JP2014164098A - Light emission device for projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emission device for a projector capable of increasing the use efficiency of a fluorescent body, and obtaining high luminance.SOLUTION: The light emission device for a projector includes: a ring-shaped fluorescent member 10; a light source 40 for irradiating the fluorescent member 10 which rotates in a circumferential direction with first light 1 at a predetermined position; a filter member 20 to be excited by the first light 1 from the light source 40 for filtering second light 2 to be emitted from the fluorescent member 10, and for emitting third light 3; and a light collection member 30 disposed between the fluorescent member 10 and the filter member 20 for collecting the second light 2 emitted from the fluorescent member 10, and for making it incident to the filter member 20.

Description

  The present invention relates to 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. Here, by using different phosphors, respective visible lights corresponding to red, green, and blue are emitted.

  By the way, it has been studied to emit light corresponding to red, green, and blue by using the same phosphor and passing light emitted from the phosphor through a filter. In this case, it is conceivable to form a filter layer on the phosphor layer.

  For example, Patent Document 2 discloses providing a bandpass filter layer on a phosphor layer. Many band-pass filter layers generally have an angle dependency.

  FIG. 7 is a schematic cross-sectional view for explaining a problem when a filter layer having an angle dependency is provided on a phosphor layer. As shown in FIG. 7, the phosphor layer 60 contains phosphors 61 dispersedly. A filter layer 62 is provided on the phosphor layer 60. With the excitation light 4 incident on the phosphor layer 60, the phosphor 61 is excited to emit fluorescence 5. This fluorescence 5 is incident on the filter layer 62.

  The fluorescence 5 incident on the filter layer 62 at a small incident angle is filtered by the filter layer 62 and emitted as converted light 6. However, the fluorescence 5 that has entered the filter layer 62 at a large incident angle is not filtered by the filter layer 62, and passes through the filter layer 62 and is emitted as it is. This is caused by the fact that the filter layer 62 has an angle dependency and cannot perform a filtering function for light incident at a large incident angle. For this reason, the utilization efficiency of fluorescent substance fell and there existed a subject that high brightness | luminance could not be obtained as a projector.

JP 2004-341105 A JP 2011-209366 A

  An object of the present invention is to provide a light emitting device for a projector that can increase the utilization efficiency of a phosphor and obtain high luminance.

  The light emitting device for a projector of the present invention is excited by a ring-shaped fluorescent member, a light source for irradiating the fluorescent member rotating in the circumferential direction with a first light at a predetermined position, and the first light from the light source. A filter member for filtering the second light emitted from the fluorescent member to emit the third light, and the second light emitted from the fluorescent member provided between the fluorescent member and the filter member. And a condensing member for condensing and entering the filter member.

  Examples of the filter member include a member having a transparent substrate and a filter layer provided on the transparent substrate. In this case, examples of the filter layer include those composed of a dielectric laminated film.

  An example of the shape of the filter member is a ring shape. In this case, the filter member can be rotated in the circumferential direction in synchronization with the fluorescent member.

  In the present invention, the filter member is, for example, a band pass filter.

  Examples of the fluorescent member include those having a substrate and a phosphor layer provided on the substrate. In this case, examples of the phosphor layer include those having a glass matrix and a phosphor dispersed in the glass matrix.

  According to the present invention, it is possible to increase the utilization efficiency of phosphors and obtain high luminance.

It is a typical side view showing a light emitting device for projectors of one embodiment of the present invention. It is a typical perspective view which shows the light-emitting device for projectors of one Embodiment of this invention. It is a typical side view which shows the light-emitting device for projectors of other embodiment of this invention. It is a perspective view which shows the other example of the condensing member in this invention. It is a perspective view which shows the further another example of the condensing member in this invention. It is a typical front view which shows the other example of the filter member in this invention. It is typical sectional drawing for demonstrating the subject at the time of providing the filter layer which has angle dependence on a fluorescent substance layer.

  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 schematic side view showing a projector light emitting device 50 according to an embodiment of the present invention. FIG. 2 is a schematic perspective view showing a light emitting device 50 for a projector according to an embodiment of the present invention. FIG. 2 shows only the main configuration of the projector light emitting device 50 shown in FIG.

  As shown in FIGS. 1 and 2, the fluorescent member 10 has a ring shape. The fluorescent member 10 includes a ring-shaped 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.

  A rotation shaft 42 of a motor 41 is attached to the center of the ring-shaped fluorescent member 10. Therefore, the ring-shaped fluorescent member 10 is provided so as to rotate in the circumferential direction with the central axis C of the rotation shaft 42 as the rotation center.

