SCANNING OF A TOUCH SCREEN

• US 20110043485A1
• Filed: 07/06/2007
• Published: 02/24/2011
• Est. Priority Date: 07/06/2007
• Status: Active Grant

• Current Assignee: Neonode, Inc.
• Original Assignee: Neonode, Inc.
• Inventors: Goertz, Magnus
• Granted Patent: US 8,471,830 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A user interface for receiving input commands in a mobile terminal includes a display device (D) for presenting visual information. Arrays of light sources (131, 132) and arrays of light detectors (141, 142) are arranged along respective first and second sides of the display device (D). Each array of light sources (131, 132) is configured to transmit light pulses (Λem_X, Λem_Y) over the display device (D), and each array of light detectors (141, 142) is configured to receive a part (Λin, Λin_Y) of the energy in the transmitted light pulses (Λem_X, Λem_Y). A processing unit (110) controls the light sources (131, 132) such that a respective light pulse (Λem_X, Λem_Y) is repeatedly transmitted from each source (LX1, . . . , LXn; LY1, . . . , LYm) in the arrays according to a predefined sequence. However, prior to transmitting the light pulse (Λem_X, Λsrri_Y). an initial measurement value (V1) registered by at least one detector (Dph) in the at least one array of light detectors (141, 142) is recorded. Thus, the initial measurement value (V₁) represents an ambience light intensity. Based on the initial measurement value (V₁) and a secondary measurement value (V₂) registered by at least one light detector (Dph) during emission of light from the light source (D_em), the processing unit (110) determines whether or not a light-obstructive object is present on the display device (D) between a given light source (D_em) in the arrays of light sources (131, 132) and at least one light detector (D_ph) in the at least one array of light detectors (141, 142).

Claims

1. An interface arrangement for receiving input commands in a mobile terminal, comprising:

a display device (D) adapted to present visual information to a user,

at least one array of light sources (131, 132) arranged along at least one first side of the display device (D), each array of light sources being configured to transmit light pulses (Λ

_emX, Λ

_emY) over the display device (D),

at least one array of light detectors (141, 142) arranged along at least one second side of the display device (D), each array of light detectors (141, 142) being configured to receive a part (Λ

_inX, Λ

_inY) of the energy in the transmitted light pulses (Λ

_emX, Λ

_emY), and

a processing unit (110) adapted to control the array of light sources (131, 132) such that a respective light pulse (Λ

_emX, Λ

_emY) is repeatedly transmitted from each source (LX1, . . . , LXn;

LY1, . . . , LYm) in the at least one array of light sources (131, 132) according to a predefined sequence, receive information pertaining to light energy registered by the detectors (PX1, . . . , PXn;

PY1, . . . , PYm) in the at least one array of light detectors (141, 142), and based thereon determine whether or not a light-obstructive object is present on the display device (D) between a given light source (D_em) and at least one light detector (D_ph) in the at least one array of light detectors (141, 142), characterized in that the processing unit (110) is adapted to;

record an initial measurement value (V₁) registered by at least one detector (D_ph) in the at least one array of light detectors (141, 142) prior to transmitting the light pulse (Λ

_emX, Λ

_emY), the initial measurement value (V₁) representing an ambience light intensity, and determine whether or not a light-obstructive object is present on the display device (D) based on the initial measurement value (V₁) and a secondary measurement value (V₂) registered by at least one light detector (D_ph) during emission of light from the light source (D_em).

2. The interface arrangement according to claim 1, wherein the display device (D) has a rectangular outline with four separate sides, and the at least one second side represents a respective side opposite to the at least one first side.

3. The interface arrangement according to claim 1, comprising a selection means (120) adapted to control the at least one array of light sources (131, 132) to emit light from a given light source (D_em) during a specified interval (T0).

4. The interface arrangement according to claim 3, wherein the processing unit (110) is adapted to cause pre-charging of at least one detector (D_ph) in the at least one array of light detectors (141, 142) in coordination with the light emitted from the given light source (D_em) such that the pre-charging is initiated at least a threshold time (T3) prior to a start of the specified interval (T0).

