Module circuit, display module and method for providing an output signal

• US 10,360,874 B2
• Filed: 11/07/2012
• Issued: 07/23/2019
• Est. Priority Date: 11/29/2011
• Status: Active Grant

• Current Assignee: ams AG (Ams-Osram AG)
• Original Assignee: ams AG (Ams-Osram AG)
• Inventors: Trattler, Peter
• Primary Examiner(s): Boddie, William
• Assistant Examiner(s): Parker, Jeffrey
• Application Number:
  US14/361,289
• Publication Number:
  US 20140313175A1
• Time in Patent Office: 2,449 Days
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

A module circuit (11) comprises a sensor terminal (43) for feeding a sensor signal (SP) and a clock terminal (41) for feeding a pulse width-modulated clock signal (ST) having a first and a second clock phase (A, B). A signal processing circuit (40) of the module circuit (11) is coupled on the input side to the sensor terminal (43) and the clock terminal (41) and is designed to provide an output signal (SAL) dependent on the sensor signal (SP) that can be tapped in the first clock phase (A) and independent of the sensor signal (SP) that can be tapped in the second clock phase (B).

Claims

1. A module circuit, comprising:

a sensor terminal operable to feed a sensor signal;

a clock terminal operable to feed a pulse width-modulated clock signal having a first and a second clock phase;

a signal processing circuit comprising an analog-digital converter and an evaluation circuit, wherein the analog-digital converter is coupled on an input side to the sensor terminal and the clock terminal, wherein the evaluation circuit is connected to an output of the analog-digital converter, wherein the signal processing circuit is operable to generate an output signal based on the sensor signal and the clock signal, wherein generating the output signal comprises;

tapping the sensor signal during the first clock phase of the clock signal, and

integrating the sensor signal tapped during the first clock phase of the clock signal,

wherein the output signal is independent of the sensor signal during the second clock phase of the clock signal;

an ambient light sensor that is coupled to the sensor terminal, wherein the ambient light sensor is operable to generate the sensor signal and provide the sensor signal to the sensor terminal;

a proximity sensor coupled to the signal processing circuit;

a driver circuit that comprises a current regulator and is coupled on an input side to the clock terminal, wherein the signal processing circuit is connected on an output side to the driver circuit;

a light source that comprises at least one light-emitting diode and is connected to the current regulator; and

a voltage converter operable to provide a supply voltage that drops across a series circuit comprising the current regulator and the at least one light-emitting diode,

wherein the driver circuit is operable to;

receive the clock signal through the clock terminal, and

provide, using the current regulator, current to the light source during the second clock phase of the clock signal and not during the first clock phase of the clock signal.

2. The module circuit according to claim 1, wherein the signal processing circuit is operable to hold the output signal during the second clock phase of the clock signal constant at a value of the output signal at an end of the first clock phase of the clock signal.

3. The module circuit according to claim 1 or 2, wherein the signal processing circuit is operable to determine the output signal based on a trigger signal for a display.

4. The module circuit according to claim 1, wherein the signal processing circuit is operable to determine the output signal based on a number of activated pixels and a total number of pixels of a display.

5. The module circuit according to Claim 1, wherein the analog-digital converter is operable to integrate the sensor signal in an integration time period that is exclusively inside the first clock phase.

6. The module circuit according to claim 1, wherein the driver circuit is operable to switch off the light source during the first clock phase of the clock signal and to switch the light source on during the second clock phase of the clock signal.

7. The module circuit according to claim 6, wherein the driver circuit is operable to adjust a brightness of the light source based on the output signal.

8. The module circuit according to claim 1, wherein the signal processing circuit is operable to operate the proximity sensor during the first clock phase.

14. The module circuit according to claim 1, the proximity sensor comprising an infrared light-emitting diode and an infrared sensor.

15. The module circuit according to claim 1, wherein the ambient light sensor is a color sensor.

9. A display module, comprising:

a module circuit;

a display; and

a light source operable to provide back-lighting for the display,

wherein the module circuit comprises;

a sensor terminal for feeding a sensor signal;

a clock terminal for feeding a pulse width-modulated clock signal having a first and a second clock phase;

a signal processing circuit coupled on an input side to the sensor terminal and the clock terminal, wherein the signal processing circuit is operable to receive the sensor signal from the sensor terminal, receive the clock signal from the clock terminal, and generate an output signal based on the sensor signal and the clock signal, wherein generating the output signal comprises;

tapping the sensor signal during the first clock phase of the clock signal, and

integrating the sensor signal tapped during the first clock phase of the clock signal,

wherein the output signal is independent of the sensor signal during the second clock phase of the clock signal;

an ambient light sensor coupled to the sensor terminal, wherein the ambient light sensor is operable to generate the sensor signal and provide the sensor signal to the sensor terminal; and

a proximity sensor coupled to the signal processing circuit,

wherein the ambient light sensor is operable to obtain light through the display, and

wherein the signal processing circuit is operable to provide the output signal based on contents of the display by correcting the sensor signal according to the contents of the display.

