projector

Abstract

To prevent, in a single plate type projector, deformation and alteration of a lens arranged on an optical path closer to a light source than a reflective polarizer, and reduction in optical performance of the lens.SOLUTION: A projector of the present invention comprises: a light source that emits first light; a wavelength conversion element that is irradiated with the first light and emits second light having an emission wavelength different from that of the first light; an optical system that enlarges a beam of the first light and a beam of the second light from the wavelength conversion element; a collimating lens that collimates the rays of light enlarged by the optical system; an optical modulation element that converts the incident light to generate image light; an emission-side polarization element that makes incident the image light emitted from the optical modulation element; a projection lens that projects the image light emitted from the emission-side polarization element; and an incident-side polarization element that transmits polarized light in a predetermined polarization direction and reflects polarized light in directions other than the predetermined polarization direction. Non-linear polarized light is incident on the incident-side polarization element, and on an optical path of the second light, the incident-side polarization element is arranged between the light source and the collimating lens.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a projector. [Background technology]

[0002] In recent years, a single liquid crystal panel has been used as a light modulation element to generate image light of a given color from color light. Projectors, that is, single-panel projectors, are known. For example, Patent Document 1 In the single-panel projector disclosed in Placed near Become A reflective polarizing plate is installed between the Fresnel lens on the incident side and the liquid crystal panel. The light emitted from the light source passes through the condenser lens and the Fresnel lens on the input side. When light enters a reflective polarizing plate through a The light passes through the liquid crystal panel and is modulated into image light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] China Utility Model No. 201622432 Summary of the Invention [Problem to be solved by the invention]

[0004] In the projector disclosed in the above-mentioned Patent Document 1, when light emitted from a light source is incident on a reflective polarizing plate, at least a part of the polarized light other than the predetermined polarization direction of the incident light returns to the Fresnel lens on the incident side, and the amount of light absorbed and heat generated by the Fresnel lens on the incident side increases. That is, it is considered that deformation of the lens arranged in an area closer to the light source than the reflective polarizing plate occurs, and a loss in the amount of light incident on the lens and the amount of light emitted from the lens occurs. For example, if the lens is made of resin, yellowing of the lens may occur. Therefore, in a single-plate projector, a measure has been required to prevent deformation, deterioration, and deterioration of the optical function of the lens arranged on the optical path closer to the light source than the reflective polarizing plate. [Means for solving the problem]

[0005] In order to solve the above problem, a projector according to one embodiment of the present invention emits a first light. and a wavelength converter that is irradiated with a first light and emits a second light having an emission wavelength different from that of the first light. A conversion element, a light beam of a first light transmitted through the wavelength conversion element, and a second light emitted from the wavelength conversion element. and a collimating lens that collimates the light expanded by the optical system. The light collimated by the collimating lens is then incident on the lens, and the incident light is modulated to generate image light. an exit side polarizing element into which the image light emitted from the light modulation element is incident; A projection lens projects the image light emitted from the side polarizing element, and a polarized light having a predetermined polarization direction is transmitted through the projection lens. and an incident side polarizing element that reflects polarized light other than the predetermined polarization direction. The incident polarizing element is parallel to the light source on the optical path of the second light. It is placed between the In order to solve the above problem, a projector according to one aspect of the present invention includes a first light source. a light source that emits the first light and a second light source that emits the second light and has an emission wavelength different from that of the first light. A wavelength conversion element that emits light, and a light flux of the first light that has passed through the wavelength conversion element and the wavelength an optical system for expanding the luminous flux of the second light emitted from the conversion element; a collimating lens for collimating the amplified light; and A light modulation element that modulates the incident light to generate image light, and a light output from the light modulation element an exit side polarizing element into which the image light having been incident is polarized; and A projection lens that projects light having a predetermined polarization direction and transmits polarized light having a polarization direction other than the predetermined polarization direction. and an incident-side polarizing element that reflects nonlinearly polarized light. On the optical path of the second light, the incident side polarizing element is disposed between the light source and the collimating lens. the incident-side polarizing element is disposed between the wavelength conversion element and the optical system. 。 [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a projector according to a first embodiment. [Diagram 2] 2 is a schematic diagram for explaining the configurations of a light-emitting section and an incident-side polarizing element of the projector in FIG. 1 and the behavior of light therein. [Diagram 3] 13 is a schematic diagram showing the configurations of a light-emitting section and an incident-side polarizing element of a projector according to a second embodiment. FIG. [Figure 4] 13 is a schematic diagram showing the configurations of a light-emitting section and an incident-side polarizing element of a projector according to a third embodiment. FIG. [Diagram 5] 13 is a schematic diagram showing the configurations of a light-emitting section and an incident-side polarizing element of a projector according to a fourth embodiment. FIG. [Figure 6] 13 is a schematic diagram showing the configurations of a light-emitting section, an incident-side polarizing element, and an optical system that expands white light of a projector according to a fifth embodiment. FIG. [Figure 7] 13 is a schematic diagram showing the configurations of a light-emitting section, an optical system, and an entrance-side polarizing element of a projector according to a sixth embodiment. FIG. [Figure 8] 13 is a schematic diagram showing the configurations of a light-emitting section, an optical system, and an entrance-side polarizing element of a projector according to a seventh embodiment. FIG. [Figure 9] 13 is a schematic diagram showing the configurations of a light-emitting section, an optical system, a retardation plate, and an entrance-side polarizing element of a projector according to an eighth embodiment. FIG. [Figure 10] 23 is a graph showing the results of a simulation in which the effective utilization efficiency of blue light and yellow light in a projector according to an eighth embodiment is calculated. [Figure 11]13 is a schematic diagram showing the configurations of a light-emitting section, a rod member, and an incident-side polarizing element of a projector according to a ninth embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] [First embodiment] A first embodiment of the present invention will be described below with reference to Figs. 1 and 2. In the following drawings, the dimensions of some components may be scaled differently to make the components easier to see. Fig. 1 is a schematic diagram showing the configuration of a projector 101 according to the first embodiment. The projector 101 is an image display device that uses one liquid crystal panel as a light modulation element, and is a so-called single-panel projector.

[0008] As shown in FIG. 1, a projector 101 includes a light-emitting unit 10 and , Pi Back-up Lens 30 a parallelizing lens 35, a light modulation element 40, an exit side polarizing element 50, and a projection optical system 70. , and an incident side polarizing element 80.

[0009] The light-emitting unit 10 emits white light WL. In the following description, one direction parallel to the light-emitting surface 10s of the light-emitting unit 10 is the X direction, and a direction parallel to the light-emitting surface 10s and perpendicular to the X direction is the Y direction. The direction perpendicular to the light-emitting surface 10s, the X direction, and the Y direction is the Z direction. The detailed configuration of the light-emitting unit 10 will be described later. The light-emitting surface 10s of the light-emitting unit 10 in the first embodiment corresponds to the light-emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13 described later. The white light WL emitted from the light-emitting unit 10 is divergent light that diverges from the light-emitting surface with the Z direction as a reference, and is non-linearly polarized light, for example, randomly polarized light. In this specification, non-linearly polarized light means that the direction in which the electric field vector oscillates is not linearly polarized light in only one direction, and may include, for example, multiple linearly polarized light whose electric field vector oscillates in different directions, for example, including random polarization and elliptical polarization. The direction in which the electric field vector of light oscillates may be described as the polarization direction.

[0010] The incident-side polarizing element 80 is disposed on the optical path of the white light WL emitted from the light-emitting unit 10. The incident-side polarizing element 80 is a reflective polarizing element that transmits polarized light of a predetermined polarization direction out of the white light WL emitted from the light-emitting unit 10 and reflects polarized light of a direction other than the predetermined polarization direction. The incident-side polarizing element 80 is, for example, a reflective polarizing plate 82 that has sensitivity to the visible wavelength band. The polarized light of the predetermined polarization direction is, for example, P-polarized light or S-polarized light.

[0011] The pickup lens 30 is disposed on the optical path of the white light WL that passes through the incident-side polarizing element 80 and is emitted from the incident-side polarizing element 80. The pickup lens 30 expands the light flux of the blue light BL and the light flux of the yellow light YL contained in the white light WL emitted from the incident-side polarizing element 80 in an XY plane including the X and Y directions. The white light WL emitted from the incident-side polarizing element 80 corresponds to the "light flux of the first light transmitted through the wavelength conversion element" and the "light flux of the second light emitted from the wavelength conversion element" described in the claims below. The pickup lens 30 is, for example, a plano-convex lens 32 having a convex curved surface that is convex toward the emission side of the expanded white light WL. The pickup lens 30 may be composed of a plurality of lenses. Alternatively, instead of the pickup lens 30, an optical element capable of expanding the white light WL in the XY plane may be disposed. The pickup lens 30, or an optical element capable of magnifying the white light WL, corresponds to "an optical system for magnifying a luminous flux of a first light transmitted through a wavelength conversion element and a luminous flux of a second light emitted from the wavelength conversion element" described in the claims below.

[0012] The parallelizing lens 35 is disposed on the optical path of the white light WL emitted from the pickup lens 30. The parallelizing lens 35 parallelizes the white light WL enlarged by the pickup lens 30 along the Z direction. The parallelizing lens 35 is, for example, a Fresnel lens 37 having a lens surface that is convex on the incident side of the white light WL, i.e., a phase modulation surface. By using the Fresnel lens 37, the thickness of the parallelizing lens 35 can be suppressed even if the diameter of the parallelizing lens 35 is large.

