JP2018105941A - Light emitting wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting wheel in which oscillation upon rotation is suppressed with a weight balance uniform, a temperature rising due to excitation light is suppressed with heat radiation to a formed phosphor layer excellent, and a fall in excitation efficiency of a phosphor and a fall in phosphor life due to deterioration of the phosphor are suppressed.SOLUTION: Each of a plurality of kinds of phosphor layers different in a light emitting color is formed on a metal base to constitute a light emitting wheel of a multiple structure. The metal base 51, in which a red color phosphor layer 54 having a high calorific value upon irradiation of excitation light, and having the widest wavelength region of a spectrum of discharging light is formed, is arranged at the lowermost part to obtain a superior heat radiation effect. An optical cut filter plate 22 is disposed in an optical path of the discharging light, and the wavelength region of the spectrum is partially cut, resulting in improvement in chromatic purity (stimulation purity) of the red light.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light-emitting wheel, and more particularly to a light-emitting wheel used as a light wavelength conversion member in a projector that projects images and text information on a screen, for example.

  Conventionally, as this kind of light-emitting wheel, there is one disclosed in Patent Document 1, for example.

  The disclosed light-emitting wheel (referred to as “optical wheel” in Patent Document 1) 80 is, as shown in FIG. 13, a disk-shaped metal substrate 81 having a part of a window hole and the window. It is comprised with the transparent base material 82 of the circular arc shape which was fixed to the metal base material 81 so that a hole may be plugged, and the part of the metal base material 81 is green fluorescence on the mirror surface which performed the mirror surface process. The body layer is laid in a partial annular shape with a predetermined width to form a green fluorescent light emitting region 83, and the transparent substrate is subjected to a diffusion treatment to form a partial annular shape on the same circle as the green phosphor layer of the metal substrate. The diffusion transmission region 84 is formed in parallel.

  As a result, while the emitted light (blue laser light) from the excitation light irradiation device is irradiated on the green phosphor layer of the rotating optical wheel, the irradiation light excites the green phosphor and emits it from the green phosphor. While the emitted green fluorescence is directed in the opposite direction along the same optical path as the irradiation light by the mirror surface and is irradiated on the transparent substrate, the blue diffused light is transmitted in the transmission direction by spreading on the transparent substrate.

  Then, the three wavelength region lights of the green wavelength region light composed of green fluorescence from the optical wheel, the blue wavelength region light composed of blue diffused light, and the red wavelength region light emitted from the red light source device are respectively guided by the light guide optical system. After the optical axis direction is positioned on the same optical axis, the light source side optical system guides it to the projection side optical system and projects it as a projector image.

Japanese Patent Laid-Open No. 2006-57375

  By the way, in the optical wheel having the above-described configuration, the green wavelength region light composed of green fluorescence emitted from the green phosphor excited by the irradiation light has a wider wavelength region than other blue wavelength region light and red wavelength region light. It has optical properties with low color purity (stimulus purity). Therefore, in additive color mixing with light in other wavelength regions, the range of colors (hue) that can be expressed is narrowed, resulting in a projector with poor color reproducibility.

  Also, since a transparent base material is separately attached to a part of a disk-shaped metal base material, the weight balance in the disk is not uniform, and vibration occurs when the optical wheel rotates, making the optical system unstable. As a result, a clear image may not be obtained.

  Furthermore, since the green phosphor layer is irradiated with laser light, if the heat radiation is insufficient, the excitation efficiency decreases as the temperature of the phosphor increases, and the amount of fluorescence decreases. The excitation efficiency decreases. As a result, the color to be expressed may change because the color mixture ratio changes in additive color mixing with light in other wavelength regions.

  Therefore, the present invention was devised in view of the above problems, and the object of the present invention is to provide a uniform weight balance, suppress vibration during rotation, and excite heat radiation to the laid phosphor layer. An object of the present invention is to provide an optical wheel (light-emitting wheel) in which a temperature rise due to light is suppressed, a decrease in excitation efficiency of the phosphor and a decrease in phosphor lifetime due to the deterioration of the phosphor are suppressed.

