JP6094866B2 - Illumination optics - Google Patents

Description

The present invention relates to an illumination optical system using an array light source that emits a laser beam in a blue band, and more particularly to an illumination optical system used as a light source of an electronic device such as a projector or a lighting device.

It is known that a blue laser light emitter is used as a light source for a light source unit of a projector (Patent Document 1). This light source unit includes a blue laser light emitter, a phosphor wheel, and a plurality of reflection mirrors and dichroic mirrors. The phosphor wheel has a disk shape rotated by a motor, and the phosphor wheel has a transmitting portion that transmits light in the blue band and a phosphor that emits light in the blue band and emits light in the red band and green band. Each layer is formed.

Japanese Patent No. 471154

Since the light source unit shown in Patent Document 1 has a configuration in which the phosphor wheel transmits light in the blue band, there are restrictions on the layout of the optical system and the like, and the light source unit is necessarily downsized and space-saving. It could not be said that it was suitable for.

Therefore, an object of the present invention is to provide an illumination optical system capable of reducing the number of optical components, saving space, reducing weight, and reducing cost, and an electronic device using the same.
Another object of the present invention is to provide a rotating body capable of effectively preventing color mixing of light in the blue band and light in the red band and the green band, and an illumination optical system using the rotating body.

The rotating body according to the present invention is for injecting light into a blue band to generate light in at least a blue band, a red band, and a green band, and the rotating body has a first surface and the first surface. It has a second surface facing the surface, and the first surface has a reflection region that reflects light in at least the blue band and a reflection region that transmits light in the blue band and reflects light in at least the red band and the green band. A dichroic region is formed, and on the second surface, a first phosphor region that emits light in the red band based on the light in the blue band transmitted through the dichroic region and a first phosphor region that emits light in the green band and light in the green band are emitted. Two phosphor regions are formed. In a preferred embodiment, the reflective region on the first surface is composed of a reflective mirror, a reflective layer, a reflective member, a reflective filter, and the like. Further, the dichroic region formed on the first surface is composed of a dichroic mirror and a dichroic filter. In a more preferred embodiment, a plurality of sets of the first and second phosphor regions may be formed in the radial direction of the second surface. More preferably, the rotating body includes a transparent substrate having a first surface and a second surface facing the first surface, and the reflection region and the dichroic region are the first surface of the transparent substrate. Formed on top, the first and second phosphor regions are formed on the second surface of the transparent substrate.

The illumination optical system according to the present invention is arranged between the rotating body described above, a light source that emits light in the blue band, and the rotating body and the light source, and the light in the blue band from the light source is used as the first light. The rotating body has a first optical system that focuses on an axis and a second optical axis that is shifted from the first optical axis, and collects light in the blue band that is focused by the first optical system. It has a second optical system that concentrates light on the surface. In a preferred embodiment, the light focused by the first optical system is incident on one half of the lens of the second optical system. The illumination optical system can further include a condenser lens that collects the red band and green band light emitted from the rotating body. The illumination optical system can further include a dividing member that divides the light in the blue band from the light source into n sets (n is an integer of 2 or more). The illumination optical system can further include a dichroic mirror that reflects the light collected by the condenser lens, and the dichroic mirror reflects light in the blue band and transmits light in at least the red band and the green band. To do. The illumination optical system can further include a dichroic mirror that reflects the light collected by the condenser lens, and the dichroic mirror transmits light in the blue band and reflects light in at least the red band and the green band. To do.

According to the present invention, it is possible to provide an illumination optical system in which the number of parts is reduced, and the size, weight, and cost are reduced, and an electronic device using the same. Further, by using the rotating body of the present invention, it is possible to effectively prevent the light in the blue band from being mixed with the light in the red band and the green band.

It is a figure explaining the principle of the illumination optical system which concerns on 1st Example of this invention. It is schematic cross-sectional view which shows the structural example of the array light source shown in FIG. FIG. 3A is a plan view of the incident surface side of the phosphor wheel of this embodiment, FIG. 3B is a plan view of the emitting surface side of the large fluorescent wheel, and FIG. 3C is FIG. 3 (C). B) is a sectional view taken along line XX. FIG. 4A is a diagram schematically illustrating how the phosphor wheel according to the present embodiment generates light in the blue band, and FIG. 4B is a diagram showing the red band / by the phosphor wheel according to the present embodiment. It is a figure which shows how the light of a green band is generated schematically. It is a figure explaining the principle of the illumination optical system which concerns on the 2nd Example of this invention. It is a figure explaining the principle of the illumination optical system which concerns on 3rd Example of this invention. It is a graph which shows the relationship between the emission change efficiency of a phosphor, and the irradiation energy density. It is a figure which shows the example which synthesizes the light of R / G / B in the illumination optical system which concerns on Example of this invention.