[0013] The light modulation element 40 is disposed on the optical path of the white light WL emitted from the collimating lens 35. That is, the white light WL emitted from the collimating lens 35 is incident on the light modulation element 40. The white light WL emitted from the collimating lens 35 corresponds to "light collimated by the collimating lens" described in the claims below. The light modulation element 40 modulates the incident white light WL to generate full-color image light IM. The light modulation element 40 is, for example, a transmissive liquid crystal panel 42.

[0014] The liquid crystal panel 42 includes a liquid crystal element 43 and a plurality of color filters 44R, 44G, and 44B. Although not shown in detail, the liquid crystal element 43 has a plurality of pixels. Each pixel of the liquid crystal element 43 has sub-pixels corresponding to red, green, and blue colors. Each sub-pixel has a switching element. An example of the switching element is a polysilicon thin film transistor (TFT). Although not shown in detail, an absorptive polarizing element may be provided between the collimating lens 35 and the liquid crystal element 43.

[0015] As an absorption type polarizing element, for example, polyvinyl alcohol (Polyvinyl A A polarizing film made by stretching a polyvinyl alcohol (PVA) film in one direction and absorbing and dispersing iodine was Polarizing film made by stretching PVA film in one direction, which has been chemically treated to give it dichroic properties. PVA-metal-based polarized films are made by adsorbing metals such as gold, silver, copper, mercury, and iron onto PVA-based films. The optical film and PVA-based film were treated with a boric acid solution containing potassium iodide and sodium thiosulfate. The near-ultraviolet polarizing film and the PVA-based film made of modified PVA containing cationic groups in the molecule A polarizing element having a dichroic dye on at least one of the surface and the interior of the film can be used. The transmission axis of the absorptive polarizing element is oriented in a direction opposite to that of the incident side polarizing element 80 described later. It is preferable that the incident side Light beam transmitted through the polarizing element 80 When the polarization state of the light is shifted, the noise caused by the shift can be absorbed by an absorptive polarizing element. can.

[0016] The multiple color filters 44R, 44G, and 44B are provided on a plate surface 43a of the liquid crystal element 43 on the side where the white light WL is incident. The multiple color filters 44R are arranged corresponding to the red sub-pixels of the multiple pixels of the liquid crystal element 43. The multiple color filters 44G are arranged corresponding to the green sub-pixels of the multiple pixels of the liquid crystal element 43. The multiple color filters 44B are arranged corresponding to the blue sub-pixels of the multiple pixels of the liquid crystal element 43.

[0017] The color filter 44R transmits red light of the incident white light WL. The sub-pixel of the liquid crystal element 43 on which the color filter 44R is arranged modulates the polarization direction of the red light transmitted through the color filter 44R by the operation of a switching element to generate red image light. The color filter 44G transmits green light of the incident white light WL. The sub-pixel of the liquid crystal element 43 on which the color filter 44G is arranged modulates the polarization direction of the green light transmitted through the color filter 44G by the operation of a switching element to generate green image light. The color filter 44B transmits blue light of the incident white light WL. The sub-pixel of the liquid crystal element 43 on which the color filter 44B is arranged modulates the polarization direction of the blue light transmitted through the color filter 44B by the operation of a switching element to generate blue image light. The three primary color image lights emitted from the multiple pixels of the liquid crystal element 43 are combined with each other to emit full-color image light IM.

[0018] 1, the color filters 44R, 44G, and 44B are repeatedly arranged in this order on the plate surface 43a of the liquid crystal element 43, but it is sufficient that sub-pixels that modulate different color lights are adjacent to each other in each pixel corresponding to the color filters 44R, 44G, and 44B. Therefore, the arrangement and order of the color filters 44R, 44G, and 44B are not limited to the example shown in FIG.

[0019] The exit side polarizing element 50 is disposed on the optical path of the image light IM emitted from the light modulation element 40. The exit side polarizing element 50 is provided, for example, on the plate surface 43b opposite to the plate surface 43a of the liquid crystal element 43 of the liquid crystal panel 42 of the light modulation element 40. The plate surface 43b is the plate surface of the liquid crystal element 43 from which the image light IM is emitted. The exit side polarizing element 50 transmits polarized light having an appropriate polarization direction based on a predetermined polarization direction of the image light IM emitted from the light modulation element 40, and absorbs polarized light having a polarization direction other than the appropriate polarization direction. That is, the image light IM emitted from the light modulation element 40 enters the exit side polarizing element 50 and is converted into polarized light having an appropriate polarization direction. The exit side polarizing element 50 is, for example, an absorption type polarizing plate 52 having sensitivity to the visible wavelength band.

[0020] A condenser lens 60 is provided on the optical path of the image light IM emitted from the emission-side polarizing element 50. The condenser lens 60 reflects the image light IM emitted from the exit-side polarizing element 50 along the Z direction. The condenser lens 60 has a lens surface that is convex on the side where the image light IM emerges, i.e., The Fresnel lens 62 has a phase modulation surface. As a result, even if the diameter of the condenser lens 60 is large, the thickness of the condenser lens 60 can be suppressed. The image light IM emitted from the optical lens 60 is a Emitted from the exit polarizing element Picture This corresponds to "image light".

[0021] The projection optical system 70 is disposed on the optical path of the image light IM emitted from the condenser lens 60. The projection optical system 70 projects the image light IM emitted from the emission-side polarizing element 50, and displays a full-color image based on the image light IM on a screen (not shown) provided in front of the projection optical system 70 in the traveling direction of the image light IM. The projection optical system 70 is composed of, for example, a plano-convex lens 71, a biconcave lens 72, and a biconvex lens 73. The projection optical system 70 may be composed of two or less optical lenses, or four or more optical lenses. Each optical lens is not limited to a plano-convex lens, a biconcave lens, or a biconvex lens, and may be a meniscus lens, a free-form lens, or an aspheric lens. The projection optical system 70 corresponds to a "projection lens" described in the claims described later.

[0022] Fig. 2 is a schematic diagram of the main parts of the projector 101 in Fig. 1, and is a diagram for explaining the configuration of the light-emitting unit 10 and the behavior of light in the light-emitting unit 10 and the incident-side polarizing element 80. As shown in Fig. 2, the light-emitting unit 10 is composed of a substrate 11, a light source 12, and a wavelength conversion element 13. The substrate 11 has a plate surface 11b parallel to the XY plane.

[0023] The light source 12 is provided on the plate surface 11b of the substrate 11. The number of light sources 12 included in the light-emitting unit 10 is not limited to a specific number, but the light-emitting unit 10 includes, for example, a plurality of light sources 12. The plurality of light sources 12 are arranged at intervals from each other in the X direction and the Y direction on the plate surface 11b of the substrate 11. The light source 12 emits blue light BL. The emission wavelength of the blue light BL is, for example, 440 nm to 480 nm, but is not limited as long as it is a wavelength band belonging to the blue wavelength band of the visible wavelength band.

[0024] The light source 12 is a light emitting diode (LED) that emits blue light BL. The blue light BL is radially emitted from a light emitting surface 12s of the light source 12 opposite to a bottom surface 12a that contacts the plate surface 11b of the substrate 11.

[0025] The wavelength conversion element 13 is disposed so as to cover the light emitting surfaces 12s of the multiple light sources 12. The wavelength conversion element 13 converts the wavelength of the blue light BL emitted from the light source 12 into yellow light YL, and emits the yellow light YL. The wavelength conversion element 13 is, for example, a phosphor layer 14 formed parallel to the XY plane. The phosphor layer 14 has an incident surface 14a in contact with the light emitting surfaces 12s of the multiple light sources 12, and a light emitting surface 14s on the opposite side to the incident surface 14a. The incident surface 14a of the phosphor layer 14 is in contact with the light emitting surfaces 12s of the multiple light sources 12. The blue light BL emitted from the light source 12 enters the phosphor layer 14 from the incident surface 14a and is scattered. At least a part of the blue light BL that enters the phosphor layer 14 acts as excitation light and generates yellow light YL1 as fluorescence. That is, the phosphor layer 14 emits yellow light YL from the light emitting surface 14s. On the other hand, at least a portion of the remaining blue light BL is internally scattered in the phosphor layer 14, passes through the phosphor layer 14, and is emitted approximately radially from the light-emitting surface 14s. As a result, the blue light BL and the yellow light YL are emitted radially from the wave source WS1 on the light-emitting surface 14s of the phosphor layer 14.

[0026] The emission wavelength of the yellow light YL is, for example, 500 nm to 670 nm, but is not limited as long as it is a wavelength band belonging to the yellow wavelength band of the visible wavelength band. The blue light BL emitted by the light source 12 corresponds to the "first light" described in the claims below. The yellow light YL emitted by the wavelength conversion element 13 corresponds to the "second light" described in the claims below, and has an emission wavelength different from that of the first light. The yellow light YL includes green light and red light.

[0027] The phosphor layer 14 is formed of, for example, a ceramic phosphor of yttrium aluminum garnet (YAG). The phosphor of the phosphor layer 14 is, for example, YAG activated with cerium (Ce). 3+ ) The phosphor layer 14 may contain one type of phosphor, or may contain a mixture of particles made of two or more types of phosphor materials.

[0028] The blue light BL emitted from the light source 12 and transmitted through the wavelength conversion element 13 and the yellow light YL1 emitted from the wavelength conversion element 13 are nonlinearly polarized light, for example, randomly polarized light. In FIG. 2, the polarization directions of the blue light BL and the yellow light YL are illustrated as being parallel to the X direction and the Y direction. Among the nonlinearly polarized light of the blue light BL transmitted through the wavelength conversion element 13 and the yellow light YL1 emitted from the wavelength conversion element 13, the blue light BL2 and the yellow light YL2 having a predetermined polarization direction set according to the specifications and optical characteristics of the liquid crystal panel 42 of the light modulation element 40 are transmitted through the polarizing plate 82 of the incident side polarizing element 80. The predetermined polarization direction is, for example, parallel to the Y direction, which is the vertical direction of the paper in FIG. 1 and the horizontal direction of the paper in FIG. 2.