  In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention is a light-emitting wheel having a multiple structure composed of a plurality of constituent members, and is on the same circumference centering on the rotation axis in plan view. A plurality of types of phosphor layers having different fluorescent colors that are divided and arranged at a predetermined ratio in the circumferential direction, and an optical path of emitted light from at least one of the plurality of types of phosphor layers And a wavelength cut filter that is arranged and cuts a part of the wavelength region of the emitted light.

  The invention described in claim 2 of the present invention is that, in claim 1, a diffusion transmission member that diffuses and transmits excitation light constitutes one of the divided arrangements in a plan view, and the diffusion transmission member includes It has the same shape and dimension as the wavelength cut filter and is disposed at a symmetrical position on the reflection side facing the wavelength cut filter across the rotation axis.

  Further, in the invention described in claim 3 of the present invention, in any one of claim 1 or claim 2, the plurality of types of phosphor layers are all formed on a base, and at least one of them is formed. The base on which the phosphor layer is formed is arranged on the side opposite to the light receiving side of the excitation light.

  The invention described in claim 4 of the present invention is characterized in that, in claim 3, the base on which the plurality of types of phosphor layers are formed is formed of a metal member. is there.

  The invention described in claim 5 of the present invention is characterized in that in any one of claims 1 to 4, the wavelength cut filter and the diffuse transmission member are both formed of a glass member. To do.

  According to the present invention, a multiple structure including a plurality of types of phosphor layers having different fluorescent colors that are divided and arranged at a predetermined ratio in the circumferential direction on the same circumference around the rotation axis in plan view In the light emitting wheel, a wavelength cut filter for cutting a part of the wavelength region of the emitted light is provided on the optical path of the emitted light from at least one kind of the phosphor layers. Thereby, the wavelength range of emitted light is partially cut, and light with high color purity (stimulus purity) can be obtained.

  Further, the base on which at least one phosphor layer of the plurality of types of phosphor layers was formed was disposed on the side opposite to the excitation light receiving side. As a result, heat generated from the phosphor layer during irradiation of the irradiation light is efficiently dissipated into the air through the entire back surface of the base, and the temperature rise of the phosphor layer is effectively suppressed.

  Furthermore, the diffuse transmission member and the wavelength cut filter having the same shape and the same weight are arranged at symmetrical positions on the reflection side facing each other across the rotation axis. Thereby, the center of gravity position is located in the vicinity of the center (rotation center), and it is possible to obtain outgoing light with less blur due to good rotation balance. Moreover, the lifetime reduction of a motor can be suppressed by favorable rotation balance.

It is a disassembled perspective view of the light emission wheel which concerns on 1st Embodiment. It is a top view of the light emission wheel concerning a 1st embodiment. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is explanatory drawing which shows the spectrum cut area | region of an optical cut filter board. It is explanatory drawing which shows the fluorescence area | region of a light emission wheel, and the irradiation locus | trajectory of excitation light. It is optical path explanatory drawing using the AA cross section of a light emission wheel. It is optical path explanatory drawing using the BB cross section of the light emission wheel. It is a timing chart of the emitted light from a light emission wheel. It is explanatory drawing which shows the relationship between the optical path length ratio of the irradiation light in each color fluorescent substance layer, and light emission time ratio. It is a disassembled perspective view of the light emission wheel which concerns on 2nd Embodiment. It is optical path explanatory drawing which shows the difference with 1st Embodiment in 2nd Embodiment. It is explanatory drawing of a prior art example.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 to 12 (the same reference numerals are given to the same portions). The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. Unless stated to the effect, the present invention is not limited to these embodiments.

  1 is an exploded perspective view of a light emitting wheel according to a first embodiment of the present invention, FIG. 2 is a plan view, FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, and FIG. is there.

  The light emitting wheel according to the first embodiment has a multiple structure composed of a plurality of constituent members, and has a disk shape having a rotation shaft insertion hole into which the rotation shaft is inserted at the center position.

