ILLUMINATION APPARATUS

• US 20100194291A1
• Filed: 08/08/2008
• Published: 08/05/2010
• Est. Priority Date: 09/26/2007
• Status: Abandoned Application

• Current Assignee: Toshiba Lighting & Technology Corporation (Toshiba Corporation)
• Original Assignee: Toshiba Lighting & Technology Corporation (Toshiba Corporation)
• Inventors: Ishiwata, Tomoko
• Application Number:
  US12/679,913
• Publication Number:
  US 20100194291A1
• Time in Patent Office: Days
• US Class Current: 315/153
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 47/10 Controlling the light source

Abstract

An illumination apparatus includes an image sensor 11, an arithmetic unit 12, a control unit 13, and a light source unit 14. The light source unit 14 can irradiate at least red, green, and blue lights. Thee image sensor 11 photographs an object illuminated by the light source unit. The arithmetic unit 12 calculates color components distributed on the object on the basis of a photographed image. The control, unit 13 controls color lights of the light source unit according to the color components distributed on the object calculated by the arithmetic unit.

Claims

1-21. -21. (canceled)

22. An illumination apparatus comprising:

a light source unit configured to be capable of irradiating at least red, green, and blue lights;

an image sensor configured to photograph an object illuminated by the light source unit;

an arithmetic unit configured to calculate color components distributed on the object on the basis of a photographed image; and

a control unit configured to control color lights of the light source unit according to the color components distributed on the object calculated by the arithmetic unit.

23. The illumination apparatus according to claim 22, wherein

the arithmetic unit calculates a distribution of colors corresponding to positions of portions of the object in the photographed image, and

the control unit controls the light source unit to generate the distribution of the colors corresponding to the positions on the object.

24. The illumination apparatus according to claim 22, wherein

the arithmetic unit detects colors of the object in the photographed image and determines a color included in the object most, and

the control unit controls the light source unit to create light of the color determined by the arithmetic unit.

25. The illumination apparatus according to claim 22, wherein the image sensor includes a filter approximated to an XYZ color matching function.

26. The illumination apparatus according to claim 22, wherein

the arithmetic unit detects R, G, and B gradation values of pixels in the photographed image and calculates a light mixing ratio in the light source unit according to the gradation values, and

the control unit controls the light source unit to reproduce the light mixing ratio determined by the arithmetic unit.

27. The illumination apparatus according to claim 22, further comprising means configured to select, in a photographed image, only a portion desired to be highlighted or a portion excluding a background as a target portion, wherein colors in a selected range can be highlighted.

28. The illumination apparatus according to claim 22, wherein the light source unit is a projection projector.

29. The illumination apparatus according to claim 26, wherein

the arithmetic unit includes:

calculating means configured to detect R, G, and B gradation values of pixels of the entire image or a part of the image photographed by the image sensor and calculate a percentage of the R, G, and B gradation values for each of the pixels;

achromatic color determining means configured to determine whether each of the pixels is a chromatic color or an achromatic color on the basis of the calculated percentage of the R, G, and B gradation values for each of the pixels; and

white determining means configured to distinguish between a white pixel and a gray pixel among the pixels determined as the achromatic color, and

the control unit controls, when a percentage of a number of pixels determined as the white pixels is equal to or higher than a predetermined percentage with respect to a number of pixels of the entire image or a part of the image, the light source unit such that light source colors by R, G, and B mixed light are set within a range of a deviation of 0.02 from a black body radiation locus.

30. The illumination apparatus according to claim 29, wherein

the achromatic color determining means determines that each of the pixels is the achromatic color when each percentage of the respective R, G, and B gradation values for each of the pixels in the calculating means is all equal to or higher than the predetermined percentage,

the white determining means calculates an average gradation value of the R, G, and B gradation values of the pixels determined as the achromatic color in the achromatic color determining means and, when the average gradation value is equal to or higher than a predetermined gradation value or equal to or higher than a standard value set in advance, determines that the pixels are white pixels, and

the control unit controls, when a percentage of the number of pixels determined as the white pixels is equal to or higher than the predetermined percentage with respect to the number of pixels of the entire image or a part of the image, the light source unit such that light source colors by R, G, and B mixed light are set within the range of a deviation of 0.02 from a black body radiation locus.

