JP2015034866A - Projector fluorescent wheel and projector light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector fluorescent wheel capable of improving an emission intensity, and a projector light-emitting device using the same.SOLUTION: The projector fluorescent wheel includes a ring-shaped transparent substrate 11, and a ring-shaped phosphor layer 12 provided on the transparent substrate 11. The transparent substrate 11 has a thickness of 0.6 mm or less.

Description

  The present invention relates to a fluorescent wheel for a projector and a light emitting device for a projector.

  In recent years, in order to reduce the size of a projector, a light emitting device using an LED (Light Emitting Diode) and a phosphor has been proposed. For example, Patent Document 1 discloses a projector using a light emitting device that includes a light source that emits ultraviolet light and a phosphor layer that converts ultraviolet light from the light source into visible light. In Patent Document 1, a fluorescent wheel produced by providing a ring-shaped phosphor layer on a ring-shaped rotatable transparent substrate is used.

JP 2004-341105 A

  A conventional light emitting device using a fluorescent wheel has a problem that light emission intensity is insufficient.

  An object of the present invention is to provide a fluorescent wheel for a projector that can increase the emission intensity and a light emitting device for a projector using the same.

  A fluorescent wheel for a projector according to the present invention includes a ring-shaped transparent substrate and a ring-shaped phosphor layer provided on the transparent substrate, and the thickness of the transparent substrate is 0.6 mm or less. .

  The thickness of the transparent substrate is preferably 0.1 mm or more.

  A glass substrate is mentioned as a transparent substrate.

  As a fluorescent substance layer, what has a glass matrix and the fluorescent substance disperse | distributed in the glass matrix is mentioned, for example.

  The phosphor layer is divided into a plurality of regions along the circumferential direction, and different types of phosphors may be included in the plurality of regions.

  A light-emitting device for a projector according to the present invention includes the above-described fluorescent wheel for a projector according to the present invention and a light source that irradiates excitation light onto a phosphor layer of the fluorescent wheel.

  ADVANTAGE OF THE INVENTION According to this invention, the emitted light intensity of the light-emitting device for projectors can be raised.

It is a perspective view which shows the fluorescent wheel for projectors of one Embodiment of this invention. It is sectional drawing which follows the AA line shown in FIG. It is a typical sectional view showing the reflective state of fluorescence when the thickness of a transparent substrate is thin. It is typical sectional drawing which shows the reflection state of the fluorescence when the thickness of a transparent substrate is thick. It is a typical side view showing a light emitting device for projectors of one embodiment of the present invention. It is a perspective view which shows the fluorescent wheel for projectors of other embodiment of this invention. It is a figure which shows the relationship between the thickness of a transparent substrate, and fluorescence peak intensity. It is a figure which shows the emitted light intensity in case (a) when the thickness of a transparent substrate is 0.72 mm, and (b) when the thickness of a transparent substrate is 0.23 mm.

  Hereinafter, preferred embodiments of the present invention will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Moreover, in each drawing, the member which has the substantially the same function may be referred with the same code | symbol.

  FIG. 1 is a perspective view showing a projector fluorescent wheel according to an embodiment of the present invention. 2 is a cross-sectional view taken along line AA shown in FIG. As shown in FIGS. 1 and 2, the fluorescent wheel 10 has a ring shape. The fluorescent wheel 10 is composed of a ring-shaped transparent substrate 11 and a ring-shaped phosphor layer 12 formed thereon. In the present embodiment, the phosphor layer 12 is composed of a glass matrix and phosphors dispersed therein. In the present embodiment, an inorganic phosphor is used as the phosphor.

  The glass matrix is not particularly limited as long as it can be used as a dispersion medium for a phosphor such as an inorganic phosphor. For example, borosilicate glass or phosphate glass can be used. The softening point of the glass matrix is preferably 250 ° C to 1000 ° C, and more preferably 300 ° C to 850 ° C.

  The phosphor is not particularly limited as long as it emits fluorescence upon incidence of excitation light. Specific examples of the phosphor include, for example, an oxide phosphor, a nitride phosphor, an oxynitride phosphor, a chloride phosphor, an acid chloride phosphor, a sulfide phosphor, an oxysulfide phosphor, and a halide. Examples thereof include one or more selected from phosphors, chalcogenide phosphors, aluminate phosphors, halophosphate phosphors, and garnet compound phosphors.