[0029] On the other hand, among the nonlinearly polarized light of the blue light BL1 transmitted through the wavelength conversion element 13 and the yellow light YL1 emitted from the wavelength conversion element 13, the blue light BL3 and the yellow light YL3 having a polarization direction other than the predetermined polarization direction are reflected by the polarizing plate 82 of the incident side polarizing element 80. The blue light BL3 is irradiated onto the light emitting surface 14s of the phosphor layer 14, enters the phosphor layer 14 from the light emitting surface 14s, acts as excitation light, and generates the yellow light YL4 as fluorescence. The yellow light YL4 is radially emitted from the wave source WS2 on the light emitting surface 14s of the phosphor layer 14. The yellow light YL4 includes randomly polarized light and elliptically polarized light. As with the above-mentioned yellow light YL1, among the polarized light of the yellow light YL4, the yellow light YL5 having a predetermined polarization direction is transmitted through the polarizing plate 82 of the incident side polarizing element 80. Of the polarized light of the yellow light YL4, the yellow light YL (not shown) having a polarization direction other than the predetermined polarization direction is reflected by the polarizing plate 82 of the incident-side polarizing element 80.

[0030] As described above, the blue light BL1 and the yellow light YL1, YL4 are repeatedly emitted from the wavelength conversion element 13. In addition, the transmission of the blue light BL1 and the yellow light YL2, YL5 from the incident-side polarizing element 80 and the reflection of the blue light BL3 and the yellow light YL3 are repeatedly generated. A plurality of wave sources WS1, WS2 are generated on the light-emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13. In the wavelength conversion element 13 in the vicinity of each wave source WS1 with the plurality of wave sources WS1 at the center, the blue light BL is emitted as divergent light, and the yellow light YL, which is fluorescent light, is emitted. In the wavelength conversion element 13 in the vicinity of each wave source WS2 with the plurality of wave sources WS2 at the center, re-excitation by the blue light BL occurs, and the randomly polarized yellow light YL is emitted, and the yellow light YL is internally scattered.

[0031] The blue light BL1 and the yellow light YL1, and the blue light BL1 and the yellow light YL4 emitted from the light-emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13 are combined together to behave as nonlinearly polarized white light WL. Similarly, the blue light BL2 and the yellow light YL2 and YL5 emitted from the exit surface 82b opposite to the entrance surface 82a of the polarizing plate 82 of the entrance-side polarizing element 80 are combined together to behave as nonlinearly polarized white light WL.

[0032] Due to the above-mentioned optical behavior, the greater the number of reflections of the blue light BL and the yellow light YL from the incident side polarizing element 80 and the number of re-excitations in the phosphor layer 14 of the wavelength conversion element 13 in the light-emitting unit 10 and the greater the number of times the yellow light YL is emitted, the greater the amount of yellow light YL emitted from the incident side polarizing element 80 is. Therefore, in order to favorably balance the full-color image light IM emitted from the projector 101 of the first embodiment, it is preferable that the amount of blue light BL contained in the white light WL first emitted from the light-emitting unit 10 is greater than the amount of yellow light YL. As a method for increasing the amount of blue light BL first emitted from the light-emitting unit 10, for example, a method of setting the driving current supplied to the light source 12 to be higher, or a method of suppressing the conversion efficiency from blue light BL to yellow light YL in the wavelength conversion element 13 can be mentioned. The conversion efficiency of blue light BL to yellow light YL in the wavelength conversion element 13 can be appropriately adjusted by, for example, changing the concentration of cerium (Ce) in the phosphor of the phosphor layer 14, or changing the porosity of the phosphor, changing the thickness of the phosphor layer, or the ratio or mixing ratio of the constituent elements of the phosphor, thereby changing the composition of the phosphor layer 14.

[0033] That is, the light amount ratio between the blue light BL and the yellow light YL first emitted from the light-emitting unit 10 is appropriately set and adjusted according to the color balance required for the full-color image light IM emitted from the projector 101.

[0034] The projector 101 of the first embodiment described above includes the light source 12, the wavelength conversion element 13, the pickup lens 30, the collimating lens 35, the light modulation element 40, the exit side polarizing element 50, the projection optical system 70, and the entrance side polarizing element 80. The light source 12 emits blue light BL. The wavelength conversion element 13 is irradiated with the blue light BL. The wavelength conversion element 13 emits yellow light YL having an emission wavelength different from that of the blue light BL. The pickup lens 30 expands the light flux of the blue light BL transmitted through the wavelength conversion element 13 and the light flux of the yellow light YL emitted from the wavelength conversion element 13. The collimating lens 35 collimates the white light WL expanded by the pickup lens 30. The white light WL collimated by the collimating lens 35 is incident on the light modulation element 40. The light modulation element 40 modulates the incident white light WL to generate image light IM. The image light IM emitted from the light modulation element 40 is incident on the exit-side polarizing element 50. The projection optical system 70 projects the image light IM emitted from the exit-side polarizing element 50. At least the non-linearly polarized white light WL emitted from the wavelength conversion element 13 is incident on the entrance-side polarizing element 80. The entrance-side polarizing element 80 is a reflective polarizing element that transmits polarized light of a predetermined polarization direction out of the incident white light WL and reflects polarized light of a polarization direction other than the predetermined polarization direction.

[0035] In the projector 101 of the first embodiment, at least on the optical path of the yellow light YL, The incident-side polarizing element 80 is disposed between the light source 12 of the light-emitting unit 10 and the collimating lens 35. The optical paths of the yellow light YL and the white light WL are as described in the claims below. According to the projector 101 of the first embodiment, the incident side polarizing element 80 is disposed on the optical path of the white light WL closer to the light source 12 than the parallelizing lens 35. The incident-side polarizing element 80 is arranged to polarize the white light W L, the incident-side polarizing element 80 is arranged in the direction toward the parallelizing lens 35. Therefore, the amount of white light WL reflected by the reflector 33 and irradiated onto the collimating lens 35 can be reduced. This allows the single-panel projector 101 to ,flat Deformation of the 35th lens and In addition, the light incident on the parallelizing lens 35 in a direction other than a predetermined direction can be prevented from being polarized. The amount of the white light WL having the polarization is suppressed, and the optical function of the parallelizing lens 35 is prevented from being deteriorated. The deterioration of the optical function of the collimating lens 35 may occur, for example, when the light emitted from the collimating lens 35 is This is achieved by reducing the amount of white light WL that is input. The incident-side polarizing element is disposed, for example, on the optical path between the parallelizing lens and the optical modulation element. Therefore, most of the light reflected by the incident polarizing element is irradiated to the collimating lens and is collimated. The lens is easily deformed, deteriorated, and its optical function is easily deteriorated. In particular, the parallelizing lens 35 is easily deformed, and the optical function is easily deteriorated. If the projector is made of transparent resin or plastic, the projector of the first embodiment can be used. The polarizer 101 polarizes white light having a polarization direction other than the predetermined polarization direction that is incident on the parallelizing lens 35. The amount of light WL can be reduced, and the parallelizing lens 35 can be prevented from yellowing or the like.

[0036] In the projector 101 of the first embodiment, the incident side polarizing element 80 is disposed between the wavelength conversion element 13 of the light emitting unit 10 and the pickup lens 30. Therefore, according to the projector 101 of the first embodiment, the amount of white light WL reflected from the incident side polarizing element 80 toward the collimating lens 35 and irradiated to the collimating lens 35 can be reduced as described above, compared to the case where the incident side polarizing element 80 is disposed on the optical path of the white light WL farther from the wavelength conversion element 13 than the collimating lens 35. Also, in the projector 101 of the first embodiment, since the incident side polarizing element 80 is disposed immediately after the wavelength conversion element 13, the amount of blue light BL incident on the wavelength conversion element 13 out of the white light WL reflected from the incident side polarizing element 80 can be increased. This further increases the utilization rate of the blue light BL, which is the excitation light of the yellow light YL as fluorescence, and improves the light utilization efficiency in the projector 101.

[0037] Moreover, in the projector 101 of the first embodiment, the wavelength conversion element 13 has a phosphor layer 14. The light-emitting surface 14s on the opposite side of the incident surface 14a of the phosphor layer 14 facing the light source 12 and the incident surface 82a of the polarizing plate 82 of the incident-side polarizing element 80 are parallel to each other. Therefore, according to the projector 101 of the first embodiment, among the white light WL reflected from the incident-side polarizing element 80, the loss of the blue light BL that is reflected from the polarizing plate 82 of the incident-side polarizing element 80 to the outside in the XY plane from the phosphor layer 14 of the wavelength conversion element 13 and is not used as excitation light can be reduced, and the amount of blue light BL that is incident on the phosphor layer 14 from the light-emitting surface 14s of the phosphor layer 14 can be secured. This can further increase the utilization rate of the blue light BL as excitation light, and improve the light utilization efficiency in the projector 101.

[0038] In the projector 101 of the first embodiment, a polarizing element (not shown) different from the incident-side polarizing element 80 may be provided on the incident-side plate surfaces of the plurality of color filters 44R, 44G, and 44B in the light modulation element 40.

[0039] [Second embodiment] Next, a second embodiment of the present invention will be described with reference to FIG. In each of the second and subsequent embodiments, the same reference numerals are used for configurations common to the higher-level embodiment, and descriptions thereof will be omitted. In each of the second and subsequent embodiments, configurations and contents different from the higher-level embodiment will be described.