Next, an embodiment of the present invention will be described in detail with reference to the drawings. In a preferred embodiment of the present invention, the illumination optical system utilizes a blue laser element or an array light source in which a blue light emitting diode is arrayed as a semiconductor light emitting element that emits blue light having a short wavelength. The illumination optical system uses light in the blue band, and the optical axis is shifted in order to generate light in the red band, green band, or yellow band having a longer wavelength, and wavelength conversion. A rotating body in which a phosphor region for the above is formed is used. It should be noted that the scale of the drawings is emphasized for the sake of clarity of the features of the invention and is not necessarily the same as the scale of the actual device.

FIG. 1 is a diagram illustrating a basic principle of an illumination optical system according to a first embodiment of the present invention. In the following description, red band light, green band light, and blue band light may be abbreviated as R, G, and B for convenience.

The illumination optical system 10 of this embodiment includes an array light source 20 that emits a laser beam Lb in the blue band as excitation light, front group lenses L1 and L2 that collect the laser light Lb from the array light source 20, and a front group. A rear group lens L3 that concentrates the laser light Lb focused by the lenses L1 and L2 on the phosphor wheel 30, and a region that selectively reflects and transmits the laser light Lb in the blue band are included and transmitted. A disk-shaped phosphor wheel 30 having a phosphor region that is excited by a blue band laser beam Lb and emits a red band light Lr and a green band light Lb, and a phosphor coupled to the central axis of the phosphor wheel 30. The motor 40 that rotates the wheel 30, the reflection mirror 50 that reflects the blue band laser light Lb reflected on the incident surface side of the phosphor wheel 30 in a certain direction, and the emission surface side of the phosphor wheel 30 are emitted. A condenser lens L4 that collects light Lr in the red band and light Lg in the green band, and a reflection mirror 60 that reflects light Lr / Lb in the red band and green band focused by the condenser lens L4 in a certain direction. Consists of including.

The array light source 20 includes a plurality of semiconductor laser elements (or blue light emitting diodes) that emit laser light in the blue band in an array. The semiconductor laser elements are arranged one-dimensionally or two-dimensionally, and by driving a plurality of semiconductor laser elements at the same time, laser light is emitted from each semiconductor laser element all at once.

FIG. 2 is a schematic cross-sectional view showing a configuration example of an array light source. As shown in the figure, a substrate on which a plurality of semiconductor laser elements are mounted is supported by a support member 22 made of a metal material having high thermal conductivity, for example, a material such as aluminum. Further, a lens 24 that collimates the laser light emitted from each semiconductor laser element is attached to the surface of the support member 22. Further, a reflection mirror 26 is arranged on the side facing the support member 22, and the reflection mirror 26 reflects the light in the blue band emitted from each semiconductor laser element in a certain direction to generate a laser beam bundle Lb.

The front group lens L1 is composed of, for example, a plano-convex lens, the front group lens L2 is composed of, for example, a concave lens, and the front group lenses L1 and L2 focus the laser beam Lb from the array light source 20 into parallel light. The optical axis C1 of the front group lenses L1 and L2 is the center of the lenses L1 and L2. In this example, two combination lenses are used as the front group lens, but the front group lens may be an optical system capable of condensing the laser beam Lb from the array light source 20 and constitutes the front group lens. The number of lenses to be used may be one or three or more. Further, the front group lens may be composed of either a spherical lens or an aspherical lens. Further, the front group lens may include an optical member such as a prism.

The rear group lens L3 is composed of, for example, a plano-convex lens, incident light focused by the front group lenses L1 and L2, and focused the light on the phosphor wheel 30. The optical axis C2 of the rear lens group L3 is the center of the lens L3. It should be noted here that in the illumination optical system 10 of this embodiment, the optical axis C2 of the rear group lens is an optical system shifted from the optical axis C1 of the front group lens, and the front group lenses L1 and L2 The shift amount of the optical axes C1 and C2 is adjusted so that the focused laser light Lb is incident on one half of the rear lens group L3. In the example of the figure, the rear group lens L3 is configured by using one lens, but the rear group lens may be any shift optical system capable of condensing the laser beam Lb on the phosphor wheel 30. The number of lenses constituting the rear group lens may be a plurality of combination lenses. Further, the rear group lens may be composed of either a spherical lens or an aspherical lens. Further, the rear group lens may include an optical member such as a prism.