  The transparent substrate 11 is not particularly limited as long as it transmits the excitation light irradiated from the light source. Therefore, “transparent” in the transparent substrate 11 means transparent to excitation light. As the transparent substrate 11, for example, a glass substrate, a crystallized glass substrate, a ceramic substrate, a resin substrate, or the like can be used.

  In the present embodiment, the thickness t of the transparent substrate 11 shown in FIG. 2 is 0.6 mm or less. By setting the thickness t of the transparent substrate 11 to 0.6 mm or less, the emission intensity of the fluorescence emitted from the phosphor layer 12 can be increased. The thickness t of the transparent substrate 11 is more preferably 0.4 mm or less. In addition, when the thickness t of the transparent substrate 11 is too thin, the mechanical strength of the fluorescent wheel 10 is lowered, and it becomes difficult to handle practically. Therefore, the thickness t of the transparent substrate 11 is preferably 0.1 mm or more. More preferably, it is 0.2 mm or more.

  The reason why the intensity of light emitted from the phosphor layer can be increased by setting the thickness of the transparent substrate to 0.6 mm or less according to the present invention is not clear, but is considered as follows.

  FIG. 3 is a schematic cross-sectional view showing a fluorescence reflection state when the transparent substrate is thin. As shown in FIG. 3, the phosphor 13 in the phosphor layer 12 is excited by the excitation light 1 incident from the reflecting surface 11 a of the transparent substrate 11, and the fluorescence 2 is emitted from the phosphor 13. Alternatively, the excitation light 1 that has not been wavelength-converted is emitted from the phosphor layer 12 toward the transparent substrate 11. The fluorescence 2 emitted from the phosphor 13 and directed to the transparent substrate 11 or the excitation light 1 directed from the phosphor layer 12 to the transparent substrate 11 is reflected by the reflecting surface 11a of the transparent substrate 11 as shown in FIG. Incident on the body layer 12.

  FIG. 4 is a schematic cross-sectional view showing a reflection state of fluorescence when the transparent substrate is thick. As shown in FIG. 4, the phosphor 13 in the phosphor layer 12 is excited by the excitation light 1, and the fluorescence 2 is emitted from the phosphor 13. Alternatively, the excitation light 1 that has not been wavelength-converted is emitted from the phosphor layer 12 toward the transparent substrate 11. The fluorescence 2 emitted from the phosphor 13 and directed to the transparent substrate 11 or the excitation light 1 directed from the phosphor layer 12 to the transparent substrate 11 is reflected by the reflecting surface 11a of the transparent substrate 11, but as shown in FIG. When the transparent substrate 11 is thick, the reflected fluorescence 2 or excitation light 1 is emitted from the transparent substrate 11 toward the outside of the phosphor layer 12.

  Therefore, it is considered that when the thickness of the transparent substrate is increased, the ratio of light emitted from the phosphor layer to the outside increases. If the thickness of the transparent substrate is 0.6 mm or less according to the present invention, it is considered that the ratio of the light emitted from the phosphor layer to the outside can be reduced. Therefore, according to the present invention, it is considered that the emission intensity can be increased.

  FIG. 5 is a schematic side view showing a light emitting device for a projector according to an embodiment of the present invention. The projector light emitting device 31 according to the present embodiment includes a fluorescent wheel 10, a light source 20, and a motor 21 for rotating the fluorescent wheel 10. The ring-shaped fluorescent wheel 10 is attached to the rotating shaft 22 of the motor 21 so as to rotate in the circumferential direction about the central axis C of the rotating shaft 22.

  The excitation light 1 emitted from the light source 20 passes through the transparent substrate 11 of the fluorescent wheel 10 and enters the phosphor layer 12. The excitation light 1 incident on the phosphor layer 12 excites the phosphor, and the fluorescence 2 is emitted from the phosphor. Specific examples of the light source 20 include an LED light source and a laser light source.

  When a light source that emits blue light as excitation light is used as the light source 20, for example, a phosphor that is excited by blue light and emits yellow light can be used as the phosphor of the phosphor layer 12. As for the light emitted from the phosphor layer 12, only light having a desired wavelength can be extracted by a filter as necessary. A ring-shaped filter may be attached to the rotating shaft 22 and rotated in synchronization with the fluorescent wheel 10 to filter the emitted light.