[0040] Although not shown, the projector of the second embodiment, like the projector 101 of the first embodiment, is equipped with an emitter 10, an incident side polarizing element 80, a pickup lens 30, a parallelizing lens 35, an optical modulation element 40, an exit side polarizing element 50, and a projection optical system 70.

[0041] 3 is a schematic diagram for explaining the configuration of the light-emitting section 10 and the incident-side polarizing element 80 of the second embodiment. As shown in FIG. 3, in the projector of the second embodiment, the incident-side polarizing element 80 is provided on the light-emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13 of the light-emitting section 10. That is, the incident surface 82a of the polarizing plate 82 of the incident-side polarizing element 80 abuts on the light-emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13.

[0042] The state where the incident side polarizing element 80 is in contact with the wavelength conversion element 13 means that there is almost no space between the incident side polarizing element 80 and the wavelength conversion element 13 in the Z direction, and includes a state where an adhesive or the like that does not affect the behavior of the white light WL is interposed between the incident side polarizing element 80 and the wavelength conversion element 13. The adhesive is not particularly limited, but is preferably one that has high transmittance, high light resistance, and high heat resistance for the white light WL. For example, transparent adhesives include silicone adhesives, ultraviolet curing adhesives, and heat curing adhesives. In addition, the incident side polarizing element 80 and the wavelength conversion element 13 may not be bonded to each other, but may be overlapped in the Z direction and chemically or physically integrated. In a method of chemically overlapping the incident side polarizing element 80 and the wavelength conversion element 13, for example, the polarizing plate 82 and the phosphor layer 14 may be overlapped in the Z direction and cooled. In a method of physically overlapping the incident-side polarizing element 80 and the wavelength conversion element 13, for example, the polarizing plate 82 and the phosphor layer 14 may be overlapped in the Z direction and at least a part of the periphery may be fixed with a fixing member (not shown).

[0043] According to the projector of the second embodiment, the same action and effect as the projector 101 of the first embodiment can be obtained. Furthermore, in the projector of the second embodiment, the incident-side polarizing element 80 abuts against the wavelength conversion element 13 of the light-emitting unit 10, and therefore the amount of white light WL reflected from the incident-side polarizing element 80 and incident on the wavelength conversion element 13 can be further increased compared to the first embodiment in which the incident-side polarizing element 80 is disposed at an interval from the wavelength conversion element 13.

[0044] [Third embodiment] Next, a third embodiment of the present invention will be described with reference to Fig. 4. Although not shown, the projector of the third embodiment includes a light-emitting unit 10, an incident-side polarizing element 80, a pickup lens 30, a collimating lens 35, a light modulation element 40, an exit-side polarizing element 50, and a projection optical system 70, similar to the projector 101 of the first embodiment.

[0045] FIG. 4 is a schematic diagram for explaining the configuration of the light-emitting unit 10 and the incident-side polarizing element 80 of the third embodiment and the behavior of light. As shown in FIG. 4, in the projector of the third embodiment, a wire grid polarizer 84 is used as the incident-side polarizing element 80. The wire grid polarizer 84 has, for example, a base material 87 and a plurality of line members 88. The base material 87 has an incident-side plate surface 87a and an exit-side plate surface 87b parallel to the light-emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13. The base material 87 is formed of a material having high transmittance and heat dissipation for white light WL, and is formed of, for example, optical glass, quartz (SiO2), sapphire with excellent heat dissipation, or an organic material. The plurality of line members 88 are provided at intervals from each other on the plate surface 87b of the base material 87 and are made of metal.

[0046] As in the first embodiment, when the predetermined polarization direction is parallel to the Y direction, each line member 88 extends in the X direction. The multiple line members 88 are arranged at intervals d from each other in the Y direction. The interval d is the distance between the centers of adjacent line members 88 in the Y direction. It is preferable that the period of the multiple line members 88 is smaller than half the peak wavelength of the blue light BL based on the interval d. The peak wavelength of the blue light BL corresponds to the "predetermined wavelength of the first light" described in the claims below.

[0047] According to the projector of the third embodiment, the same effects as those of the projector 101 of the first embodiment can be obtained. Furthermore, in the projector of the third embodiment, since the incident-side polarizing element 80 is configured by the wire grid polarizer 84, heat from the phosphor layer 14 of the wavelength conversion element 13 of the light-emitting section 10 is received by the base material 87 via a plurality of metal line members 88 or directly, and dissipated from the base material 87. By dissipating the heat of the wavelength conversion element 13 via the incident-side polarizing element 80 in this manner, the heat dissipation performance of the projector of the third embodiment can be improved.

[0048] [Fourth embodiment] Next, a fourth embodiment of the present invention will be described with reference to Fig. 5. Although not shown, the projector of the fourth embodiment includes a light-emitting unit 10, an incident-side polarizing element 80, a pickup lens 30, a collimating lens 35, a light modulation element 40, an exit-side polarizing element 50, and a projection optical system 70, similar to the projector 101 of the first embodiment.

[0049] FIG. 5 is a schematic diagram for explaining the configuration and light behavior of the light-emitting unit 10 and the incident-side polarizing element 80 of the fourth embodiment. As shown in FIG. 5, in the projector of the fourth embodiment, the light-emitting unit 10 is composed of a substrate 11, a light source 12, a wavelength conversion element 13, and a dichroic mirror 16. The dichroic mirror 16 is disposed on the optical path of the blue light BL between the multiple light sources 12 and the phosphor layer 14 which is the wavelength conversion element 13. The incident surface 16a of the dichroic mirror 16 facing the multiple light sources 12 and the light-emitting surfaces 12s of the multiple light sources 12 are disposed at an interval from each other in the Z direction. The phosphor layer 14 is provided on the exit surface 16b of the dichroic mirror 16 on the opposite side to the incident surface 16a. That is, the incident surface 14a of the phosphor layer 14 is in contact with the exit surface 16b of the dichroic mirror 16. The incident-side polarizing element 80 is provided on the light-emitting surface 14s of the phosphor layer 14. That is, the incident surface 82 a of the polarizing plate 82 of the incident-side polarizing element 80 abuts on the light-emitting surface 14 s of the phosphor layer 14 of the wavelength conversion element 13 .

[0050] In the first embodiment, the behavior of the yellow light YL emitted radially from the light-emitting surface 14s of the phosphor layer 14 toward the incident-side polarizing element 80 has been described with emphasis on FIG. 2. However, the phosphor layer 14 emits the yellow light YL in all directions using the blue light BL emitted from the multiple light sources 12 as excitation light. That is, the phosphor layer 14 also emits the yellow light YL toward the light source 12. In the fourth embodiment, the dichroic mirror 16 transmits the blue light BL including the blue light BL1 emitted from the light source 12, and reflects the yellow light YL6 emitted toward the light source 12 out of the yellow light YL emitted from the phosphor layer 14. The yellow light YL6 corresponds to "at least a part of the second light" described in the claims below. At least a part of the yellow light YL7 reflected by the dichroic mirror 16 transmits through the phosphor layer 14, travels along the same optical path as the yellow light YL1 described in the first embodiment, and behaves in the same manner as the yellow light YL1. The remainder of the yellow light YL 7 reflected by the dichroic mirror 16 is internally scattered in the phosphor layer 14 .

[0051] The dichroic mirror 16 reflects the yellow light YL3 having a polarization direction other than the predetermined polarization direction that has been reflected by the incident-side polarizing element 80 and transmitted through the phosphor layer 14. The yellow light YL8 reflected by the dichroic mirror 16 travels along the same optical path as the above-mentioned yellow light YL7. The dichroic mirror 16 reflects the incident yellow light YL including the yellow light YL3 and YL6.

[0052] According to the projector of the fourth embodiment, the same action and effect as the projector 101 of the first embodiment can be obtained. Moreover, the projector of the fourth embodiment further includes a dichroic mirror 16 arranged between the light source 12 and the wavelength conversion element 13. The dichroic mirror 16 transmits the blue light BL and reflects at least a part of the yellow light YL. According to the projector of the fourth embodiment, the yellow light YL reflected by the incident-side polarizing element 80 and transmitted through the wavelength conversion element 13 is reflected by the dichroic mirror 16, so that the utilization efficiency of the yellow light YL can be improved.

[0053] Furthermore, in the projector of the fourth embodiment, as in the projector of the second embodiment, the incident side polarizing element 80 abuts the wavelength conversion element 13 of the light-emitting section 10, so that the amount of white light WL reflected from the incident side polarizing element 80 and incident on the wavelength conversion element 13 can be increased compared to the projector 101 of the first embodiment.

[0054] As a modification of the fourth embodiment, a light-transmitting member 18 may be provided on the incident surface 16a of the dichroic mirror 16 of the light-emitting unit 10, as shown by a dashed line in Fig. 5. The light-transmitting member 18 has an incident surface 18a and an exit surface 18b parallel to the incident surface 16a of the dichroic mirror 16. In other words, the exit surface 18b of the light-transmitting member 18 abuts against the incident surface 16a of the dichroic mirror 16. The incident surface 18a of the light-transmitting member 18 is disposed at a distance from the light-emitting surfaces 12s of the multiple light sources 12 in the Z direction.

[0055] The light-transmitting member 18 plays a role of supporting the dichroic mirror 16, the phosphor layer 14 of the wavelength conversion element 13, and the incident-side polarizing element 80. That is, the light-transmitting member 18 is a support member for the dichroic mirror 16. In particular, the size, i.e., thickness, of the dichroic mirror 16 in the Z direction is, for example, about 0.1 mm, which is thinner than the phosphor layer 14 and the incident-side polarizing element 80. Therefore, by providing the light-transmitting member 18, at least the dichroic mirror 16 is stably disposed. For example, the dichroic mirror 16 may be formed by evaporating powder of the material of the dichroic mirror 16 onto the exit surface 18b of the light-transmitting member 18.