10. The display module according to claim 9, wherein the display module is free of a light-impermeable barrier between the ambient light sensor and the display.

11. A method for providing an output signal, comprising:

receiving, at a signal processing circuit;

a sensor signal generated by an ambient light sensor from a sensor terminal, and

a pulse width-modulated clock signal from a clock terminal, wherein the clock signal has a first and a second clock phase;

generating, by the signal processing circuit, an output signal based on the sensor signal and the clock signal, wherein generating the output signal comprises;

tapping the sensor signal during the first clock phase of the clock signal, and

integrating, using an evaluation circuit and an analog-digital converter, the tapped sensor signal in an integration time period that is exclusively inside the first clock phase, wherein the analog-digital converter is coupled on the input side to the clock terminal and to the sensor terminal, and connects the sensor terminal to the evaluation circuit, and wherein the output signal is independent of the sensor signal during the second clock phase of the clock signal,

operating a proximity sensor by the signal processing circuit, wherein the proximity sensor is coupled to the signal processing circuit,

feeding the clock signal to a driver circuit comprising a current regulator and coupled on an input side to the clock terminal, the signal processing circuit being connected on an output side to the driver circuit;

providing, by a voltage converter, a supply voltage that drops across a series circuit comprising the current regulator and at least one light-emitting diode of a light source connected to the current regulator; and

providing, by the current regulator of the driver circuit, current to the light source during the second clock phase of the clock signal and not during the first clock phase of the clock signal.

12. A module circuit, comprising:

a sensor terminal operable to feed a sensor signal;

a clock terminal operable to feed a pulse width-modulated clock signal having a first and a second clock phase;

a signal processing circuit comprising an evaluation circuit and an analog-digital converter, wherein the analog-digital converter is coupled on an input side to the clock terminal and to the sensor terminal and connects the sensor terminal to the evaluation circuit, and wherein the signal processing circuit is operable to generate an output signal based on the sensor signal and the clock signal, wherein generating the output signal comprises;

tapping the sensor signal during the first clock phase of the clock signal, and

integrating the tapped sensor signal in an integration time period that is exclusively inside the first clock phase,

wherein the output signal is independent of the sensor signal during the second clock phase of the clock signal;

an ambient light sensor that is coupled to the sensor terminal, wherein the ambient light sensor is operable to generate the sensor signal and provide the sensor signal to the sensor terminal;

a proximity sensor coupled to the signal processing circuit;

a driver circuit that comprises a current regulator and is coupled on an input side to the clock terminal, wherein the signal processing circuit is connected on an output side to the driver circuit;

a light source that comprises at least one light-emitting diode and is connected to the current regulator; and

a voltage converter operable to provide a supply voltage that drops across a series circuit comprising the current regulator and the at least one light-emitting diode,

wherein the driver circuit is operable to;

receive the clock signal through the clock terminal, and

provide, using the current regulator, current to the light source during the second clock phase of the clock signal and not during the first clock phase of the clock signal.

13. A module circuit, comprising:

an ambient light sensor operable to generate a sensor signal;

a sensor terminal that is coupled to the ambient light sensor and operable to feed the sensor signal;

a clock terminal operable to feed a pulse width-modulated clock signal having a first and a second clock phase;

a signal processing circuit coupled on an input side to the sensor terminal and the clock terminal, wherein the signal processing circuit is operable to receive the sensor signal from the sensor terminal, receive the clock signal from the clock terminal, and generate an output signal based on the sensor signal and the clock signal, wherein generating the output signal comprises;

tapping the sensor signal during the first clock phase of the clock signal, and

integrating the sensor signal tapped during the first clock phase of the clock signal,

wherein the output signal is independent of the sensor signal during the second clock phase of the clock signal;

wherein the signal processing circuit comprises an evaluation circuit and an analog-digital converter which connects the sensor terminal to the evaluation circuit;

a single semiconductor body comprising the ambient light sensor and the signal processing circuit;

a driver circuit that comprises a current regulator and is coupled on an input side to the clock terminal, wherein the signal processing circuit is connected on an output side to the driver circuit;

a light source that comprises at least one light-emitting diode and is connected to the current regulator; and

a voltage converter providing a supply voltage that drops across a series circuit comprising the current regulator and the at least one light-emitting diode,

wherein the current regulator comprises a regulator transistor, a current sensor and an amplifier,

wherein a voltage converter output of the voltage converter is connected via the regulator transistor to the light source,

wherein the amplifier is coupled on an output side to a control terminal of the regulator transistor,

wherein an input of the amplifier is connected to an output of the current sensor,

wherein the current sensor is operable to deliver a signal representing a value of a current regulator current delivered by the current regulator to the light source.