The phosphor wheel 30 is arranged between the rear group lens L3 and the condenser lens L4, and is excited by the blue band laser light that normally reflects and transmits the blue band laser light Lb from the rear group lens L3. Light in the red and green bands is emitted from the opposite surface. The fluorescent wheel will be described in detail later.

The condensing lens L4 is composed of, for example, a plano-convex lens, and condenses light in the red band and the green band emitted from the exit surface side of the phosphor wheel 30. The optical axis C3 of the condenser lens L4 is the center of the lens L4, and preferably the optical axis C3 coincides with the optical axis C2. In this example, the condensing lens L4 is configured by using one lens, and the condensing lens is an optical system capable of condensing the red band and green band light emitted from the phosphor wheel 30. Any combination of lenses may be used, and the number of lenses constituting the condenser lens may be a plurality of combinations. Further, the condenser lens may be composed of either a spherical lens or an aspherical lens.

The reflection mirror 60 reflects the light in the red band and the green band collected by the condenser lens L4 in a direction orthogonal to, for example, the optical axis C3. The reflection mirror 60 may be composed of a total reflection mirror that reflects light in all wavelength bands of blue, red and green, or a dichroic mirror that transmits light in the blue band and reflects light in the red and green bands. It may be composed of. In the latter case, it is possible to effectively prevent the light in the blue band transmitted by the phosphor wheel 30 without being used for wavelength conversion in the red band and the green band from being mixed with the light in the red band and the green band. it can.

FIG. 3 shows a configuration example of the phosphor wheel 30 of this embodiment. 3A is a plan view of the entrance surface side of the phosphor wheel 30, FIG. 3B is a plan view of the emission surface side of the phosphor wheel 30, and FIG. 3C is FIG. 3B. It is a sectional view taken along line XX. The circle indicated by P in the figure represents the spot of the light Lb in the blue band focused by the rear lens group L3.

The phosphor wheel 30 includes a disk-shaped transparent substrate 32, a dichroic mirror 34A and a reflection mirror 34B formed on the incident surface side of the transparent substrate 32, and a phosphor layer 36R formed on the exit surface side of the transparent substrate 32. It is configured to include 36G. The phosphor wheel 30 is preferably circular, but is not necessarily limited to such a shape, and may be polygonal or elliptical, for example.

The transparent substrate 32 is made of a material that transmits light in all bands of R, G, and B, and is made of, for example, glass. As shown in FIG. 3A, the dichroic mirror 34A is formed on the incident surface side of the transparent substrate 32, transmits light in the blue band, and reflects light in the red band and green band. In the example shown in the figure, the dichroic mirror 34A is formed in a fan shape in a region having an internal angle of approximately 240 degrees. However, the region where the dichroic mirror 34A is formed coincides with or overlaps with the regions of the phosphor layers 36R and 36G that develop light in the red band and the green band formed on the exit surface side of the transparent substrate 32. The dichroic mirror 34A is synonymous with a dichroic filter.

A reflection mirror 34B that reflects light Lb in the blue band is formed in a region of the transparent substrate 22 on the incident surface side where the dichroic mirror 34A is not formed. The reflection mirror 34B may be a dichroic mirror that reflects light in at least the blue band, or may be a total reflection mirror that reflects light in all bands R, G, and B. A reflection mirror is synonymous with a reflection layer, a reflection member, a reflection filter, and the like.

As shown in FIG. 3B, a phosphor layer 36R that develops light in the red band and a phosphor layer 36G that develops light in the green band are formed on the exit surface side of the transparent substrate 32. The phosphor layer 36R is excited by the light in the blue band transmitted through the dichroic mirror 32 and emits the light in the red band. The phosphor layer 36G is excited by the light in the blue band transmitted through the dichroic mirror 32 and emits the light in the green band. In the example shown in the figure, the phosphor layers 36R and 36G correspond to the size of the dichroic mirror 34A, and their internal angles are formed in a fan shape of 120 degrees. However, this is only an example, and the internal angles of the phosphor layers 36R, 36G, the dichroic mirror 34A, and the reflection mirror 34B can be appropriately selected according to the required brightness of R, G, B, and the like. The surface of the transparent substrate is exposed in the region where the phosphor layers 36R and 36G on the exit surface side of the transparent substrate 32 are not formed.