[0056] The light-transmitting member 18 is formed of a material that transmits at least the blue light BL and is formed of a material that is transmissive to light in the visible wavelength band including the blue light BL and the yellow light YL. The light-transmitting member 18 is formed of, for example, optical glass, quartz, or the like, and may be formed of sapphire that has excellent heat dissipation properties. In other words, by using a material that is transmissive to at least the blue light BL and has high heat dissipation properties as the light-transmitting member 18, it is possible to improve the heat dissipation properties of the light-emitting section in the projector of the modified example of the fourth embodiment.

[0057] In the modification of the fourth embodiment, the dichroic mirror 16 and the light-transmitting member 18 shown in Fig. 5 may be arranged in a reversed manner. That is, the dichroic mirror 16 may be provided on the incident surface 18a of the light-transmitting member 18, and the exit surface 18b of the light-transmitting member 18 and the incident surface 14a of the phosphor layer 14 of the wavelength conversion element 13 may be in contact with each other. In this case, the light-transmitting member 18 is transmissive to at least the blue light BL and the yellow light YL. Even with such a configuration, it is possible to obtain the same effect as the modification of the fourth embodiment described above.

[0058] [Fifth embodiment] Next, a fifth embodiment of the present invention will be described with reference to Fig. 6. Although not shown, the projector of the fifth embodiment includes a light-emitting unit 10, an incident-side polarizing element 80, a pickup lens 30, a collimating lens 35, a light modulation element 40, an exit-side polarizing element 50, and a projection optical system 70, similar to the projector 101 of the first embodiment.

[0059] FIG. 6 is a schematic diagram for explaining the configurations of the light-emitting unit 10, the incident-side polarizing element 80, and the pickup lens 30 of the fifth embodiment and the behavior of light. As shown in FIG. 6, in the projector of the fifth embodiment, the incident-side polarizing element 80 includes a base material 85 and a reflective polarizing layer 86. The base material 85 is formed to be larger than the phosphor layer 14 of the wavelength conversion element 13 of the light-emitting unit 10 in the XY plane. The base material 85 is formed in a hemispherical or dome shape, and has a convex curved surface that is convex so as to move away from the phosphor layer 14 as it approaches the center from the periphery when viewed along the Z direction. The base material 85 has a convex curved surface 85a onto which the white light WL emitted from the phosphor layer 14 is incident, and a convex curved surface 85b from which the white light WL transmitted through the base material 85 is emitted. The base material 85 is formed of a material that is translucent to light in the visible wavelength band of the white light WL, and is formed of, for example, optical glass, quartz, sapphire, or the like. The base material 85 may be a film-like base material that can retain its shape.

[0060] The reflective polarizing layer 86 is provided on the convex curved surface 85a of the substrate 85. The polarizing layer 86 is supported by the substrate 85, and is arranged to be smaller than the substrate 85 in the XY plane and slightly larger than the phosphor layer 14 of the wavelength conversion element 13, and surrounds and covers the phosphor layer 14. The polarizing layer 86 has an incident surface 86a facing the light emitting surface 14s of the phosphor layer 14 and an exit surface 86b on the opposite side to the incident surface 86a. The exit surface 86b of the polarizing layer 86 abuts against the convex curved surface 85a of the substrate 85. The polarizing layer 86 transmits polarized light of a predetermined polarization direction out of the white light WL emitted from the light emitting unit 10, and reflects polarized light of a direction other than the predetermined polarization direction, like the polarizing plate 82. The polarizing layer 86 has sensitivity to the visible wavelength band.

[0061] The pickup lens 30 of the fifth embodiment is disposed on the optical path of the white light WL having a predetermined polarization direction that has passed through the incident-side polarizing element 80, and is disposed on the optical path of the white light WL between the incident-side polarizing element 80 and a collimating lens 35 (not shown in Fig. 6). The pickup lens 30 is a biconvex lens 21. The biconvex lens 21 has a convex curved surface that is convex on both the incident side and the exit side of the white light WL that is emitted from the incident-side polarizing element 80 and enters the biconvex lens 21.

[0062] The yellow light YL1 emitted radially from the wave source WS1 at an arbitrary position on the light emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13 of the light emitting unit 10 is incident on the polarizing layer 86 from the incident surface 86a. The yellow light YL2 having a predetermined polarization direction among the white light WL incident on the polarizing layer 86 is transmitted through the polarizing layer 86 and the base material 85, and is incident on the pickup lens 30. The yellow light YL3 having a polarization direction other than the predetermined polarization direction among the white light WL incident on the polarizing layer 86 is reflected by the polarizing layer 86, and is irradiated at a position close to the wave source WS1 on the light emitting surface 14s of the phosphor layer 14. The position close to the wave source WS1 on the light emitting surface 14s means a position whose distance from the wave source WS1 is shorter than the distance in the XY plane between the wave source WS1 and the position where the yellow light YL1 is irradiated on the incident surface 86a of the polarizing layer 86. Although not shown, the blue light BL1 emitted from the light emitting surfaces 12s of the multiple light sources 12 also travels along the same optical path as the yellow light YL1 described above.

[0063] The yellow light YL3 irradiated from the polarizing layer 86 of the incident-side polarizing element 80 to a position close to the wave source WS1 on the light-emitting surface 14s of the phosphor layer 14 is internally scattered by the phosphor layer 14. The blue light BL3 irradiated from the polarizing layer 86 to a position substantially similar to the yellow light YL3 on the light-emitting surface 14s of the phosphor layer 14 acts as excitation light in the phosphor layer 14 and re-excites the phosphor layer 14. As a result, the yellow light YL4 is emitted from a position substantially similar to the wave source WS1. The yellow light YL4 again enters the polarizing layer 86. The polarized light of a predetermined polarization direction of the yellow light YL4 that entered the polarizing layer 86 passes through the polarizing layer 86 and the base material 85 and enters the pickup lens 30. The yellow light YL10 of a polarization direction other than the predetermined polarization direction of the yellow light YL4 that entered the polarizing layer 86 is reflected by the polarizing layer 86 and is irradiated to a position near the wave source WS1 on the light-emitting surface 14s of the phosphor layer 14.

[0064] As described above, since the incident-side polarizing element 80 covers the light-emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13 in a dome shape, the yellow light YL and the blue light BL reflected by the incident-side polarizing element 80 toward the phosphor layer 14 are irradiated to a position close to the wave source WS1 on the light-emitting surface 14s of the phosphor layer 14. As a result, the white light WL reflected by the incident-side polarizing element 80 and having a polarization direction other than the predetermined polarization direction is concentrated at a position close to the wave source WS1 on the light-emitting surface 14s of the phosphor layer 14.

[0065] According to the projector of the fifth embodiment, the same effect as the projector 101 of the first embodiment can be obtained. In addition, in the projector of the fifth embodiment, the incident side polarizing element 80 is provided in a dome shape so as to cover the light emitting surface 14s on the opposite side to the incident surface 14a facing the light source 12 in the phosphor layer 14 of the wavelength conversion element 13 of the light emitting unit 10. As a result, compared to the case where the light emitting surface of the wavelength conversion element 13 and the incident surface and the exit surface of the incident side polarizing element 80 are parallel to each other as exemplified in the first embodiment, the white light WL reflected by the incident side polarizing element 80 to the outside of the wavelength conversion element 13 in the XY plane and lost can be reduced, and the white light WL reflected by the reflective incident side polarizing element 80 after being emitted from the wavelength conversion element 13 can be irradiated more onto the light emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13. As a result, the light utilization efficiency in the projector of the fifth embodiment can be improved.

[0066] Although not shown, as a modification of the fifth embodiment, a dichroic mirror acting similarly to the dichroic mirror 16 described in the fourth embodiment may be provided between the plurality of light sources 12 and the wavelength conversion element 13. In that case, the yellow light YL reflected by the incident-side polarizing element 80 and transmitted through the wavelength conversion element 13 is reflected by the dichroic mirror, so that the utilization efficiency of the yellow light YL can be improved. In addition, in the above-mentioned configuration, a translucent member acting similarly to the translucent member 18 described in the fourth embodiment may be provided between the plurality of light sources 12 and the dichroic mirror, or between the dichroic mirror and the wavelength conversion element 13. This allows the dichroic mirror to be stably arranged.

[0067] [Sixth embodiment] Next, a sixth embodiment of the present invention will be described with reference to Fig. 7. Although not shown, the projector of the sixth embodiment includes a light emitting unit 10, a pickup lens 30, an entrance side polarizing element 80, a collimating lens 35, a light modulation element 40, an exit side polarizing element 50, and a projection optical system 70, similar to the projector 101 of the first embodiment.

[0068] 7 is a schematic diagram for explaining the configurations and light behavior of the light-emitting unit 10, the pickup lens 30, and the incident-side polarizing element 80 of the sixth embodiment. As shown in FIG. 7, in the light-emitting unit 10 of the sixth embodiment, the incident-side polarizing element 80 is provided on the light-emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13 of the light-emitting unit 10, similarly to the light-emitting unit 10 of the second embodiment. That is, the incident surface 82a of the polarizing plate 82 of the incident-side polarizing element 80 abuts against the light-emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13.

