Devices and methods for using an infrared-projected capacitive (IR-PCAP) touchscreen

• US 10,444,907 B2
• Filed: 05/16/2017
• Issued: 10/15/2019
• Est. Priority Date: 05/16/2017
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Lakshmireddy, Karthik
• Primary Examiner(s): Butcher, Brian M
• Application Number:
  US15/596,774
• Publication Number:
  US 20180335892A1
• Time in Patent Office: 882 Days
• Field of Search: None
• 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 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A method for operating a touchscreen device is provided. The method identifies a status of the touchscreen device, by at least one processor, wherein the touchscreen device comprises at least a projected capacitive (PCAP) touchscreen mounted in front of a liquid crystal display (LCD) of the touchscreen device, an infrared (IR) touch sensor configured to generate an IR grid, a switch, and the at least one processor, and wherein the status comprises one of a default state lacking user touch input and a touch-state receiving active user touch input. When the status comprises the touch-state, the method adjusts the switch to enable user input selections via the PCAP touchscreen. When the status comprises the default state, the method retains a position of the switch, the position configured to disable user input selections via the PCAP touchscreen.

Claims

1. A method for operating a touchscreen device, the method comprising:

identifying a status of the touchscreen device, by at least one processor, wherein the touchscreen device comprises at least a projected capacitive (PCAP) touchscreen mounted in front of a liquid crystal display (LCD) of the touchscreen device, an infrared (IR) touch sensor configured to generate an IR grid, a switch, and the at least one processor, and wherein the status comprises one of a default state lacking user touch input and a touch-state receiving active user touch input;

when the status comprises the touch-state, adjusting the switch to enable user input selections via the PCAP touchscreen; and

when the status comprises the default state, retaining a position of the switch, the position configured to disable user input selections via the PCAP touchscreen.

2. The method of claim 1, wherein the method further comprises:

disabling user input selections via the projected capacitive (PCAP) touchscreen, to create the default state of the PCAP touchscreen, by;

detecting user touch input, via the PCAP touchscreen;

identifying a duration of time elapsed since detection of the user touch input; and

when the duration of time is greater than a threshold, connecting a plurality of conductive electrodes of the PCAP touchscreen to ground, by the switch, to enable formation of a shield capable of preventing electromagnetic interference (EMI) and radio frequency interference (RFI) during the default state;

wherein enabling the shield disables receiving the user input selections via the PCAP touchscreen to create the default state.

3. The method of claim 1, wherein enabling user input selections further comprises:

detecting an obstruction to the IR grid generated by the IR touch sensor; and

in response to detecting the obstruction, connecting a plurality of conductive electrodes of the PCAP touchscreen to the touch-controller of the touchscreen device, by the switch, to disable formation of a shield capable of preventing electromagnetic interference (EMI) and radio frequency interference (RFI) during the touch-state, wherein the touch-controller comprises the at least one processor;

wherein disabling the shield enables receiving the user input selections via the PCAP touchscreen.

4. The method of claim 1, further comprising:

sensing user-selected touch coordinates of the PCAP touchscreen, by a touch-controller of the touchscreen device, wherein the touch-controller comprises the at least one processor;

receiving user input selections indicated by the user-selected touch coordinates, via the IR touch sensor; and

presenting a response to the user input selections, by the PCAP touchscreen.

5. The method of claim 1, wherein identifying the status of the touchscreen device further comprises:

detecting at least one obstruction to the IR grid; and

identifying current use of the PCAP touchscreen, based on the at least one obstruction, wherein the current use indicates the touch-state, and wherein the status comprises the touch-state.

6. The method of claim 5, wherein the IR touch sensor is mounted in a bezel of the LCD and positioned in front of the LCD, wherein the IR touch sensor further comprises an infrared (IR) receiver, an infrared (IR) light emitting diode (LED), and infrared (IR) reflectors positioned on opposite sides of the LCD, and wherein the IR LED and the IR receiver are aligned in the bezel;

wherein the method further comprises producing multiple close reflections between the IR reflectors, by the IR LED and the IR receiver, to generate the IR grid capable of sensing an object approaching the PCAP touchscreen during touch operation; and

wherein the at least one obstruction comprises the object approaching the PCAP touchscreen.

7. The method of claim 1, wherein identifying the status of the touchscreen device further comprises:

detecting a lack of obstructions to the IR grid; and

determining that the PCAP touchscreen is not in current use, based on the lack of obstructions, wherein the default state is indicated by the lack of obstructions to the IR grid, and wherein the status comprises the default state.

8. A touchscreen device, comprising:

a projected capacitive touch (PCAP) touchscreen mounted in front of a liquid crystal display (LCD);

a switch coupled to the PCAP touchscreen, the switch configured to shift between a first position connecting the PCAP touchscreen to ground and a second position connecting the PCAP touchscreen to a touch-controller;

an infrared (IR) touch sensor configured to generate an IR grid; and

the touch-controller comprising at least a system memory element and a processor, the touch-controller communicatively coupled to the PCAP touchscreen, the switch, and the IR sensor, and the touch-controller configured to;

identify a status of the touchscreen device, wherein the status comprises one of a default state lacking user touch input and a touch-state receiving active user touch input;

when the status comprises the touch-state, adjust the switch to enable user input selections via the PCAP touchscreen, based on adjusting the switch; and

when the status comprises the default state, retain a position of the switch, the position configured to disable user input selections via the PCAP touchscreen.

