Lighting device and projection device

1. A lighting device, comprising:

a light source for generating a blue excitation light;

a base board which comprises at least one segment located in the light path of the blue excitation light, wherein at least one of the at least one segment is a blue segment; and

a wavelength conversion material layer covering the blue segment, wherein the wavelength conversion material layer absorbs a part of the blue excitation light and emits a converted light whose color coordinates is within a pre-defined color area, wherein the pre-defined color area is a first color area which is formed by line segments, lines or curved lines which intersect end to end as follows: a line and its extension line formed by connecting color coordinate of the blue excitation light and the color coordinate (0.14, 0.03), a line segment between the color coordinate (0.14, 0.03) and color coordinate (0.18, 0.03), a line and its extension line formed by connecting the color coordinate of the blue excitation light and the color coordinate (0.18, 0.03), and a boundary curved line of the CIE 1931 color space of International Commission on Illumination, so that a mixed light emitted from the blue segment is formed by the converted light and the remaining blue excitation light which is not absorbed by the wavelength conversion material layer, wherein the color coordinate of the mixed light is closer to a pre-defined blue light color coordinate than the color coordinate of the blue excitation light.

2. The lighting device of claim 1 , wherein the blue excitation light is a blue laser light, wherein a peak wavelength of a spectrum of the blue laser light is larger than or equal to 430 nanometer (nm) and smaller than or equal to 465 nm.

3. The lighting device of claim 1 , wherein the wavelength conversion material layer comprises a green phosphor or a cyan phosphor or a yellowish green phosphor or a yellow phosphor or a mixture of multiple kinds of these phosphors.

4. A projection device, comprising the lighting device of claim 1 .

5. The lighting device of claim 1 , wherein the wavelength conversion material layer contains a scattering material.

6. The lighting device of claim 1 , wherein the pre-defined blue light color coordinate is located inside a rectangle area, and color coordinates of four vertexes of the rectangle area are respectively (0.14, 0.03), (0.18, 0.03), (0.14, 0.08) and (0.18, 0.08).

7. The lighting device of claim 6 , wherein the pre-defined blue light color coordinate is located on a line segment, and color coordinates of two endpoints of the line segment are respectively (0.155, 0.06) and (0.165, 0.06).

8. The lighting device of claim 1 , wherein the color coordinates of the converted light is within a second color area which is a subset of the first color area and is formed by line segments, lines or curved lines which intersect end to end as follows: a line and its extension line formed by connecting color coordinate of the blue excitation light and color coordinate (0.14, 0.08), a line segment between the color coordinate (0.14, 0.08) and color coordinate (0.18, 0.08), a line and its extension line formed by connecting the color coordinate of the blue excitation light and the color coordinate (0.18, 0.08), and a boundary curved line of the CIE 1931 color space.

9. The lighting device of claim 8 , wherein the color coordinates of the converted light is within a third color area which is a subset of the second color area and is formed by line segments, lines or curved lines which intersect end to end as follows: a line and its extension line formed by connecting color coordinate of the blue excitation light and color coordinate (0.155, 0.06), a line segment between the color coordinate (0.155, 0.06) and color coordinate (0.165, 0.06), a line and its extension line formed by connecting the color coordinate of the blue excitation light and the color coordinate (0.165, 0.06), and a boundary curved line of the CIE 1931 color space.

10. The lighting device of claim 1 , further comprising a light filter located on one side of the wavelength conversion material layer facing the blue excitation light for transmitting the blue excitation light and reflecting the converted light.

11. The lighting device of claim 10 , wherein the light filter is an interference coating on a surface of the base board, which transmits the excitation light and reflects the converted light.

12. The lighting device of claim 1 , further comprising a reflecting layer located on one side of the wavelength conversion material layer facing away from the blue excitation light for reflecting the blue excitation light and the converted light.

13. The lighting device of claim 12 , wherein the reflecting layer is attached to or coated onto a surface of the base board.

14. The lighting device of claim 12 , further comprising a light guiding device for transmitting the blue excitation light and reflecting the mixed light emitted from the wavelength conversion material layer which is formed by the converted light and unabsorbed remaining blue excitation light, wherein the mixed light is separated from an input light path of the blue excitation light of the light source to form the output light.

15. The lighting device of claim 1 , further comprising a driving device, wherein the wavelength conversion material layer and the base board are fixedly connected to the driving device respectively, and wherein the driving device drives the base board and the wavelength conversion material layer to move relatively to the blue excitation light.

16. The lighting device of claim 15 , further comprising a light filter located in an output light path of the mixed light, which is used to filter the converted light so that color coordinate of the mixed light is closer to or equal to the pre-defined blue color coordinate, wherein the light filter is fixedly connected to the driving device and moves synchronously with the wavelength conversion material layer.

17. The lighting device of claim 15 , further comprising a light filter located on one side of the wavelength conversion material layer facing the blue excitation light for transmitting the blue excitation light and reflecting the converted light, wherein the light filter is fixedly connected to the driving device and moves synchronously with the wavelength conversion material layer.

18. The lighting device of claim 15 , further comprising a reflecting layer located on one side of the wavelength conversion material layer facing away from the blue excitation light for reflecting the blue excitation light and the converted light, wherein the reflecting layer is fixedly connected to the driving device and moves synchronously with the wavelength conversion material layer.