[0069] The pickup lens 30 of the sixth embodiment is disposed on the optical path of the white light WL including the yellow light YL and the blue light BL emitted from the wavelength conversion element 13 of the light emitting unit 10, and is disposed on the optical path of the white light WL between the wavelength conversion element 13 and the incident-side polarizing element 80. The pickup lens 30 is composed of a plano-convex lens 33A and a biconvex lens 33B. The plano-convex lens 33A has a plane parallel to the XY plane and a convex curved surface that is convex on the emission side of the white light WL that is emitted from the wavelength conversion element 13 and enters the plano-convex lens 33A. The biconvex lens 33B has convex curved surfaces that are convex on the entrance side and the emission side of the white light WL that is emitted from the plano-convex lens 33A and enters the biconvex lens 33B.

[0070] The incident-side polarizing element 80 of the sixth embodiment is arranged on the optical path of the white light WL emitted from the pickup lens 30, and is arranged on the optical path of the white light WL between the wavelength conversion element 13 and the parallelizing lens 35 not shown in Figure 6.

[0071] The white light WL diffused and emitted from the light emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13 of the light emitting unit 10 is incident on the plano-convex lens 33A of the pickup lens 30. The plano-convex lens 33A expands the incident white light WL in the XY plane according to the shape of the convex curved surface, etc., and emits it from the convex curved surface. The white light WL emitted from the plano-convex lens 33A is incident on the biconvex lens 33B. The biconvex lens 33B further expands the incident white light WL in the XY plane according to the shape of the convex curved surface, etc., and emits it from the convex curved surface on the emission side.

[0072] The white light WL emitted from the pickup lens 30 is incident on the polarizing plate 82 of the incident side polarizing element 80. Of the white light WL incident on the incident side polarizing element 80, polarized light having a predetermined polarization direction is transmitted through the incident side polarizing element 80 and emitted from the incident side polarizing element 80 toward the parallelizing lens 35 (not shown). Of the white light WL incident on the incident side polarizing element 80, polarized light having a direction other than the predetermined polarization direction is reflected by the incident side polarizing element 80, passes through the pickup lens 30, is reduced in the XY plane, and is incident on the wavelength conversion element 13 from the light emitting surface 14s of the phosphor layer 14. The white light WL having a direction other than the predetermined polarization direction reflected by the incident side polarizing element 80 travels in the opposite direction along an optical path that is substantially the same as the optical path of the white light WL from the light emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13 to the incident surface 82a of the polarizing plate 82 of the incident side polarizing element 80.

[0073] As described in the above embodiments, the yellow light YL of the white light WL reflected by the incident-side polarizing element 80 and incident on the wavelength conversion element 13 is internally scattered in the phosphor layer 14, and a part of the yellow light YL is emitted from the wavelength conversion element 13 toward the pickup lens 30. The blue light BL of the white light WL reflected by the incident-side polarizing element 80 and incident on the wavelength conversion element 13 acts as excitation light in the phosphor layer 14, and the yellow light YL generated by re-excitation is also emitted from the wavelength conversion element 13 toward the pickup lens 30.

[0074] The projector of the sixth embodiment provides the same effects as the projector 101 of the first embodiment. In addition, in the projector of the sixth embodiment, the incident-side polarizing element 80 is disposed on the optical path of the white light WL between the pickup lens 30 and the collimating lens 35. According to the projector of the sixth embodiment, it is easier to secure a wide space for installing the incident-side polarizing element 80 than in the case where the incident-side polarizing element 80 is disposed on the optical path of the white light WL between the wavelength conversion element 13 of the light-emitting unit 10 and the pickup lens 30 as in the projector of the first embodiment, and it is easier to install the incident-side polarizing element 80 and a support member for the incident-side polarizing element 80 (not shown), etc.

[0075] Furthermore, in the projector of the sixth embodiment, like the projector of the second embodiment, the incident side polarizing element 80 abuts the wavelength conversion element 13 of the light-emitting section 10, so that the amount of white light WL reflected from the incident side polarizing element 80 and incident on the wavelength conversion element 13 can be increased compared to the projector 101 of the first embodiment.

[0076] [Seventh embodiment] Next, a seventh embodiment of the present invention will be described with reference to Fig. 8. Although not shown, the projector of the seventh embodiment includes a light emitting unit 10, a pickup lens 30, an entrance side polarizing element 80, a collimating lens 35, a light modulation element 40, an exit side polarizing element 50, and a projection optical system 70, similar to the projector of the sixth embodiment.

[0077] FIG. 8 is a schematic diagram for explaining the configuration and light behavior of the light-emitting unit 10, the pickup lens 30, and the incident-side polarizing element 80 of the seventh embodiment. As shown in FIG. 8, the light-emitting unit 10 of the seventh embodiment is composed of a substrate 11, a light source 12, a wavelength conversion element 13, a dichroic mirror 16, and a light-transmitting member 18, similar to the light-emitting unit 10 of the modified fourth embodiment. That is, the incident surface 14a of the phosphor layer 14 of the wavelength conversion element 13 is disposed at an interval in the Z direction from the light-emitting surfaces 12s of the multiple light sources 12. The dichroic mirror 16 and the light-transmitting member 18 are disposed on the optical path of the white light WL between the multiple light sources 12 and the wavelength conversion element 13. The incident surface 18a of the light-transmitting member 18 is disposed at an interval in the Z direction from the light-emitting surfaces 12s of the multiple light sources 12. The dichroic mirror 16 is provided on the exit surface 18b of the light-transmitting member 18. The incident-side polarizing element 80 is provided on the exit surface 16b of the dichroic mirror 16. The exit surface 18b of the light-transmitting member 18 and the entrance surface 16a of the dichroic mirror 16 abut against each other, and the exit surface 16b of the dichroic mirror 16 and the entrance surface 14a of the phosphor layer 14 abut against each other.

[0078] The projector of the seventh embodiment has the same effects as the projector of the sixth embodiment. In the projector of the seventh embodiment, the light source 12 and the wavelength conversion element 13 are Since the dichroic mirror 16 is disposed between the incident side polarizing element 80 and the The yellow light YL that is reflected by the wavelength conversion element 13 and transmitted through the wavelength conversion element 13 is directed to the dichroic mirror 16. Therefore, the utilization efficiency of the yellow light YL and 7 Light utilization in the projector of the embodiment In addition, in the projector according to the seventh embodiment, the dichroic A light-transmitting member 18 is provided on the incident surface 16a of the mirror 16, thereby forming a dichroic The mirror 16 and the phosphor layer 14 are stably arranged. The seventh embodiment uses a material that is transparent to the color light BL and has high heat dissipation properties. This can improve the heat dissipation performance of the light-emitting unit 10 in the projector in this embodiment.

[0079] [Eighth embodiment] Next, an eighth embodiment of the present invention will be described with reference to Fig. 9. Although not shown, the projector of the eighth embodiment includes a light-emitting unit 10, a pickup lens 30, an entrance-side polarizing element 80, a collimating lens 35, a light modulation element 40, an exit-side polarizing element 50, and a projection optical system 70, like the projector of the sixth embodiment, and further includes a retardation plate 90.

[0080] FIG. 9 is a schematic diagram for explaining the configuration and light behavior of the light emitting unit 10, the pickup lens 30, the retardation plate 90, and the incident-side polarizing element 80 of the eighth embodiment. As shown in FIG. 9, the retardation plate 90 is disposed on the optical path of the white light WL between the biconvex lens 33B of the pickup lens 30 and the polarizing plate 82 of the incident-side polarizing element 80. The retardation plate 90 is not particularly limited as long as it is a member capable of imparting a predetermined phase difference to the nonlinearly polarized white light WL emitted from the biconvex lens 33B, but is preferably, for example, a quarter-wave plate. In the eighth embodiment, the retardation plate 90 will be described assuming that it is a quarter-wave plate 92.

[0081] The white light WL emitted from the pickup lens 30 enters the retardation plate 90 before entering the incident-side polarizing element 80. The retardation plate 90 imparts a predetermined phase difference to the incident white light WL and converts the white light WL into polarized light having a polarization direction according to the phase difference. Since the retardation plate 90 is a quarter-wave plate 92, the predetermined phase difference is ¼ of the incident wavelength, i.e., π / 2. For example, when P-polarized or S-polarized white light WL enters the quarter-wave plate 92 of the retardation plate 90, the quarter-wave plate 92 converts the incident white light WL into elliptically polarized or circularly polarized white light WL and emits the elliptically polarized or circularly polarized white light WL.

[0082] When the degree of randomness of the nonlinearly polarized blue light BL emitted from the multiple light sources 12 in the light-emitting unit 10 is high, and the polarization conversion function of the phosphor layer 14 of the wavelength conversion element 13 is low, and the degree of randomness of the white light WL emitted from the phosphor layer 14 is high like the blue light BL and yellow light YL incident on the phosphor layer 14, first, the nonlinearly polarized white light WL with a high degree of randomness is incident on the quarter-wave plate 92 of the retardation plate 90 from the incident surface 92a, and a phase difference of π / 2 is given to the white light WL. The quarter-wave plate 92 emits linearly polarized white light WL. In this case, it is preferable that the leading axis or the lagging axis (not shown) of the quarter-wave plate 92 is appropriately arranged so that the polarization direction of most of the linearly polarized white light WL emitted from the quarter-wave plate 92 is approximately equivalent to the predetermined polarization direction of the light transmitted by the polarizing plate 82 of the incident-side polarizing element 80. This increases the amount of white light WL having a predetermined polarization direction that is transmitted through the incident-side polarizing element 80.

[0083] When the white light WL emitted from the quarter-wave plate 92 enters the polarizing plate 82 of the entrance-side polarizing element 80, the polarized light having a predetermined polarization direction out of the incident white light WL passes through the polarizing plate 82 and is emitted toward the collimating lens 35 (not shown in FIG. 9 ). The polarized light having a direction other than the predetermined polarization direction out of the white light WL incident on the polarizing plate 82 is reflected by the polarizing plate 82 and enters the quarter-wave plate 92.