9. The touchscreen device of claim 8, wherein the touch-controller is configured to:

disable user input selections via the projected capacitive (PCAP) touchscreen, to create the default state of the PCAP touchscreen, by;

detecting user touch input, via the PCAP touchscreen;

identifying a duration of time elapsed since detection of the user touch input; and

when the duration of time is greater than a threshold, connecting a plurality of conductive electrodes of the PCAP touchscreen to ground, by the switch, to enable formation of a shield capable of preventing electromagnetic interference (EMI) and radio frequency interference (RFI) during the default state;

wherein enabling the shield disables receiving the user input selections via the PCAP touchscreen to create the default state.

10. The touchscreen device of claim 9, wherein the PCAP touchscreen comprises one or more layers of glass;

and

wherein the plurality of conductive electrodes comprises an array of indium tin oxide (ITO) conductors positioned on the one or more layers of glass.

11. The touchscreen device of claim 9, wherein the PCAP touchscreen comprises one or more layers of polyethylene terephthalate (PET) plastic;

and

wherein the plurality of conductive electrodes comprises an array of indium tin oxide (ITO) conductors positioned on the one or more layers of PET plastic.

12. The touchscreen device of claim 8, wherein the touch-controller is configured to enable user input selections by:

detecting an obstruction to the IR grid generated by the IR touch sensor; and

in response to detecting the obstruction, connecting a plurality of conductive electrodes of the PCAP touchscreen to the touch-controller of the touchscreen device, by the switch, to disable formation of a shield capable of preventing electromagnetic interference (EMI) and radio frequency interference (RFI) during the touch-state, wherein the touch-controller comprises the at least one processor;

wherein disabling the shield enables receiving the user input selections via the PCAP touchscreen.

13. The touchscreen device of claim 8, wherein the touch-controller is further configured to:

sense user-selected touch coordinates of the PCAP touchscreen, by a touch-controller of the touchscreen device, wherein the touch-controller comprises the at least one processor;

receive user input selections indicated by the user-selected touch coordinates, via the IR touch sensor; and

present a response to the user input selections, via the PCAP touchscreen.

14. The touchscreen device of claim 8, wherein the touch-controller is configured to identify the status of the touchscreen device by:

detecting at least one obstruction to the IR grid; and

identifying current use of the PCAP touchscreen, based on the at least one obstruction, wherein the current use indicates the touch-state, and wherein the status comprises the touch-state.

15. The touchscreen device of claim 14, wherein the IR touch sensor is mounted in a bezel of the LCD and positioned in front of the LCD, and wherein the IR touch sensor further comprises:

an infrared (IR) receiver;

an infrared (IR) light emitting diode (LED); and

infrared (IR) reflectors positioned on opposite sides of the LCD, wherein the IR LED and the IR receiver are aligned in the bezel to produce multiple close reflections between the IR reflectors to generate the IR grid capable of sensing an object approaching the PCAP touchscreen during touch operation, and wherein the at least one obstruction comprises the object approaching the PCAP touchscreen.

16. The touchscreen device of claim 15, wherein the IR reflectors comprise IR reflective surface materials that include at least one of gold metal, gold-coated metal alloy, and gold-leaf sheets.

17. The touchscreen device of claim 15, wherein the IR reflectors comprise at least an aluminum IR reflective surface material.

18. The touchscreen device of claim 15, wherein the IR reflectors comprise at least a transparent acrylic plastic IR reflective surface material.

19. The touchscreen device of claim 8, wherein the touch-controller is configured to identify the status of the touchscreen device by:

detecting a lack of obstructions to the IR grid; and

determining that the PCAP touchscreen is not in current use, based on the lack of obstructions, wherein the default state is indicated by the lack of obstructions to the IR grid, and wherein the status comprises the default state.

20. A touchscreen system, comprising:

a projected capacitive touch (PCAP) touchscreen mounted in front of a liquid crystal display (LCD);

a switch coupled to the PCAP touchscreen, the switch configured to shift between a first position connecting the PCAP touchscreen to ground and a second position connecting the PCAP touchscreen to a touch-controller;

an infrared (IR) touch sensor mounted in a bezel of the LCD and positioned in front of the LCD, wherein the IR touch sensor further comprises an infrared (IR) receiver, an infrared (IR) light emitting diode (LED), and infrared (IR) reflectors positioned on opposite sides of the LCD, wherein the IR LED and the IR receiver are aligned in the bezel to produce multiple close reflections between the IR reflectors to generate an IR grid capable of sensing an object approaching the PCAP touchscreen during touch operation; and

the touch-controller comprising at least a system memory element and a processor, the touch-controller communicatively coupled to the PCAP touchscreen, the switch, and the IR sensor, and the touch-controller configured to;

identify a status of the touchscreen device, wherein the status comprises one of a default state lacking user touch input and a touch-state receiving active user touch input;

when the status comprises the touch-state, adjust the switch to enable user input selections via the PCAP touchscreen, based on adjusting the switch; and

when the status comprises the default state, retain a position of the switch, the position configured to disable user input selections via the PCAP touchscreen.