  In the plan view of the light-emitting wheel, a phosphor layer containing a plurality of types of phosphors having different fluorescent colors is formed on the same circumference centered on the rotation shaft insertion hole. It is arranged for each of a plurality of divided areas obtained by dividing the entire circumference 360 ° at a predetermined ratio.

  When each phosphor layer of the light-emitting wheel that is rotated to the irradiation position of the light emitted from the light source (excitation light) is positioned, fluorescence is emitted from each phosphor layer excited by the excitation light, and the fluorescence is emitted from the light-emitting wheel. It is emitted as outgoing light. The excitation light is also used as the emitted light from the light emitting wheel.

  Next, the configuration of the light emitting wheel will be described in detail.

  The light-emitting wheel 1 has a five-layer structure composed of five constituent members, a first constituent member 10, a second constituent member 20, a third constituent member 30, a fourth constituent member 40, and a fifth constituent member 50 in order from the top. It has become.

  The first component 10 is composed of a base plate and a phosphor layer, and the base plate 11 includes a rotary shaft insertion hole 12 positioned at the center with respect to the disc-shaped metal plate, and a rotary shaft. Two cut-out portions (first cut-out portion 13 and second cut-out portion 14) that are cut out in fan-like shapes that open toward the outside at opposite symmetrical positions on both sides across the fitting hole 12, and orthogonal to the two cut-out portions Two fan-shaped extending plate portions (first extending plate portion 15 and second extending plate portion 16) that open outward at symmetrical positions on both sides facing each other across the rotation shaft insertion hole 12 in the direction of have.

  The phosphor layer is predetermined on the outer peripheral edge portion of the first extending plate portion 15 and the outer peripheral edge portion of the second extending plate portion 16 of the base plate 11 along respective arc-shaped outer peripheral circles (edges) 15a and 16a. In the present embodiment, the phosphor layer formed on the outer peripheral edge of the first extension plate portion 15 is excited by excitation light and emits yellow fluorescence. It is the yellow fluorescent substance layer 17 containing yellow fluorescent substance, and the fluorescent substance layer formed in the outer peripheral part of the 2nd extending plate part 16 contained the green fluorescent substance which is excited by excitation light and discharge | releases green fluorescence. This is the green phosphor layer 18.

  The surface of the base plate 11 on which the yellow phosphor layer 17 and the green phosphor layer 18 are formed is subjected to vapor deposition or plating with a reflective metal such as aluminum to form a metal reflective film. The surface is a specular reflection surface.

  The metal reflection film may be formed on the entire surface of the base plate 11, or may be partially formed only in the lower regions of the yellow phosphor layer 17 and the green phosphor layer 18. In other words, the yellow phosphor layer 17 and the green phosphor layer 18 are formed on the specular reflection surface.

The second component member 20 is located below the first component member 10, that is, on the opposite side of the first component member 10 from the side on which the yellow phosphor layer 17 and the green phosphor layer 18 are formed. The second component member 20 is composed of two optical function plates, one of which is a diffuse transmission plate 21 having a configuration in which a light diffusing agent such as SiO ₂ or Al ₂ O ₃ is mixed in glass. The other one is a light cut filter plate 22 having a structure in which, for example, a substance that absorbs light in a predetermined wavelength region is mixed in glass.

  In particular, as shown in FIG. 5, the light cut filter plate 22 has a spectrum of red fluorescence emitted from a red phosphor layer 54 (described later) excited by excitation light from the longest wavelength side of the spectrum region of excitation light. It has an optical characteristic of cutting light in the wavelength region up to the vicinity of the peak wavelength on the short wavelength side of the region.

  As a result, the light transmitted through the light cut filter plate 22 is narrowed in the wavelength region (in other words, the spectrum half width) with respect to the red fluorescence from the red phosphor layer 54, and the color purity (in other words, the excitation purity) of the red fluorescence is reduced. Enhanced red light is obtained.

