a surface of a mold.

28. The electrical pressure sensor readout grid system of claim 24, wherein the electrodes are arranged in a repeating fractal pattern.

29. The electrical pressure sensor readout grid system of claim 24, wherein the electrodes are located around perimeters of other electrodes.

30. The electrical pressure sensor readout grid system of claim 24, wherein the textured surface includes periodic or quasi-periodic raised features.

31. The electrical pressure sensor readout grid system of claim 24, wherein the electrical sensor readout grid is fabricated by a printing processes.

32. The electrical pressure sensor readout grid system of claim 24, wherein the pressure sensitive membrane comprises layers with controlled electrical properties including one or more of moderate resistance, high conductance, high dielectric constant, and/or high magnetic susceptibility.

33. The electrical pressure sensor readout grid system of claim 24, wherein the pressure sensitive membrane comprises a layer with a pressure sensitive air gap such that the application of pressure is measured based upon a change in capacitance of a region that includes the pressure sensitive membrane.

34. The electrical pressure sensor readout grid system of claim 24, wherein the pressure sensitive membrane comprises a layer with high conductance grounded to minimize a sensitivity of the electrical sensor readout grid to parasitic electrical properties of other layers of the pressure sensitive membrane or parasitic electrical properties of an object applying the application of pressure.

35. The electrical pressure sensor readout grid system of claim 24, wherein pressure sensors are separated from a measurement bias bus by a first set of indexing transistors, and each pressure sensor is separated from a read bus by a second set of indexing transistors, such that data from an array of pressure sensors are read from one isolated location regardless of an internal design of the pressure sensors.

36. The electrical pressure sensor readout grid system of claim 35, wherein each pressure sensor is separated from an input bus by a third set of indexing transistors, and each pressure sensor is separated from a output bus by a fourth set of indexing transistors, such that data from the array of pressure sensors are read from one isolated location regardless of the internal design of the pressure sensors.

37. The electrical pressure sensor readout grid system of claim 24, wherein pressure sensor data is acquired and stored into a local buffer at a first rate within the electrical pressure sensor readout grid system, and the pressure sensor data is retrieved and transmitted at a different rate from the first rate, such that the local buffer allows the pressure sensor data to be acquired and stored without interrupting the pressure sensor data from being retrieved and transmitted.

38. The electrical pressure sensor readout grid system of claim 37, wherein the pressure sensor data is hardwired into a dedicated memory allocation.

39. The electrical pressure sensor readout grid system of claim 37, wherein the pressure sensor data is input automatically into sequential memory locations.

40. The electrical pressure sensor readout grid system of claim 24, wherein input data is acquired and stored into a local memory structure at a first rate, and output data is retrieved and transmitted at a different rate from the first rate, such that the local memory structure allows the input data to be acquired and stored without interrupting the output data from being retrieved and transmitted.

41. The electrical pressure sensor readout grid system of claim 40, wherein the input data is acquired from different locations having similar format and array dimensions, wherein the input data from different locations is directed into a dedicated memory allocation.