  In the present embodiment, the fluorescent wheel 10 rotates in the circumferential direction. For this reason, the region that receives the excitation light 1 from the light source 20 is constantly moving, and even if the excitation light 1 is received and heated, it is immediately radiated. Therefore, the temperature rise of the fluorescent wheel 10 can be suppressed.

  In the fluorescent wheel 10 of the above embodiment, the same type of phosphor is contained over the entire surface of the phosphor layer 12. However, the present invention is not limited to such an embodiment. As in the embodiment described below, the phosphor layer 12 may be divided into a plurality of regions along the circumferential direction, and different types of phosphors may be included in each region.

  FIG. 6 is a perspective view showing a projector fluorescent wheel according to another embodiment of the present invention. The fluorescent wheel 10 shown in FIG. 6 has two sets of a first region 12a, a second region 12b, and a third region 12c. These regions are divided and provided in the circumferential direction as shown in FIG. For example, these regions correspond to regions that emit red, green, or blue light as fluorescence, and the fluorescent wheel 10 can be used as a color wheel. Also in this case, by setting the thickness of the transparent substrate 11 to 0.6 mm or less, the emission intensity of each fluorescence emitted from the first region 12a, the second region 12b, and the third region 12c is increased. be able to.

(About the effect of the thickness of the transparent substrate)
A glass substrate was used as the transparent substrate, and the influence of the thickness of the transparent substrate on the light emission intensity was examined. Each substrate having a thickness of 0.23 mm, 0.30 mm, 0.35 mm, 0.55 mm, and 0.72 mm was used. The excitation light was irradiated with light having a wavelength of 445 nm, and the intensity of the fluorescence peak having a wavelength of 540 nm emitted from the phosphor layer was measured using an integrating sphere having a diameter of 13 mm arranged on the phosphor layer.

  FIG. 7 is a diagram showing the relationship between the thickness of the transparent substrate and the fluorescence peak intensity. The fluorescence peak intensity on the vertical axis in FIG. 7 is a relative value where the fluorescence peak intensity is 1 when a substrate having a thickness of 0.72 mm is used. As is clear from the results shown in FIG. 7, it can be seen that the fluorescence peak intensity increases when the thickness of the transparent substrate is 0.6 mm or less. In particular, it can be seen that when the thickness of the transparent substrate is 0.4 mm or less, the fluorescence peak intensity is remarkably increased.

  FIG. 8 is a diagram showing the light emission intensity when the transparent substrate has a thickness of 0.72 mm (a) and when the transparent substrate has a thickness of 0.23 mm (b). As is clear from FIG. 8, the intensity of light emission in the wavelength region of 480 nm to 700 nm is increased by reducing the thickness of the transparent substrate.

DESCRIPTION OF SYMBOLS 1 ... Excitation light 2 ... Fluorescence 10 ... Fluorescence wheel 11 ... Transparent substrate 11a ... Reflecting surface 12 ... Phosphor layer 12a-12c ... 1st-3rd area | region 13 ... Phosphor 20 ... Light source 21 ... Motor 22 ... Rotating shaft 31 ... Light emitting devices for projectors

Claims (6)

A ring-shaped transparent substrate;
A ring-shaped phosphor layer provided on the transparent substrate,
A fluorescent wheel for a projector, wherein the transparent substrate has a thickness of 0.6 mm or less.   The fluorescent wheel for a projector according to claim 1, wherein the transparent substrate has a thickness of 0.1 mm or more.   The fluorescent wheel for a projector according to claim 1, wherein the transparent substrate is a glass substrate.   The said fluorescent substance layer is a fluorescent wheel for projectors as described in any one of Claims 1-3 which has a glass matrix and the fluorescent substance disperse | distributed in the said glass matrix.   5. The phosphor layer according to claim 1, wherein the phosphor layer is divided into a plurality of regions along a circumferential direction, and phosphors of different types are included in the plurality of regions. Fluorescent wheel for projectors. A fluorescent wheel for a projector according to any one of claims 1 to 5,
A light emitting device for a projector, comprising: a light source that emits excitation light to the phosphor layer of the fluorescent wheel.

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