  The diffuse transmission plate 21 and the light cut filter plate 22 constituting the second component member 20 have the same shape and the same weight, and have an arc shape with a predetermined width and length. The diffusion transmission plate 21 is located at a position that covers the entire cutout portion 13 from below, and similarly, the light cut filter plate 22 is located at a position that covers the entire second cutout portion 14 of the base plate 11 from below. Further, the diffuse transmission plate 21 and the light cut filter plate 22 are positioned at symmetrical positions on both sides of the base plate 11 across the rotation shaft insertion hole 12, and the outer circumference (edge) of the diffusion transmission plate 21. The outer circumference (edge) 22a of the optical filter plate 21a and the outer circumference circle (edge) 15a of the first extension 15 of the base plate 11 and the outer circumference (edge) 16a of the second extension 16 are the same circumference. Located on the top.

  The third component 30 is positioned below the diffuse transmission plate 21 and the light cut filter plate 22 constituting the second component 20, that is, on the opposite side of the diffuse transmission plate 21 and the light cut filter plate 22 from the first component 10. doing.

  The third component 30 has a predetermined width and length at a rotational shaft insertion hole 31 located at the center position with respect to the disk-shaped metal plate, and symmetrical positions on both sides opposed to each other across the rotation shaft insertion hole 31. It has two arc-shaped window holes (first window hole 32 and second window hole 33).

  The first window hole 32 is positioned below each of the first cutout portion 13 and the diffusion transmission plate 21 of the base plate 11 positioned above, and has a shape and dimension that includes the entire first cutout portion 13 in plan view. The width and length of the diffuse transmission plate 21 are small.

  The second window hole 33 is located below each of the second cutout portion 14 and the light cut filter plate 22 of the base plate 11 located above, and has a shape that includes the entire second cutout portion 14 in plan view. In addition to having dimensions, the width and length of the light cut filter plate 22 are small.

  Thereby, the diffuse transmission plate 21 and the light cut filter plate 22 constituting the second component member 20 are sandwiched between the base plate 11 and the third component member 30 constituting the first component member 10.

  The fourth component member 40 is located below the third component member 30, that is, on the opposite side of the diffusion transmission plate 21 and the light cut filter plate 22 that constitute the second component member 20 of the third component member 30.

  The fourth component member 40 has a metal flat plate shape, and the portion of the window frame 32 a along the outer edge portion of the first window hole 32 and the outer edge portion of the second window hole 33 with respect to the third component member 30 located above. The shape (the 1st cutting part 42 and the 2nd cutting part 43) which cut off the part of the window frame 33a in alignment with. In other words, it has a shape extending substantially in a band shape in a direction orthogonal to the first window hole 32 and the second window hole 33 of the third component member 30 including the rotation shaft insertion hole 41.

  The fifth component member 50 is located below the fourth component member 40, that is, on the opposite side of the fourth component member 40 from the third component member 30.

  The fifth component member 50 is composed of a base plate and a phosphor layer in the same manner as the first component member 10, and the base plate 51 is a rotary shaft inserted at a central position with respect to the disc-shaped metal plate. A fitting hole 52 and an arcuate window hole 53 having a predetermined width and length are provided, and the opposite side of the window hole 53 across the rotation shaft insertion hole 52 is cut in a substantially radial direction along the window hole 53. The cut-out portion 55 has a different shape.

  The window hole 53 of the fifth component member 50 is positioned below the second window hole 33 of the third component member 30 located above, and the portion of the window frame 53 a along the outer edge of the window hole 53 is the second window hole 33. The window frame 33a is formed to be wider than the portion of the window frame 33a along the outer edge of the window frame 33a, and the length of the window frame 33a is longer than that of the window frame 33a.

  The phosphor layer is formed with a predetermined uniform thickness on the fourth component member 40 side of the portion of the window frame 53a. In this embodiment, a red phosphor that is excited by excitation light and emits red fluorescence is used. The red phosphor layer 54 is contained.

  The third component member 30 and the fifth component member 50 are overlapped via the fourth component member 40, and the thickness of the red phosphor layer 54 is formed thinner than the thickness of the fourth component member 40. Therefore, a gap 60 is secured between the upper surface 54 a of the red phosphor layer 54 and the lower surface 30 a of the third component member 30. Thus, the fourth component member 40 has a function as a spacer.