  The ring-shaped filter member 20 is attached to the rotating shaft 42. The filter member 20 includes a ring-shaped transparent substrate 21 and a filter layer 22 formed thereon. In the present embodiment, the filter layer 22 is a bandpass filter composed of a dielectric laminated film. Here, the dielectric laminated film is a so-called dielectric multilayer film, and is constituted by a laminated body of a high refractive index film and a low refractive index film. The dielectric laminated film that can be used as a bandpass filter is made of niobium oxide, titanium oxide, lanthanum oxide, tantalum oxide, yttrium oxide, gadolinium oxide, tungsten oxide, hafnium oxide, aluminum oxide, silicon nitride, etc. Examples thereof include a film in which a refractive index film and a low refractive index film composed of silicon oxide or the like are alternately stacked.

  Since the filter member 20 is also attached to the rotation shaft 42, the filter member 20 is provided so as to rotate in the circumferential direction around the central axis C as the rotation center, similarly to the fluorescent member 10. Therefore, the fluorescent member 10 and the filter member 20 rotate in the circumferential direction in synchronization.

  As shown in FIGS. 1 and 2, a light collecting member 30 is provided between the fluorescent member 10 and the filter member 20. In the present embodiment, a convex lens is used as the light collecting member 30. The condensing member 30 is fixedly attached at a predetermined position by an attaching member (not shown). Therefore, the condensing member 30 is fixed at a predetermined position without rotating even when the fluorescent member 10 and the filter member 20 are rotating.

  As shown in FIG. 1, a light source 40 that irradiates the first light 1 is provided. The light source 40 is provided at a position where the first light 1 can enter the fluorescent member 10 through the filter member 20 and the light collecting member 30. Therefore, the light source 40 is provided on the side close to the filter member 20. The first light 1 incident on the phosphor layer 12 of the phosphor member 10 excites the phosphor contained in the phosphor layer 12, and the second light 2 is emitted as fluorescence from the phosphor. A reflective layer is formed on the surface of the substrate 11 in contact with the phosphor layer 12, and the second light 2 emitted from the phosphor is reflected by this reflective layer. Moreover, you may form the whole board | substrate 11 from a reflection member, without providing a reflection layer.

  The second light 2 emitted from the phosphor layer 12 enters the light collecting member 30, is collected by the light collecting member 30, and enters the filter member 20. The second light 2 incident on the filter member 20 is filtered by the filter layer 22 and is emitted as the third light 3. Since the 3rd light 3 is radiate | emitted to the light source 40 side, the light-emitting device 50 for projectors of this embodiment is a reflective light-emitting device.

  Since the first light 1 passes through the transparent substrate 21 and the filter layer 22 of the filter member 20 and enters the fluorescent member 10, the transparent substrate 21 and the filter layer 22 are formed of a material that transmits the first light 1. . Further, since the second light 2 passes through the transparent substrate 21 and enters the filter layer 22, the transparent substrate 21 is formed of a material that also transmits the second light 2. Therefore, “transparent” in the transparent substrate 21 means transparent to the first light 1 and the second light 2.

  In the present embodiment, the second light 2 emitted from the phosphor layer 12 becomes substantially parallel light by the light collecting member 30 and enters the filter member 20. Therefore, the incident angle of the second light 2 incident on the filter layer 22 of the filter member 20 can be reduced. That is, the incident angle to the filter layer 22 can be made closer to the vertical. For this reason, the ratio of the 2nd light 2 which injects with a large incident angle and passes through without being filtered by the filter layer 22 can be reduced. Therefore, according to the present embodiment, the second light 2 emitted from the phosphor layer 12 can be efficiently changed to the third light 3 by the filter layer 22, and the use efficiency of the phosphor can be improved, Brightness can be increased.

  The light source 40 is not particularly limited as long as it emits light that can excite the phosphor contained in the phosphor layer 12 to emit fluorescence. Specific examples of the light source 40 include an LED light source and a laser light source. When a light source that emits blue light (first light 1) is used as the light source 40, for example, the phosphor of the phosphor layer 12 is excited by blue light (first light 1) and yellow light (second light). A phosphor that emits light 2) can be used. Yellow light includes light of green to red wavelengths. In this case, the filter layer 22 can be a magenta filter that filters the green light component contained in the yellow light (second light 2) and transmits the red light (third light 3).

  In the present embodiment, the fluorescent member 10 rotates in the circumferential direction. For this reason, the region that receives the first light 1 from the light source 40 is constantly moving, and even if the first light 1 is received and heated, it is immediately cooled. Therefore, the temperature rise of the fluorescent member 10 can be suppressed. Further, since the filter member 20 is also rotated in the circumferential direction, a temperature rise due to receiving the second light 2 can be suppressed.

  FIG. 3 is a schematic side view showing a light emitting device 51 for a projector according to another embodiment of the present invention. In the present embodiment, the light source 40 is disposed on the side close to the fluorescent member 10. The first light 1 emitted from the light source 40 passes through the substrate 11 of the fluorescent member 10 and enters the phosphor layer 12. The phosphor contained in the phosphor layer 12 is excited by the first light 1 and emits the second light 2. The second light 2 emitted from the phosphor layer 12 becomes substantially parallel light by the light collecting member 30 and enters the filter layer 22 of the filter member 20. The second light 2 incident on the filter layer 22 is filtered by the filter layer 22 and emitted from the filter layer 22 as the third light 3.