31. The illumination apparatus according to claim 30, wherein the predetermined percentage in the achromatic color determining means is 30%, the predetermined gradation value in the white determining means is 200 (when all gradations are 0 to 255), and the predetermined percentage in the control unit is 20%.

32. The illumination apparatus according to claim 30, wherein at least one of the predetermined percentage in the achromatic color determining means, the predetermined gradation value in the white determining means, and the predetermined percentage in the control unit can be variably set.

33. The illumination apparatus according to claim 26, wherein

the arithmetic unit includes:

a first storing unit configured to store positions of the pixels in the image photographed by the image sensor and the R, G, and B gradation values of the pixels;

a second storing unit configured to calculate and store positions of pixels in an image photographed next and a difference value between the R, G, and B gradation values of the pixels and the R, G, and B gradation values of the pixels at the time of the last photographing; and

means configured to compare an nth (n is an integer equal to or larger than

     1) difference value and an n+1 th difference value and detect movement of the illuminated object, and

a light modulation state at that point is maintained when there is no movement in the object according to a result of the comparison.

34. The illumination apparatus according to claim 33, wherein the means configured to detect movement of the object calculates a difference between the n+1 th difference value and the nth difference value and determines the movement of the object according to whether the calculated difference is smaller than a threshold set in advance.

35. The illumination apparatus according to claim 33, wherein the photographing of an image by the image sensor is performed every time the light mixing ratio determined by the arithmetic unit is reproduced.

36. The illumination apparatus according to claim 33, wherein the photographing of an image by the image sensor is performed while the light mixing ratio determined by the arithmetic unit is reproduced and every time the light mixing ratio is reproduced.

37. The illumination apparatus according to claim 26, wherein

the arithmetic unit includes:

calculating means configured to calculate xy chromaticities from the R, G, and B gradation values of the pixels of the entire image or a part of the image photographed by the image sensor; and

white determining means configured to distinguish, on the basis of the calculated xy chromaticity for each of the pixels, whether each of the pixels is a white pixel, and

the control unit controls, when a percentage of the number of pixels determined as the white pixels is equal to or higher than a predetermined percentage with respect to the number of pixels of the entire image or a part of the image, the light source unit such that light source colors by R, G, and B mixed light are set within a range of a deviation of 0.02 from a black body radiation locus.

38. The illumination apparatus according to claim 26 wherein

the image sensor includes an XYZ filter approximated to a CIE1931 color matching function,

the arithmetic unit includes:

measuring means configured to measure xy chromaticities of the pixels of the entire image or a part of the image photographed by the image sensor; and

white determining means configured to distinguish whether each of the pixels is a white pixel on the basis of the measured xy chromaticity for each of the pixels, and the control unit controls, when a percentage of the number of pixels determined as the white pixels is equal to or higher than a predetermined percentage with respect to the number of pixels of the entire image or a part of the image, the light source unit such that light source colors by R, G, and B mixed light are set within a range of a deviation of 0.02 from a black body radiation locus.

39. The illumination apparatus according to claim 37, wherein the predetermined percentage is 20%.

40. The illumination apparatus according to claim 26 wherein

the arithmetic unit includes:

means configured to set an initial value of a light mixing ratio of light source colors of the light source unit;

means configured to detect a change in the object over time on the basis of gradation values of the pixels of the image photographed by the image sensor; and

means configured to reset the light mixing ratio to the initial value when a change in the object is detected, and

the arithmetic unit detects R, G, and B gradation values of pixels of an image photographed in a light mixing state at the initial value and calculates a light mixing ratio of the light source unit according to the gradation values.

41. The illumination apparatus according to claim 40, wherein the means configured to detect a change in the object over time calculates a difference between an n+1 th (n is an integer equal to or larger than 1) difference value and an nth difference value and detects a change in the object according to whether the difference is smaller than a threshold set in advance.