  The surface of the base plate 51 on which the red phosphor layer 54 is formed is subjected to vapor deposition or plating with a reflective metal such as aluminum to form a metal reflective film, and the surface is a mirror surface It is a reflective surface.

  The metal reflection film may be formed on the entire surface of the base plate 51 or may be partially formed only in the lower region of the red phosphor layer 54. In other words, the red phosphor layer 54 is formed on the specular reflection surface.

  Next, the optical function of the light-emitting wheel having the five-layer structure formed by superimposing the above-described five constituent members will be described below with reference to FIGS.

  The light emitted from the light source is collected through a condensing optical system (not shown) and irradiated toward a predetermined fixed position, and an irradiation locus (as shown in FIG. Irradiated light from above (on the side of the yellow phosphor layer 17 and the green phosphor layer 18 constituting the first component 10) along C).

While the irradiation position of the irradiation light (blue laser light in the present embodiment) L is on the yellow phosphor layer 17 in the yellow fluorescence region (Y) in plan view, the yellow contained in the yellow phosphor layer 17 The phosphor is excited by the irradiation light L and emits yellow fluorescence. This yellow fluorescence is reflected by the specular reflection surface of the first extending plate portion 15 of the base plate 11 on which the yellow phosphor layer 17 is formed, immediately below the yellow phosphor layer 17, and the irradiation light L of the light emitting wheel 1. toward the yellow light L _Y in the direction of the irradiation direction opposite (upper) (see FIG. 7).

  Next, when the light emitting wheel 1 rotates and the position of the irradiation light L moves on the red phosphor layer 54 in the red fluorescent region (R) in plan view, the irradiation position of the irradiation light L is on the red phosphor layer 54. The second component member passes through the second notch portion 14 of the base plate 11 constituting the first component member 10 located above the red phosphor layer 54 constituting the fifth component member 50. The light cut filter plate 22 constituting 20 is irradiated.

  Since the light cut filter plate 22 has the spectral characteristics that transmit the blue light of the irradiation light L as described above, the light cut filter plate 22 passes through the light cut filter plate 22 as it is, and the third component member 30 located below the third cutout plate 30 has a spectral characteristic. The second phosphor hole 54 and the second cutout portion 43 of the fourth component member 40 located below the second hole 33 are irradiated to the red phosphor layer 54 constituting the fifth component member 50 located below and irradiated with the light. The red phosphor contained in the red phosphor layer 54 is excited by L and emits red fluorescence.

This red fluorescence is reflected by the mirror reflection surface immediately below the red phosphor layer 54 of the window frame 53a of the fifth component 50 where the red phosphor layer 54 is formed, and is opposite to the irradiation direction of the irradiation light L. direction (upward) toward the red light _{L R.} And the optical cut filter board which comprises the 2nd cutout part 43 of the 4th structural member 40 located above, and the 2nd window hole 33 of the 3rd structural member 30 located above it, and comprises the 2nd structural member 20 22 is irradiated.

  At this time, the red light applied to the light cut filter plate 22 has a wide wavelength region with respect to the yellow light from the yellow phosphor layer 17, the green light from the green phosphor layer 18, and the blue light of the laser beam. The purity is low. Therefore, the red light applied to the light cut filter plate 22 is transmitted through the light cut filter plate 22, so that the rising of the short wavelength side of the spectral region of the red light is from the wavelength to the short wavelength side as described above. Red light having a wavelength region in which the wavelength region up to the vicinity of the peak wavelength is cut to narrow the spectral half width is generated.

  As a result, red light having substantially the same color purity as that of yellow light, green light, and blue light can be obtained.

And the red light which permeate | transmitted the light cut filter board 22 passes the 2nd notch part 14 of the base plate 11 which comprises the 1st structural member 10 located above the light cut filter board 22, and the light emission wheel 1 The red light _LRR travels in the direction (upward) opposite to the irradiation direction of the irradiation light L (see FIG. 8).