The fluorescent material constituting the fluorescent layer 36R and 36G includes YAG (yttrium aluminum garnet) type, TAG (terbium aluminum garnet) type, sialon type, BOS (barium orthosilicate) type, and nitride compound type. It has been known. The phosphor layers 36R and 36G are, for example, coated on the surface of the base material by mixing the phosphor material with the resin material or the ceramic material, or are attached to the sheet-like material mixed with the phosphor material and the surface of the base material. You may attach it.

In the above example, the phosphor wheels 30 are formed with phosphor layers 36R and 36G for emitting light in the red band and the green band, but the light is excited by the blue laser light and is wavelength-converted. Is not necessarily limited to light in the red and green bands. For example, it may include a phosphor layer that excites light in the yellow, magenta, and cyan bands.

Next, the operation of the illumination optical system of this embodiment will be described. 4A, 4B, and 4C are schematic views illustrating the generation of light in the blue band, the green band, and the red band, respectively. First, the generation of the blue band will be described with reference to FIG. 4 (A). The light Lb in the blue band focused by the front group lenses L1 and L2 is incident on one half of the rear group lens L3 in which the optical axis C2 is shifted, and the incident blue band light is directed toward the optical axis C2. It is deflected and focused on the phosphor wheel 30. The light Lb in the blue band is normally reflected when irradiating the reflection mirror 34B of the phosphor wheel 30. That is, the light Lb in the blue band is incident on the reflection mirror 34B with respect to the optical axis C2 at an incident angle θ1, and is normally reflected at an emission angle θ2 (θ1 = θ2) equal to the incident angle θ1. The normally reflected light Lb is incident on one half of the rear group lens L3 on the opposite side and is focused toward the reflection mirror 50.

Next, the generation of light in the red band and the green band will be described with reference to FIG. 4 (B). When the laser beam Lb in the blue band from the rear lens group L3 irradiates the dichroic mirror 34A of the phosphor wheel 30, the light Lb in the blue band passes through the dichroic mirror 34A and the transparent substrate 32 and passes through the dichroic mirror 34A and the transparent substrate 32, and the phosphor layer 36R or 36G. Is incident on. The phosphor material is excited by the laser light Lb in the blue band and emits light in the red band or the green band. As shown in the schematic diagram of FIG. 4B, when the virtual emission point of the phosphor excited by the laser beam Lb in the blue band is W, the emission point W is isotropic, that is, lumbar cyan. R or B light is emitted so as to form (uniformly diffuse). Therefore, a part of the fluorescently colored R or B travels toward the entrance surface side of the phosphor wheel 30, but the light of the R or B is reflected by the dichroic mirror 34A toward the exit surface side of the phosphor wheel 30. Therefore, it is possible to improve the extraction efficiency of R or G and increase the brightness of R and B.

By rotating the phosphor wheel 30 in this way, the dichroic mirror 34A and the reflection mirror 34B are optically scanned by the spot P, and the light Lb in the blue band is extracted from the incident surface side of the phosphor wheel 30 and is emitted from the exit surface side. The red band and green band light Lr / Lg are extracted from the light Lr / Lg.

The R, G, and B lights generated by the illumination optical system 10 are used as a light source such as a projector or an endoscope. For example, the light of R, G, and B is sequentially incident on a light tunnel (not shown), and the light of R, G, and B emitted from the light tunnel illuminates the digital mirror device (DMD). In the DMD, a plurality of mirror elements are formed in a two-dimensional array, and each mirror element is tilted to a first angle or a second angle according to digital image data, and R, G, and B light reflected by the DMD. Generates a projected image. Further, white light can be generated by synthesizing the R, G, and B lights generated by the illumination optical system 10 and incident on an optical fiber to be used as a light source for an endoscope.

The illumination optical system of this embodiment can reduce the number of required optical members and obtain a compact configuration. Further, in the illumination optical system of this embodiment, the light in the blue band is extracted from the incident surface side of the phosphor wheel, and the light in the red band and the green band is extracted from the exit surface side. Therefore, the light in the blue band is red. It is possible to effectively suppress color mixing with light in the band and the green band.

The phosphor wheel according to the above embodiment shows an example in which the optical filters of the dichroic mirror 34A and the reflection mirror 34B are formed on the incident surface side of the transparent substrate, and the optical filters of the phosphor layers 36R and 36G are formed on the exit surface side. However, this is an example, and the phosphor wheel is not limited to such a configuration. For example, in the phosphor wheel, the side surfaces of the dichroic mirror 34A and the reflection mirror 34B are joined with an adhesive or the like without using a transparent substrate, and the phosphor layers 36R and 36B are directly laminated or attached to the back surface of the dichroic mirror. You may try to do it.