  Also in this embodiment, the ratio of the 2nd light 2 which injects with a large incident angle and passes through without being filtered by the filter layer 22 can be reduced. Therefore, the second light 2 emitted from the phosphor layer 12 can be efficiently changed to the third light 3 by the filter layer 22, and the use efficiency of the phosphor can be increased and the brightness of the projector can be increased.

  In the present embodiment, since the first light 1 passes through the substrate 11 and enters the phosphor layer 12, the substrate 11 is a transparent substrate with respect to the first light 1. In the present embodiment, the first light 1 emitted from the light source 40 is emitted to the opposite side to the light source 40 as the third light 3. Therefore, the projector light-emitting device 51 of the present embodiment is a transmissive light-emitting device.

  FIG. 4 is a perspective view showing another example of the light collecting member in the present invention. The condensing member 31 shown in FIG. 4 is a SELFOC (registered trademark) (GRIN) lens. In the condensing member 31, the central portion 31a has a higher refractive index, and the refractive index decreases toward the peripheral portion 31b. Such a SELFOC (registered trademark) (GRIN) lens is disposed between the fluorescent member 10 and the filter member 20 in place of the condensing member 30 shown in FIG. 1 or 3 and used as the condensing member of the present invention. Can do.

  FIG. 5 is a perspective view showing still another example of the light collecting member in the present invention. The condensing member 32 shown in FIG. 5 has a cylindrical shape, and the inner peripheral surface 32a is a reflecting surface. Therefore, the condensing member 32 is a condensing member which condenses by reflection on the inner peripheral surface 32a. Instead of the light collecting member 30 shown in FIG. 1 or 3, the light collecting member 32 by such reflection can be disposed between the fluorescent member 10 and the filter member 20 and used as the light collecting member of the present invention.

  Moreover, although the convex lens is used as the condensing member 30 in FIGS. 1-3, a collimator can also be used.

  In the embodiment shown in FIGS. 1 and 2, the filter member 20 that functions as a single-color bandpass filter has been described as an example, but the present invention is not limited to this.

  FIG. 6 is a schematic front view showing another example of the filter member in the present invention. The filter layer 22 of the filter member shown in FIG. 6 has two sets of a first filter region 22a, a second filter region 22b, and a third filter region 22c. These filter regions are divided and provided in the circumferential direction, as shown in FIG. These filter regions can correspond to, for example, filters that transmit light of red, green, or blue wavelengths. There may be a region where no filter is provided.

  The filter member shown in FIG. 6 has three types of filter regions, but may be a filter member having four or more types of filter regions.

  In the above embodiment, a bandpass filter is described as an example of the filter member 20, but the filter member of the present invention is not limited to the bandpass filter, and a color filter containing a pigment. Other filters may be used. The filter member of the present invention has been described by taking a filter using a dielectric laminated film as an example, but the present invention is not limited to this. The present invention is particularly useful when a filter having an angle dependency is used.

DESCRIPTION OF SYMBOLS 1 ... 1st light 2 ... 2nd light 3 ... 3rd light 4 ... Excitation light 5 ... Fluorescence 6 ... Conversion light 10 ... Fluorescent member 11 ... Substrate 12 ... Phosphor layer 20 ... Filter member 21 ... Transparent substrate 22 ... Filter layer 30 ... Condensing member 31 ... Condensing member 31a ... Central part 31b ... Peripheral part 32 ... Condensing member 32a ... Inner peripheral surface 40 ... Light source 41 ... Motor 42 ... Rotating shaft 50 ... Projection light emitting device 51 ... Projector Light emitting device 60 ... phosphor layer 61 ... phosphor 62 ... filter layer C ... central axis

Claims (8)

A ring-shaped fluorescent member;
A light source for irradiating the fluorescent member rotating in the circumferential direction with a first light at a predetermined position;
A filter member for exciting the first light from the light source and emitting the third light by filtering the second light emitted from the fluorescent member;
A light emitting device for a projector, comprising: a light collecting member provided between the fluorescent member and the filter member for condensing the second light emitted from the fluorescent member and causing the second light to enter the filter member.   The light emitting device for a projector according to claim 1, wherein the filter member includes a transparent substrate and a filter layer provided on the transparent substrate.   The light emitting device for a projector according to claim 2, wherein the filter layer includes a dielectric laminated film.   The light emitting device for a projector according to claim 1, wherein the filter member has a ring shape.   The light emitting device for a projector according to claim 4, wherein the filter member rotates in the circumferential direction in synchronization with the fluorescent member.   The light emitting device for a projector according to claim 1, wherein the filter member is a band pass filter.   The light emitting device for a projector according to any one of claims 1 to 6, wherein the fluorescent member includes a substrate and a phosphor layer provided on the substrate.   The light emitting device for a projector according to claim 7, wherein the phosphor layer includes a glass matrix and a phosphor dispersed in the glass matrix.

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