Next, when the light emitting wheel 1 rotates and the position of the irradiation light L moves to the green phosphor layer 18 in the green fluorescent region (G) in plan view, the irradiation position of the irradiation light L is on the green phosphor layer 18. During this period, the green phosphor contained in the green phosphor layer 18 is excited by the irradiation light L and emits green fluorescence. The green fluorescence is reflected by the specular reflection surface of the first extending plate portion 15 of the base plate 11 on which the green phosphor layer 18 is formed, immediately below the green phosphor layer 18, and the irradiation light L of the light emitting wheel 1. towards the green light L _G opposite the direction to the irradiation direction of the (upper) (see FIG. 7).

Next, when the light emitting wheel 1 rotates and the position of the irradiation light L moves onto the diffusion transmission plate 21 in the diffusion transmission region (B) in plan view, the irradiation position of the irradiation light L is on the diffusion transmission plate 21. The space is irradiated to the diffuse transmission plate 21 that constitutes the second component member 20 through the first notch 13 of the base plate 11 that constitutes the first component member 10 that is positioned above, towards the blue of the diffused light L _B in the transmission to radiation in the same direction side of the irradiation light L (lower) a.

  Further, it passes through the first window hole 32 of the third component member 30 located below, the first cutout portion 42 of the fourth component member 40 located below it, and the cutout portion 55 of the fifth component member 50 sequentially. Heading below the light-emitting wheel 1 (see FIG. 8).

Figure 9 is a timing chart showing the yellow light L _Y which irradiation light emitted from the light-emitting wheel 1 which has been _irradiated, the red light L _RR, the emission timing of the green light L _G and the blue light L _B.

A light-emitting wheel 1 is rotated from the light-emitting wheel 1, is emitted in a time-division in order of yellow light L _Y, the red light L _RR, the green light L _G and the blue light L _B. In particular, in the light-emitting wheel 1 rotating at a constant speed, the period of one rotation is T, the emission time (light emission time) of the yellow light L _Y is T _Y , the emission time (light emission time) of the red light L _RR is T _RR , and the green light L _G emission time of (light emission time) _{T G,} emission time of the blue light _{L B} (the emission time) and _{T B,} the relation of _{T = T Y + T RR +} T G + T B.

Further, as shown in FIG. 10, the optical path length of the irradiation light when the light-emitting wheel 1 makes one rotation is D, the optical path length on the yellow phosphor layer 17 is D _Y , and the optical path length on the red phosphor layer 54 is D _RR, the optical path length _{D G} on the green phosphor layer 18, the optical path length of the diffuse transmission plate 21 and _{D B,} the relation of _{D = D Y + D RR +} D G + D B. Also, the relationship between the optical path length and the emission time of each color light (light emission _{time), D Y: D RR:} D G: D B = T Y: T RR: T G: a _{T B.} Therefore, when it is desired to change the ratio of the lighting time of each color light appropriately, it is possible to set the ratio of the optical path length of each color light correspondingly.

  In addition, the setting of the ratio of the optical path length of each color light is performed by setting the ratio of the lengths of the yellow fluorescent region (Y), the red fluorescent region (R), the green fluorescent region (G), and the diffuse transmission region (B) of the light emitting wheel 1. It becomes possible by setting.

  For example, in a projector, each color light emitted from the light emitting wheel 1 in a time division manner is controlled to travel in the same direction on the same optical path by a light guide optical system (not shown) at the subsequent stage, and each color light is respectively transmitted at the subsequent stage. The image and character information obtained by irradiation with controlled timing are projected on the screen.

  By the way, the above-mentioned light emitting wheel 1 emits light of three colors, yellow light, red light, and green light, in the same direction, and only blue light is emitted in the opposite direction. Similarly to the three colors of light, the light can be emitted in the same direction.

  In order to realize this, as the second embodiment, the first component member 10, the second component member 20, the third component member 30, the fourth component member 40, and the fifth component member 50 constituting the light emitting wheel 1 are used. Of these five components, only the shape of the fifth component 50 may be partially changed.