[0084] The white light WLO2 reflected by the polarizing plate 82 and incident on the quarter-wave plate 92 passes through the quarter-wave plate 92, and a phase difference of π / 2 is given to the white light WLO2. For example, if most of the white light WLO2 is linearly polarized light perpendicular to a predetermined polarization direction in the XY plane, the white light WLO2 is converted by the quarter-wave plate 92 into circularly polarized light including elliptically polarized light. The quarter-wave plate 92 emits white light WL according to the polarization state of the white light WLO2 reflected by the polarizing plate 82, that is, the white light WL after a phase difference of π / 2 is given to the white light WLO2 reflected by the polarizing plate 82, toward the pickup lens 30. The white light WL emitted from the quarter-wave plate 92 toward the pickup lens 30 travels in the opposite direction along an optical path substantially similar to that of the white light WL that passes from the wavelength conversion element 13 through the pickup lens 30 and enters the quarter-wave plate 92, is reduced in the XY plane by the pickup lens 30, and enters the phosphor layer 14 of the wavelength conversion element 13 from the light-emitting surface 14s.

[0085] As described in each of the above embodiments, the blue light BL of the white light WL incident on the phosphor layer 14 from the light-emitting surface 14s acts as excitation light, generating yellow light YL. The yellow light YL of the white light WL incident on the phosphor layer 14 from the light-emitting surface 14s is internally scattered in the phosphor layer 14. Since the polarization conversion function of the phosphor layer 14 is low as described above, the polarization state of the white light WL emitted from the light-emitting surface 14s of the phosphor layer 14 to the pickup lens 30 due to the white light WLO2 is substantially similar to the polarization state of the white light WL incident on the phosphor layer 14 due to the white light WLO2.

[0086] The white light WL emitted from the phosphor layer 14 to the pickup lens 30 due to the white light WLO2 passes through the pickup lens 30 and enters the quarter-wave plate 92. A phase difference of π / 2 is given to the white light WL incident on the quarter-wave plate 92. After that, the white light WL emitted from the quarter-wave plate 92 enters the polarizing plate 82 of the incident-side polarizing element 80. The polarized light of the incident white light WL in a predetermined polarization direction is transmitted through the polarizing plate 82, and the polarized light other than the predetermined polarization direction is reflected by the polarizing plate 82. For example, if most of the white light WLO2 is linearly polarized light perpendicular to the predetermined polarization direction in the XY plane, the white light WL emitted from the phosphor layer 14 due to the white light WLO2 and incident on the quarter-wave plate 92 is converted into linearly polarized light in the predetermined polarization direction by the quarter-wave plate 92. Most of the white light WL converted into linearly polarized light in the predetermined polarization direction by the quarter-wave plate 92 in this way passes through the polarizing plate 82.

[0087] The white light WLO4 having a polarization direction other than the specified direction that is reflected a second time by the polarizing plate 82 travels on an optical path at a different position in the XY plane from the white light WLO2, in the Z direction in the same manner as the white light WLO2 and the white light WL resulting from the white light WLO2.

[0088] 10 is a graph showing an example of the effective utilization efficiency of the yellow light YL and blue light BL contained in each of the first to sixth white light WL in the projector of any one of the first to eighth embodiments, calculated by a numerical simulation. The effective utilization efficiency of the first yellow light YL and blue light BL represents the effective utilization efficiency of the yellow light YL and blue light BL that are transmitted through the incident side polarizing element 80 for the first time, i.e., the first time. The effective utilization efficiency of each of the second to sixth yellow light YL and blue light BL represents the effective utilization efficiency of the yellow light YL and blue light BL that are reflected by the incident side polarizing element 80 and then transmitted through the incident side polarizing element 80 for the second to sixth times. For reference, Figure 10 shows the results of calculating the effective utilization efficiency of the blue light BL and yellow light YL contained in each of the white lights WL from the first order white light WLO1 to the sixth order white light WLO6, assuming a configuration in which the incident side polarizing element 80 is not positioned on the optical path of the white light WL downstream of the light-emitting section 10 in the projectors of the first to eighth embodiments.

[0089] "With reflective polarizer immediately after light source" in FIG. 10 shows the calculation result in a configuration in which an incident side polarizing element 80 is provided like the projectors of the first to eighth embodiments. "Without reflective polarizer immediately after light source" in FIG. 10 shows the calculation result in a reference example configuration in which an incident side polarizing element 80 is not provided. Note that "immediately after light source" in FIG. 10 means the rear stage of the light source 12 via the phosphor layer 14 which is the wavelength conversion element 13 and the front stage of components other than the wavelength conversion element 13, such as the pickup lens 30. In addition, in both cases of "With reflective polarizer immediately after light source" and "Without reflective polarizer immediately after light source" in FIG. 10, it was assumed that an absorptive polarizing element was disposed between the collimating lens 35 and the liquid crystal element 43 as described in the first embodiment. Specifically, in this calculation, a wire grid polarizer 84 was used as the incident side polarizing element 80, and the reflection axis of the wire grid polarizer 84 was aligned with the absorption axis of an absorptive polarizing element not shown.

[0090] As shown in FIG. 10, the effective utilization efficiency of the first-order yellow light YL is higher than that of the second-order or higher-order yellow light YL. In a projector provided with an incident-side polarizing element 80, a reflective polarizing plate 82 or a wire grid polarizer 84 is disposed as the incident-side polarizing element 80 on the optical path of the white light WL immediately after the light-emitting unit 10, so that a larger amount of the white light WL reflected by the incident-side polarizing element 80 returns to the light-emitting unit 10, enters the wavelength conversion element 13, and is internally scattered. As a result, the effective utilization efficiency of the second-order yellow light YL is lower than that of the first-order yellow light YL, but is still obtainable to a certain extent. As the order increases, the effective utilization efficiency of the yellow light YL decreases, but the effective utilization efficiency of the yellow light YL decreases approximately quadratically, and for example, the second-order to fifth-order yellow light YL can be effectively utilized in the light modulation element 40 disposed after the incident-side polarizing element 80.

[0091] On the other hand, in the reference example in which the incident side polarizing element 80 is not provided, the effective utilization efficiency of the first-order yellow light YL is higher by the amount of the light loss in the incident side polarizing element 80 compared to the configuration of the projector in which the incident side polarizing element 80 is provided. However, in the reference example in which the incident side polarizing element 80 is not provided, a part of the polarized light of the white light WL is absorbed by the absorption type polarizing plate arranged between the parallelizing lens 35 and the liquid crystal element 43, and at least the white light WL does not return to the light emitting unit 10 and does not enter the wavelength conversion element 13. As a result, the effective utilization efficiency of the second-order yellow light YL is approximately 0%. That is, in the reference example in which the incident side polarizing element 80 is not provided, the second-order or higher-order yellow light YL is not effectively utilized in the light modulation element 40. In the reference example in which the incident side polarizing element 80 is not provided, when integrated over all orders, it can be seen that the effective utilization efficiency of the yellow light YL is lower than the configuration of the projector in which the incident side polarizing element 80 is provided as described in the first to eighth embodiments.

[0092] As described in the first embodiment, in the case of white light WL having a chromaticity that is normally used, the amount of blue light BL emitted from the light source 12 and transmitted through the wavelength conversion element 13 is relatively smaller than the amount of yellow light YL emitted from the wavelength conversion element 13. Therefore, the effective utilization efficiency of the first-order blue light BL is lower than the effective utilization efficiency of the first-order yellow light YL. However, in the case of higher orders of the second order or higher, the change in the effective utilization efficiency of the blue light BL with an increase in the order is similar to the change in the effective utilization efficiency of the yellow light YL. That is, in a projector provided with an entrance-side polarizing element 80, the effective utilization efficiency of the blue light BL decreases as the order increases, but the effective utilization efficiency of the blue light BL decreases approximately quadratically, and for example, the second to fourth orders of blue light BL can be effectively utilized in the light modulation element 40 arranged in the rear stage of the entrance-side polarizing element 80. On the other hand, in the reference example in which the entrance-side polarizing element 80 is not provided, the second or higher order blue light BL is not effectively utilized in the light modulation element 40. In the reference example in which the incident-side polarizing element 80 is not provided, it can be seen that the effective utilization efficiency of the blue light BL is also lower when integrated over all orders, compared to the configuration of the projector in which the incident-side polarizing element 80 is provided. Note that in this calculation, a wire grid polarizer 84 was assumed as the incident-side polarizing element 80, but similar results can be obtained even if a polarizing plate 82 is used as the incident-side polarizing element 80 as described in the above-mentioned embodiments. In other words, the effects confirmed by this calculation are common whether the incident-side polarizing element 80 is the polarizing plate 82 or the wire grid polarizer 84, and can be said to be effects commonly exhibited by the projectors of the first to eighth embodiments.

[0093] The projector of the eighth embodiment described above provides the same effects as the projector of the sixth embodiment. The projector of the eighth embodiment further includes a retardation plate 90 disposed between the wavelength conversion element 13 and the incident-side polarizing element 80. The retardation plate 90 provides a predetermined phase difference to the incident white light WL. According to the projector of the eighth embodiment, the phase of the light emitted from the wavelength conversion element 13 due to the light reflected by the incident-side polarizing element 80 is modulated by the retardation plate 90, so that a significant decrease in the effective utilization efficiency, i.e., the transmittance, of the blue light BL and the yellow light YL at the incident-side polarizing element 80 can be suppressed.

