Device having multi-layered touch sensitive surface

• US 9,477,364 B2
• Filed: 11/07/2014
• Issued: 10/25/2016
• Est. Priority Date: 11/07/2014
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Fourie, Daniel, Wong, Amy Lai, Foo, Ken
• Primary Examiner(s): Moon, Seokyun
• Application Number:
  US14/535,631
• Publication Number:
  US 20160132145A1
• Time in Patent Office: 718 Days
• Field of Search: None
• 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 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• 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 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: H03K 17/96 Touch switches specially adapted for electronic time-pieces with no moving parts G04G21/08
• CPC Class Codes: H03K 17/9622 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 17/9647 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 2217/96031 Combination of touch switch and LC display
• CPC Class Codes: H03K 2217/960755 Constructional details of capacitive touch and proximity switches
• CPC Class Codes: H03K 2217/960785 with illumination

Abstract

A touchscreen display device may include a capacitive sensor disposed adjacent to a top surface of the display device, and a resistive sensor disposed below the capacitive sensor. A backlight may selectively illuminate a pattern on an inner side of the top surface of the display device, so that the pattern is visible from outside the display device when the backlight is activated, and is not visible when the back light is not activated.

Claims

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

detecting, by a capacitive sensor, a first user interaction with a predetermined portion of a touch surface on an exterior surface of a cover layer, the capacitive sensor being positioned adjacent to an interior surface of the cover layer;

in response to the first user interaction, activating a backlight and directing light generated by the backlight toward the cover layer;

detecting, by a resistive sensor positioned below the capacitive sensor, a second user interaction with the touch surface, the second user interaction including an actuation force applied to the touch surface that is sensed by the resistive sensor, and processing an input corresponding to the second user interaction

wherein the backlight is positioned below the resistive sensor, and wherein activating the backlight and directing light generated by the backlight toward the cover layer includes directing light from the backlight along a light guide layer positioned below the resistive sensor, and through the resistive sensor and the capacitive sensor toward the cover layer such that light generated by the backlight is emitted through translucent portions of a pattern layer provided on the interior surface of the cover layer, and is blocked by opaque portions of the pattern layer; and

de-activating the backlight such that light is not directed toward the predetermined portion of the touch surface,

wherein the translucent portions and the opaque portions of the pattern layer define a keyboard at the predetermined portion of the touch surface, and wherein activating a backlight includes transmitting light through the translucent portions of the keyboard such that the keyboard is visible through the cover layer.

2. The method of claim 1, further comprising determining if a current operation mode of the device includes a text entry field, and wherein activating a backlight includes activating a backlight when a text entry field is available for text input, and receiving text input via the keyboard.

3. The method of claim 1, wherein when de-activating the backlight, light is not transmitted through the translucent portions of the pattern layer such that the keyboard is not visible through the cover layer.

4. The method of claim 1, wherein detecting a first user interaction includes detecting a conductive object within a detecting zone of the capacitive sensor positioned below the cover layer.

5. The method of claim 4, wherein detecting a conductive object within a detecting zone of the capacitive sensor includes detecting the conductive object directly on the touch surface or detecting the conductive object within a predetermined distance from the touch surface, the conductive object including a user finger or hand.

6. A touch sensitive display device, comprising:

a cover layer including a touch sensitive surface on an exterior side surface of the cover layer;

a capacitive sensor disposed below an interior side surface of the cover layer;

a resistive sensor disposed below the capacitive sensor;

a pattern layer defined on the interior side surface of the cover layer, between the capacitive sensor and the cover layer;

a backlight;

a light guide layer disposed below the resistive sensor and optically coupled to the backlight; and

a controller configured to control the backlight in response to a user interaction sensed by the at least one sensor at the touch sensitive surface,

wherein the pattern layer includes translucent portions and opaque portions defining a keyboard, the translucent portions transmitting light generated by the backlight through the cover layer, and the opaque portions blocking light generated by the backlight from being transmitted through the cover layer, and wherein the controller is configured to control the backlight to transmit light through the translucent portions of the pattern layer while the opaque portions block light from being transmitted, such that the keyboard is visible at the touch sensitive surface of the cover layer.

7. The device of claim 6, wherein the resistive sensor is configured to detect a touch on the touch surface having an actuation force of less than or equal to 10 gram force.

8. The device of claim 6, the translucent portions having a transmissivity of 5%, and the opaque portions having a transmissivity of 0%.

9. The device of claim 6, wherein a luminance of the backlight is 250 Nits.

10. The device of claim 6, wherein a thickness of the cover layer is 0.15 mm and a transmissivity of the cover layer is 92% with 93% haze.

11. The device of claim 6, wherein the actuation force applied to the touch surface in the second user interaction is less than 15 gram force.

12. The device of claim 6, further comprising:

a reflector positioned below the light guide layer, the light guide layer and reflector guiding light generated by the backlight toward the cover layer.

13. The device of claim 6, wherein the capacitive sensor is configured to detect a conductive pointing object within a detection zone of the capacitive sensor.

14. The device of claim 13, wherein the capacitive sensor is configured to detect a user touch input on the touch sensitive surface of the cover layer, and to activate the backlight in response to the detected user touch input.

15. The device of claim 13, wherein the capacitive sensor is configured to detect a user hand or finger hover within a predetermined distance from the touch sensitive surface of the cover layer, and to activate the backlight in response to the detected hand or finger hover.

16. The device of claim 13, wherein the resistive sensor is configured to detect a touch on the touch surface having an actuation force of between 5 and 10 gram force.

17. The device of claim 6, wherein the pattern layer is printed on the interior side surface of the cover layer, and a thickness of the pattern layer is 0.01 mm, with the translucent portions including 5% transmissive ink and the opaque portions including 0% transmissive ink.