  Specifically, as shown in the exploded perspective view of FIG. 11, the cutout portion 55 formed on the fifth component 50 and through which the blue light passes is eliminated, and this portion is replaced with a flat plate portion 56. The base plate 51 is provided, and a metal reflection film is formed on the upper surface 56a of the flat plate portion 56 so that the surface is a specular reflection surface.

Thereby, as shown in FIG. 12, when the light emitting wheel 1 rotates and the position of the irradiation light L moves on the diffusion transmission plate 21 constituting the second component member 20 in the diffusion transmission region (B) in plan view, While the irradiation position of the irradiation light L is on the diffusing and transmitting plate 21, it passes through the first notch 13 of the base plate 11 constituting the first component member 10 located above and passes through the second component member 20. is shone on to the diffuse transmission plate 21 constituting toward a blue diffused light L _B in the irradiation direction in the same direction side of the irradiation light L is transmitted through the diffusion transmission plate 21 (downward).

  Further, the first window hole 32 of the third component member 30 positioned below, the first cutout portion 42 of the fourth component member 40 positioned below it, and the flat plate portion 56 of the fifth component member 50 positioned below it. Is irradiated.

Diffused light L _B of the blue emitted to the flat plate portion 56 of the fifth component 50, the reflected light is reflected toward the opposite direction to the irradiation direction of the irradiation light L in specular surfaces of the upper surface 56a of the flat plate portion 56 L _B is emitted from the same light emitting wheel 1 and the other three colors of light through the same optical path as the irradiation light L upward.

In this case, the incident light L is transmitted back and forth twice through the diffuse transmission plate 21 constituting the second component member 20 until it is reflected by the flat plate portion 56 of the fifth component member 50 and emitted from the light emitting wheel 1. Therefore, light emitted blue diffused light L _B from the light-emitting wheel 1 diffusivity is high for blue diffuses light L _B of the first embodiment.

  Therefore, in order to make the blue emission from the light emitting wheel 1 of the second embodiment have the same degree of diffusion as the blue emission light of the first embodiment, the light in the diffuse transmission plate 21 of the second embodiment. It is necessary to reduce the concentration of the diffusing agent to about one half of the concentration of the light diffusing agent in the diffusion transmission plate 21 of the first embodiment.

  In both the first embodiment and the second embodiment, the outer peripheral circle (edge) 15a of the first extension 15 and the second extension 16 of the base plate 11 constituting the first component member 10 are the same. An outer circumference circle (edge) 16 a, an outer circumference circle (edge) 21 a of the diffusion transmission plate 21 constituting the second component member 20, an outer circumference circle (edge) 22 a of the light cut filter plate 22, and an outer circumference circle of the third component member 30. (Rim) 30b, the outer circumference circle (edge) 40a of the fourth component member 40, and the outer circumference circle (edge) 51a of the base plate 51 constituting the fifth component member 50 are the respective rotary shaft insertion holes 12. , 31, 41, and 52 are located on the same circumference.

  By the way, the light emitting wheel 1 described above is divided into four regions in the circumferential direction so that light of different colors (hues) is emitted from each region in a time division manner. However, the present invention is not limited to this, and by appropriately setting the number of divisions of the region, it is possible to obtain light of a corresponding color (hue).

  Further, in both the first embodiment and the second embodiment, blue laser light is used as excitation light of the phosphor included in each phosphor layer, and the blue laser light is also used as emission light of the light emitting wheel. However, an ultraviolet laser beam can be used instead of the blue laser beam as the excitation light of the phosphor. In that case, all the emitted light from the light emitting wheel is obtained by fluorescence from the phosphor layer formed on the light emitting wheel.

  As described above, in the light emitting wheel of the present invention, since any phosphor layer is formed on the metal plate, the heat generated from the phosphor layer when irradiated with the irradiation light is dissipated by the metal plate, and the temperature of the phosphor layer. The top is suppressed. As a result, a decrease in excitation efficiency due to heat of the phosphor can be suppressed, and a sufficient amount of fluorescence can be ensured. At the same time, by suppressing the temperature rise of the phosphor layer, deterioration of the phosphor can be suppressed and the lifetime of the phosphor can be extended.