Further, in the above embodiment, the reflection mirror 34B is formed on the transparent substrate, but instead of forming the reflection mirror 34B, a part of the transparent substrate is made of at least a material that reflects light in the blue band. May be good.

Further, the surface of the reflection mirror 34B may be formed with an uneven diffusion surface that slightly diffuses the incident blue band light to suppress the speckle of the blue laser light.

Next, a second embodiment of the present invention will be described. FIG. 5 shows the illumination optical system 10A according to the second embodiment, and the same reference number is assigned to the same configuration as that of FIG. In the second embodiment, as shown in the figure, a dichroic mirror 70 is provided between the condenser lens L4 and the reflection mirror 60. The dichroic mirror 70 is configured to reflect light in the blue band and transmit light in the other bands, ie, in this example, the red and green bands. The dichroic mirror 70 is arranged substantially parallel to the phosphor wheel 30, emits the light focused by the condenser lens L4, and reflects the light Lb in the blue band contained in the light toward the phosphor wheel 30. ..

Most of the blue band light Lb incident on the phosphor layers 36R and 36G from the rear group lens L3 excites the phosphor and is converted into red band and green band light, but in some blue band. The light Lb may pass through the phosphor layers 36R and 36G without being used for wavelength conversion. Then, the light Lr / Lg in the red and green bands is mixed with the light Lb in the blue band, which is not preferable. Therefore, in the second embodiment, the light Lb in the blue band transmitted through the phosphor layers 36R and 36G without contributing to the fluorescence color development is reflected by the dichroic mirror 70, and the light Lb in the blue band is reflected by the phosphor layer 36R. , 36G is incident, and the light in the blue band is reused for fluorescent color development. As a result, the conversion efficiency by the phosphor is improved, and at the same time, it is possible to prevent the light in the blue band from being mixed with the light in the red band and the green band.

Next, a third embodiment of the present invention will be described. FIG. 6 is a diagram showing the principle of the illumination optical system 10B according to the third embodiment. The third embodiment includes two sets of the rear group lens L3, the condenser lens L4, the reflection mirror 50 and the reflection mirror 60 used in the first embodiment, and is blue from the front group lenses L1 and L2 (not shown). The band laser beam Lb is split into two light fluxes by a beam splitter 100, and R, G, and B are generated from the respective optical systems. However, the number of fluorescent material wheels is singular without using a plurality of them, and two sets of fluorescent material layers 36R, 36G and the like are formed on the surface thereof in the circumferential direction.

As shown in the figure, the parallel laser beam Lb from the front lens group lenses L1 and L2 is split into two ray bundles Lb1 and Lb2 by the beam splitter 100. The ray bundle Lb2 is further reflected at a substantially right angle by the reflection mirror 110 to be parallel to the ray bundle Lb1. The two ray bundles Lb1 and Lb2 are incident on one half of each of the two rear lens group lenses L3 whose optical axes are shifted, as in the case of the first embodiment. The light bundle Lb1 is focused on the outer peripheral side of the phosphor wheel 30, and the spot P optically scans the phosphor wheel 30, and the light bundle Lb2 is focused on the inner peripheral side of the phosphor hole 30 and spotted. Optically scan the fluorophore wheel with Q. The blue band lights Lb1 and Lb2 reflected by the phosphor wheel 30 are reflected by the two reflection mirrors 50 and then combined by the condenser lens L5.

Further, the red band and green band light Lr and Lg excited by the blue band light Lb1 and Lb2 transmitted through the phosphor wheel 30 are focused by the two focusing lenses L4, respectively, and then two reflection mirrors. Each is reflected by 60 and then synthesized by the condenser lens L6.

FIG. 6C shows the combined luminance of R, G, and B when the phosphor wheel is scanned at the spot P and the spot Q. The arrangement of the phosphor layers 36R, 36G and the reflection mirror 34B formed on the outer peripheral side of the phosphor wheel 30 and the arrangement of the phosphor layers 36R, 36G and the reflection mirror 34B formed on the inner peripheral side are R, G, The timing at which G is generated is adjusted to be synchronized.