5. The interface arrangement according to claim 4, comprising a digitizing unit (150) configured to receive measurement values (V_x, V_Y) from the at least one array of light detectors (141, 142) and in response thereto deliver digital data (D_FB) to the processing unit (110).

6. The interface arrangement according to claim 5, wherein the processing unit (110) is configured to initiate the emission of light from the given light source (D_em) no earlier than after that (T4) digital data (D_FB) representing the initial measurement value (V₁) has been received by the processing unit (110).

7. The interface arrangement according to claim 5, wherein the processing unit (110) is configured to control the at least one array of light sources (131, 132) such that each light pulse (Λ

_emX, Λ

_emY) has a duration (T0) exceeding a conversion time of the digitizing unit (150) for producing the digital data (D_FB) based on the received measurement values (V_x, V_Y).

8. The interface arrangement according to claim 5, wherein the processing unit (110) is configured to cause pre-charging of at least one detector (D_ph) in the at least one array of light detectors (141, 142) in coordination with the light emitted from the given light source (D_em) such that the pre-charging (T2) is terminated no earlier than a delay time (TD) after expiry of the specified interval (T0) during which light is emitted from the given light source (D_em), the delay time (TD) representing a conversion time of the digitizing unit (150) for producing the digital data (D_FB) based on the received measurement values (V_X, V_Y).

9. A mobile terminal for processing digital data, characterized in that the terminal (T) comprises the interface arrangement according to claim 1.

10. A method of generating input commands to a mobile terminal having:

a display device (D) adapted to present visual information to a user, an array of light sources (131, 132) arranged along a first side of the display device (D) and configured to transmit light pulses (Λ

_emX, Λ

_emY) over the display device (D), and an array of light detectors (141, 142) arranged along a second side of the display device (D), the array of light detectors (141, 142) being configured to receive a part (Λ

_inX, Λ

_inY) of the energy in the transmitted light pulses (Λ

_emX, Λ

_emY), the method comprising;

controlling the array of light sources (131, 132) such that a respective light pulse (Λ

_emX, Λ

_emY) is repeatedly transmitted from each source (LX1, . . . , LXn;

LY1, . . . , LYm) in the array of light sources (131, 132) according to a predefined sequence,

receiving information pertaining to light energy registered by the detectors (PX1, . . . , PXn;

PY1, . . . , PYm) in the array of light detectors (141, 142), and based thereon

determining whether or not a light-obstructive object is present on the display device (D) between the light source (D_em) and at least one light detector (D_ph), characterized by

recording an initial measurement value (V₁) registered by at least one detector (D_ph) in the array of light detectors (141, 142) prior to transmitting the light pulse (Λ

_emX, Λ

_emY), the initial measurement value (V₁) representing an ambience light intensity, and

determining whether or not a light-obstructive object is present on the display device (D) based on the initial measurement value (V₁) and a secondary measurement value (V₂) registered by at least one light detector (D_ph) during emission of light from the source (D_em).

11. The method according to claim 10, comprising controlling the at least one array of light sources (131, 132) to emit light from a given light source (D_em) during a specified interval (T0).

12. The method according to claim 11, comprising pre-charging at least one detector (D_ph) in the at least one array of light detectors (141, 142) in coordination with the emission of light from the given light source (D_em) in such a manner that the pre-charging is initiated at least a threshold time (T3) prior to a start of the specified interval (T0).

13. The method according to claim 12, comprising:

digitizing measurement values (V_X, V_Y) received from the at least one array of light detectors (141, 142), and

producing digital data (D_FB) in response thereto.

14. The method according to claim 13, comprising initiating the emission of light from the given light source (D_em) no earlier than after that (T4) digital data (D_FB) representing the initial measurement value (V₁) has been received by the processing unit (110).

15. The method according to claim 13 comprising controlling the at least one array of light sources (131, 132) such that each light pulse (Λ

_emX, Λ

_emY) has a duration (T0) exceeding a conversion time for digitizing the measurement values (V_X, V_Y).

16. The method according to claim 13, comprising pre-charging the at least one detector