Determining the lighting conditions surrounding a device

• US 7,301,534 B2
• Filed: 05/23/2003
• Issued: 11/27/2007
• Est. Priority Date: 05/23/2002
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Runolinna, Mika
• Primary Examiner(s): LEWIS, DAVID LEE
• Application Number:
  US10/445,278
• Publication Number:
  US 20040036820A1
• Time in Patent Office: 1,649 Days
• Field of Search: 345 55-109, 345204-207, 345/590
• US Class Current: 345/207
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

The invention relates to a method for determining the lighting conditions surrounding a device comprising a transmissive color LCD display 1. In order to obtain a detailed information on the lighting conditions, it is proposed that the method comprises measuring within the device the intensity of light passing through the LCD display 1 from outside of the device, while no backlight is switched on. The light is color filtered by at least part of the LCD display 1 with a known color distribution. The invention equally relates to a device comprising means for carrying out the proposed method.

Claims

1. A method comprising:

measuring within a device comprising a transmissive color liquid crystal display for presenting information to a user, the intensity of light passing through said liquid crystal display from outside of said device, while no backlight is switched on, wherein said light is color filtered by at least part of said liquid crystal display with a known color distribution.

2. A method according to claim 1, wherein at least part of said liquid crystal display is alternatingly turned entirely to one of different colors for providing said color filtered light.

3. A method according to claim 1, wherein at least part of said liquid crystal display is turned to at least one known combination of different colors for providing said color filtered light.

4. A method according to claim 1, wherein the brightness of at least part of said liquid crystal display is additionally varied while measuring the intensity of said color filtered light.

5. A method according to claim 1, wherein basically only the intensity of light penetrating a selected part of said liquid crystal display is measured, and wherein only said selected part of said liquid crystal display is set to a known color distribution for said measurements.

6. A method according to claim 5, wherein only said selected part of said liquid crystal display is set to a known color distribution for said measurements.

7. A method according to claim 1, wherein basically the light penetrating the entire liquid crystal display is measured, and wherein basically the entire liquid crystal display is set to a known color distribution for said measurements.

8. A method according to claim 1, further comprising adjusting settings associated to a specific function of said device and/or to a specific function of a unit connected to said device, based on the measured light intensity of the color filtered light.

9. A method according to claim 8, wherein for adjusting said settings, said measured light intensity values are compared with stored keyvalues, each of said stored keyvalues being associated to predefined values for adjusting said settings.

10. A method according to claim 9, wherein said stored keyvalues and said predefined values are provided to said device by a network based service.

11. A method according to claim 8, wherein for adjusting said settings, said measured light intensity values are evaluated by a network based service providing values for adjusting said settings.

12. A method according to claim 8, wherein adjusting settings based on the measured light intensity of the color filtered light comprises adjusting settings for said liquid crystal display for each presentation.

13. A method according to claim 8, wherein adjusting settings based on the measured light intensity of the color filtered light comprises adjusting settings employed for calibrating a digital camera for an optimized taking of images, which digital camera constitutes said device, is integrated into said device or is connected to said device.

14. A method according to claim 1, wherein said method is performed automatically by said device.

15. A method according to claim 1, wherein said method is performed continuously during the operation of said device.

16. A method according to claim 1, wherein said method can be initiated by a user of said device.

17. A device comprising:

a transmissive color liquid crystal display for presenting information to a user;

a photometrical sensor placed within said device at a location to which light can penetrate from the outside of said device through said liquid crystal display, which photometrical sensor measures the intensity of light entering said device which was color filtered by said liquid crystal display; and

a processor for adjusting said liquid crystal display to provide a known color filtering for measurements by said photometrical sensor.

18. A device according to claim 17, wherein said photometrical sensor comprises a light resistor for measuring the intensity of received light and for outputting corresponding analogue measurement values, and an analogue-to-digital converter for converting analogue measurement values output by said light resistor into digital measurement values.

19. A device according to claim 17, wherein said photometrical sensor comprises a light diode outputting a binary value.

20. A device according to claim 19, wherein said photometrical sensor comprises in addition at least two resistors for enabling different threshold values for said light diode.

21. A device according to claim 17, wherein said photometrical sensor comprises a charge coupled device cell.

22. A device according to claim 21 comprising a digital camera, wherein said charge coupled device cell is used in addition by said digital camera for taking images.

23. A device according to claim 17, wherein said photometrical sensor is placed close to said liquid crystal display such that said photometrical sensor basically measures only light penetrating a selected part of said liquid crystal display.

24. A device according to claim 23, wherein said processor adjusts only said selected part of said liquid crystal display to provide a known color filtering for measurements by said photometrical sensor.

25. A device according to claim 17, wherein said photometrical sensor is placed at a distance to said liquid crystal display such that said photometrical sensor basically measures the light penetrating the entire liquid crystal display.

26. A device according to claim 17, wherein for measurements of the intensity of color filtered light by said photometrical sensor, said processor turns at least part of said liquid crystal display alternatingly entirely to one of different colors.

27. A device according to claim 17, wherein for measurements of the intensity of color filtered light by said photometrical sensor, said processor turns at least part of said liquid crystal display to at least one known combination of different colors.

28. A device according to claim 17, wherein during said measurements by said photometrical sensor, said processor additionally varies the brightness of at least part of said liquid crystal display.

29. A device according to claim 17, wherein said processor further adjusts settings associated to specific functional means of said device and/or to specific functional means of a unit connected to said device, based on measurements by said photometrical sensor.

30. A device according to claim 29, further comprising a data table for storing keyvalues corresponding to possible measurement values provided by said photometrical sensor, and for storing predetermined values for adjusting said settings, which predetermined values are associated to respective ones of said keyvalues, wherein said processor is able to access said data table.

31. A device according to claim 30, wherein said device can be connected to a network, said processor further for updating said values stored in said data table based on data received from a network to which said device is connected.

32. A device according to claim 17, wherein said processor further adjusts settings for said liquid crystal display for each presentation of information.

33. A device according to claim 17 comprising a digital camera, wherein said processor further adjusts settings employed for a calibration of said digital camera for optimizing the taking of images.

34. A device according to claim 17, wherein said processor automatically adjusts said liquid crystal display to provide a known color filtering for measurements by said photometrical sensor and evaluate received measurement values from said photometrical sensor.

35. A device according to claim 17, further comprising a user input for enabling a user to cause said processor to adjust said liquid crystal display to provide a known color filtering for measurements by said photometrical sensor and to evaluate received measurement values from said photometrical sensor.

36. A device comprising:

means for presenting color display information to a user;

photometrical means placed within said device at a location to which light can penetrate from the outside of said device through said means for presenting color display information to a user, which photometrical means are measuring the intensity of light entering said device which is color filtered by said means for presenting color display information to a user; and

means for adjusting said means for presenting color display information to a user to provide a known color filtering for measurements by said photometrical means.

37. A device according to claim 36, wherein said photometrical means comprises a light resistor for measuring the intensity of received light and for outputting corresponding analogue measurement values, and an analogue-to-digital converter for converting analogue measurement values output by said light resistor into digital measurement values.