FIG. 7 shows the relationship between the emission conversion efficiency of the phosphor and the irradiation energy density of the excitation light. It is known that the phosphor has a linear region in which the emission conversion efficiency increases, a saturation region in which the emission conversion efficiency is saturated, and a deterioration region in which the emission conversion efficiency deteriorates as the irradiation energy density of light increases. .. Therefore, when the phosphor layers 36R and 36G are irradiated with blue light having a certain energy or more, the emission conversion efficiency is saturated or deteriorated, and the phosphor is thermally damaged or deteriorated. In order to prevent heat damage and the like, it is necessary to cool the phosphor layer or the phosphor wheel. Further, the emission conversion efficiency of the phosphor deteriorates with time.

In the third embodiment, even if the irradiation energy of the light in the blue band as the excitation light is increased, the light in the blue band is divided into two to form two sets of phosphor layers on the phosphor wheel. Therefore, the irradiation energy applied to the phosphor layer can be substantially halved. This makes it possible to use the phosphor in the linear region and prevent the emission conversion efficiency from deteriorating. At the same time, it is possible to suppress thermal damage or thermal deterioration of the phosphor layer, and it is possible to extend the life of the phosphor.

In the third embodiment, an example in which the light beam bundle Lb is separated into two is shown, but the light beam bundle Lb is divided into n pieces, and n sets of phosphor layers 36R and 36G (and a dichroic mirror 34A and a reflection mirror 34B) are shown. ) Can also be formed in the radial direction of the phosphor wheel. Further, in the configuration shown in FIG. 6, two sets of a condenser lens L4 and a reflection mirror 60 that collect the R / G light emitted from the phosphor wheel 30 are prepared, but the condenser lens L4 and the reflection mirror 60 are There may be one.

The illumination optical systems according to the first to third embodiments described above may be implemented independently, or the first to third embodiments may be combined and implemented. Further, in the first to third embodiments, the light of R, G, and B can be used individually, or can be used as the light of sequential R, G, and B. Further, it is also possible to combine the R, G, and B lights into white light. 8 (A) to 8 (D) show an example of an optical system for synthesizing R, G, and B. In FIG. 8A, the red and green band light Lr / Lg is reflected by the reflection mirror 200 at a right angle toward the dichroic mirror 210. The dichroic mirror 210 transmits B and reflects R and G, whereby R / G / B is synthesized. Further, in FIG. 8B, the dichroic mirror 210A is configured to reflect B and pass through R and B, and in this case, white light synthesized as in FIG. 8A is emitted. The directions are different by 90 degrees. In the optical system of FIG. 8C, the light Lb in the blue band reflected by the reflection mirror 50 is reflected by the reflection mirror 220 at a right angle toward the dichroic mirror 230. The dichroic mirror 230 is configured to reflect B and transmit R and G, whereby R / G / B is synthesized. In FIG. 8D, the dichroic mirror 230A is configured to transmit B and reflect R and G, and the combined light of R / G / B in the direction orthogonal to that in FIG. 8C. Is emitted. By using such an optical system, the illumination optical system according to the present invention can be used as a light source for a projector, a rear projector, an endoscope, a lighting device, or the like.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various aspects are within the scope of the gist of the present invention described in the claims. It can be transformed and changed.

10, 10A, 10B: Illumination optics 20: Array light source 30: Phosphoric wheel 34A: Dichroic mirror 34B: Reflective mirror 36R, 36B: Phosphorant layer 40: Motor 50: Reflective mirror 60: Reflective mirror 70: Dichroic mirror 100: Beam splitter 110: Reflective mirrors L1, L2: Front group lens L3: Rear group lens L4, L5: Condensing lens

Claims (2)

A light source that emits light in the blue band,
Incident light in the blue band, at least the blue band, a rotary member which emits light of red wavelength range and green bands, the rotary body includes a first surface, a second opposite to the first surface The first surface is formed with a reflection region that reflects at least blue band light and a dichroic region that transmits blue band light and reflects at least red band and green band light. On the second surface, a first phosphor region that emits light in the red band based on the light in the blue band transmitted through the dichroic region and a second phosphor region that emits light in the green band are formed. is the, with the rotary body,
A first optical system arranged between the rotating body and the light source and condensing light in the blue band from the light source on the first optical axis.
It has a second optical axis shifted from the first optical axis, and has a second optical system that concentrates the light in the blue band focused by the first optical system on the rotating body. The illumination optical system, in which the light collected by the first optical system is incident on one half of the lens of the second optical system. The illumination optical system according to claim 1, wherein a plurality of sets of the first and second phosphor regions are formed in the radial direction of the second surface.

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