  In particular, a metal plate on which a red phosphor layer having a large calorific value is formed is disposed at the bottom of the quintuple structure, and the back surface is in contact with the atmosphere (air). Therefore, the heat of the red phosphor layer is efficiently dissipated into the air through the entire back surface of the metal plate, and the temperature rise of the red phosphor layer is effectively suppressed.

  The red fluorescence from the red phosphor layer has a wider wavelength range than the green fluorescence from the green phosphor layer, the yellow fluorescence from the yellow phosphor layer, and the blue laser light. Therefore, by transmitting the red fluorescence from the red phosphor layer through the light cut filter plate, it is possible to generate red light having a wavelength region in which the wavelength region is partially cut to narrow the spectral half width.

  As a result, red light having substantially the same wavelength purity (stimulus purity) is obtained with a wavelength region (spectrum half-value width) substantially equal to that of green fluorescence, yellow fluorescence, and blue laser light. As a result, the range of colors (hue) that can be expressed can be expanded.

  Furthermore, four constituent members among the five constituent members of the disc-shaped light emitting wheel having a five-layer structure are formed symmetrically with respect to the center. Among them, in particular, since the heavy glass members are arranged symmetrically, the center of gravity position is located in the vicinity of the center (rotation center), and it is possible to obtain outgoing light with less blur due to a good rotation balance.

DESCRIPTION OF SYMBOLS 1 ... Light emission wheel 10 ... 1st structural member 11 ... Base plate 12 ... Rotating shaft insertion hole 13 ... 1st notch part 14 ... 2nd notch part 15 ... 1st extension plate part 15a ... Outer periphery circle | round | yen (edge)
16 ... 2nd extended plate part 16a ... Perimeter circle (edge)
17 ... Yellow phosphor layer 18 ... Green phosphor layer 20 ... Second component 21 ... Diffusion plate 21a ... Peripheral circle (edge)
22 ... Optical cut filter plate 22a ... Peripheral circle (edge)
30 ... 3rd component 30a ... Lower surface 30b ... Perimeter circle (edge)
31 ... Rotating shaft insertion hole 32 ... 1st window hole 32a ... Window frame 33 ... 2nd window hole 33a ... Window frame 40 ... 4th structural member 40a ... Peripheral circle (edge)
41 ... Rotating shaft insertion hole 42 ... 1st cutting part 43 ... 2nd cutting part 50 ... 5th structural member 51 ... Base plate 51a ... Peripheral circle (edge)
52 ... Rotating shaft insertion hole 53 ... Window hole 53a ... Window frame 54 ... Red phosphor layer 54a ... Upper surface 55 ... Cutout portion 56 ... Flat plate portion 56a ... Upper surface 60 ... Gap

Claims (5)

A light emitting wheel having a multiple structure composed of a plurality of components,
A plurality of types of phosphor layers having different fluorescent colors and arranged in a predetermined ratio of length in the circumferential direction on the same circumference around the rotation axis in plan view;
A wavelength cut filter disposed on an optical path of emitted light from at least one of the plurality of phosphor layers and cutting a part of a wavelength region of the emitted light. Luminous wheel.   A diffuse transmission member that diffuses and transmits the excitation light constitutes one of the divided arrangements in plan view, and the diffusion transmission member has the same shape and dimension as the wavelength cut filter, and the wavelength cut filter with the rotation axis interposed therebetween. The light-emitting wheel according to claim 1, wherein the light-emitting wheel is disposed at a symmetrical position on the reflection side opposite to.   The plurality of types of phosphor layers are all formed on a base, and the base on which at least one type of phosphor layer is formed is disposed on the side opposite to the light receiving side of the excitation light. The light-emitting wheel according to claim 1, wherein the light-emitting wheel is characterized by.   4. The light emitting wheel according to claim 3, wherein the base on which the plurality of types of phosphor layers are formed is formed of a metal member.   5. The light emitting wheel according to claim 2, wherein each of the wavelength cut filter and the diffuse transmission member is formed of a glass member.

Images