[0094] In the projector of the eighth embodiment, the retardation plate 90 is a quarter-wave plate 92. In the projector of the eighth embodiment, a phase difference of 1 / 4 of the emission wavelength, that is, π / 2, is given to the blue light BL and yellow light YL contained in the white light WL reflected by the incident-side polarizing element 80 and having a polarization direction perpendicular to a predetermined polarization direction in the XY plane. A phase difference of π / 2 is also given by the incident-side polarizing element 80 to the white light WL emitted from the wavelength conversion element 13 due to the white light WL having a polarization direction perpendicular to the predetermined polarization direction. According to the projector of the eighth embodiment, the incident-side polarizing element 80 converts the white light WL emitted from the wavelength conversion element 13 due to the white light WL having a polarization direction perpendicular to the predetermined polarization direction into polarized light with a predetermined polarization direction, and the white light WL can be transmitted through the incident-side polarizing element 80. That is, according to the projector of the eighth embodiment, since the quarter-wave plate 92 is used as the retardation plate 90, a significant decrease in the effective utilization efficiency, that is, the transmittance, of the blue light BL and yellow light YL at the incident-side polarizing element 80 can be suitably suppressed.

[0095] Although it has been described that the quarter-wave plate 92 is preferable as the retardation plate 90, the retardation plate 90 only needs to modulate the phase of the light emitted from the wavelength conversion element 13 due to the light reflected by the incident-side polarizing element 80, even if only a little. If the retardation plate 90 can modulate the phase of the incident light even if only a little, the above-mentioned effect of the projector of the eighth embodiment can be obtained to a great extent. The retardation plate 90 may be, for example, a quartz plate having a predetermined thickness. When the predetermined thickness is determined, the phase difference given to the light according to the wavelength of the light incident on the quartz plate is calculated. Therefore, the predetermined thickness of the quartz plate can be set in consideration of the predetermined phase difference required for the retardation plate 90, the emission wavelength of the blue light BL, and the emission wavelength of the yellow light YL, etc.

[0096] In addition, in the projector of the eighth embodiment, when the polarization conversion function of the wavelength conversion element 13 of the light-emitting unit 10 is low, the effect of suppressing a significant decrease in the transmittance of the blue light BL and the yellow light YL at the incident side polarizing element 80 as described above is prominently exhibited. In the above-mentioned embodiments including the projector of the eighth embodiment, non-linearly polarized blue light BL is emitted from the light source 12 of the light-emitting unit 10. Therefore, for example, when 50% or less of the light incident on the wavelength conversion element 13 is linearly polarized or in a specific polarization state other than non-linearly polarized, preferably when 20% or less of the light incident on the wavelength conversion element 13 is in a specific polarization state other than non-linearly polarized, by adopting the configuration of the projector of the eighth embodiment, a significant decrease in the transmittance of the blue light BL and the yellow light YL at the incident side polarizing element 80 can be reliably suppressed.

[0097] Although not shown, as a modification of the eighth embodiment, the retarder 90 may be in contact with the entrance-side polarizing element 80. Specifically, the exit surface 92b of the quarter-wave plate 92 of the retarder 90 may be in contact with the entrance surface 82a of the polarizing plate 82 of the entrance-side polarizing element 80. According to the projector of the modification of the eighth embodiment, in addition to the above-mentioned effects of the projector of the eighth embodiment, an effect is obtained in that the transmittance of the blue light BL and the yellow light YL at the entrance-side polarizing element 80 can be stabilized.

[0098] [Ninth embodiment] Next, a ninth embodiment of the present invention will be described with reference to Fig. 11. Although not shown, the projector of the ninth embodiment includes a light-emitting unit 10, an incident-side polarizing element 80, a pickup lens 30, a collimating lens 35, a light modulation element 40, an exit-side polarizing element 50, and a projection optical system 70, like the projector of the first embodiment, and further includes a retardation plate 90 and a rod member 200.

[0099] FIG. 11 is a schematic diagram for explaining the configuration and light behavior of the light-emitting unit 10, the retardation plate 90, the incident-side polarizing element 80, and the rod member 200 of the ninth embodiment. As shown in FIG. 11, the retardation plate 90 is disposed on the optical path of the white light WL between the phosphor layer 14 of the wavelength conversion element 13 of the light-emitting unit 10 and the polarizing plate 82 of the incident-side polarizing element 80. The retardation plate 90 is not particularly limited as long as it is a member capable of imparting a phase difference to the nonlinearly polarized white light WL emitted from the wavelength conversion element 13, but is preferably, for example, a quarter-wave plate. As in the eighth embodiment, the retardation plate 90 is, for example, a quarter-wave plate 92.

[0100] The rod member 200 is a member that connects at least the periphery 12r of the entire light sources 12 in the XY plane and the periphery 82r of the polarizing plate 82 of the incident-side polarizing element 80 in the XY plane along the Z direction and the optical path of the white light WL, and is, for example, a cylindrical member. The periphery 12r of the multiple light sources 12 corresponds to the "periphery of the light source" described in the claims described below. Note that, when the light-emitting unit 10 includes one light source 12, the "periphery of the light source" means the periphery of one light source 12. When the light-emitting unit 10 includes multiple light sources 12, the "periphery of the light source" means the periphery of the area occupied by the multiple light sources 12 on the plate surface 11b of the substrate 11.

[0101] The rod member 200 is provided so as to surround at least the plurality of light sources 12 and the incident-side polarizing element 80 in the XY plane. As described in the first embodiment, in the light-emitting unit 10, the blue light BL is radially emitted from each light source 12, so that the phosphor layer 14 of the wavelength conversion element 13 is formed larger than the area occupied by the plurality of light sources 12 on the plate surface 11b of the substrate 11 in the XY plane, and has a size equivalent to that of the substrate 11, for example. In the ninth embodiment, the rod member 200 connects the periphery 11r of the substrate 11 in the XY plane to the periphery 82r of the polarizing plate 82 of the incident-side polarizing element 80 along the optical path of the white light WL. Furthermore, as long as the white light WL does not leak outside the rod member 200 in the XY plane or cause diffuse reflection, etc., the inner wall surface 200w of the rod member 200 may be positioned with a slight gap between the periphery 11r of the substrate 11, the periphery 14r of the phosphor layer 14, and the periphery 82r of the polarizing plate 82.

[0102] As described in the first embodiment, in the light-emitting unit 10, the blue light BL and the yellow light YL are radially emitted from the wavelength conversion element 13, and therefore, in the XY plane, the retardation plate 90 and the incident-side polarizing element 80 are formed larger than the wavelength conversion element 13, and the incident-side polarizing element 80 is formed larger than the retardation plate 90. Therefore, the space surrounded by the inner wall surface 200w of the rod member 200 expands as it progresses along the Z direction from the light source 12 toward the incident-side polarizing element 80. As long as the space surrounded by the inner wall surface 200w is formed to expand as described above, the shape and size of the rod member 200 are not particularly limited.

[0103] The inner wall surface 200w of the rod member 200 reflects the white light WL. Therefore, the rod member 200 may be formed of a material capable of reflecting the white light WL. Alternatively, the rod member 200 may include a base material formed of any material so as to connect the periphery 11r of the substrate 11 and the periphery 82r of the polarizing plate 82 along the optical path of the white light WL as described above, and a reflective film capable of reflecting the white light WL may be provided on the inner wall surface of the base material.

[0104] The white light WL emitted from the wave source WS1 at the outer peripheral portion of the light emitting surface 14s of the phosphor layer 14 of the wavelength conversion element 13 is incident on the retardation plate 90. The retardation plate 90 gives a predetermined phase difference to the incident white light WL. The white light WL emitted from the retardation plate 90 is incident on the incident side polarizing element 80. Of the white light WL incident on the incident side polarizing element 80, polarized light having a predetermined polarization direction is transmitted through the incident side polarizing element 80, and polarized light having a direction other than the predetermined polarization direction is reflected by the incident side polarizing element 80. The polarized light having the predetermined polarization direction transmitted through the incident side polarizing element 80 is incident on the collimating lens 35, not shown in FIG. 11.

[0105] In particular, for the white light WL incident on the incident side polarizing element 80 along a direction diverging outward in the XY plane, polarized light other than the predetermined polarization direction is reflected by the incident side polarizing element 80 and emitted from the incident surface 82a of the polarizing plate 82 of the incident side polarizing element 80 along a direction further diverging in the XY plane. The white light WL emitted along the diverging direction from the incident surface 82a of the polarizing plate 82 in this way is irradiated onto the inner wall surface 200w of the rod member 200 and reflected by the inner wall surface 200w. The white light WL reflected by the inner wall surface 200w is emitted along a direction converging inward in the XY plane, passes through the retardation plate 90, is given a predetermined phase difference, and is polarization-converted. The white light WL polarized and emitted from the retardation plate 90 enters the phosphor layer 14 from the light-emitting surface 14s and is internally scattered. The vicinity of the incident position of the white light WL incident on the phosphor layer 14 from the phase difference plate 90 is set as a wave source WS2, and the white light WL is emitted from the wave source WS2.

[0106] Among the white light WL emitted from the wave source WS2, a part of the white light WL emitted at a wide angle with respect to the Z direction is irradiated to the inner wall surface 200w of the rod member 200 before entering the retardation plate 90, and is reflected by the inner wall surface 200w. The white light WL reflected by the inner wall surface 200w passes through the retardation plate 90, is given a predetermined phase difference, and is polarized and converted. The white light WL that has been polarized and emitted from the retardation plate 90 is incident on the incident side polarizing element 80. Of the white light WL that has entered the incident side polarizing element 80, polarized light with a predetermined polarization direction is transmitted through the incident side polarizing element 80, and polarized light with a direction other than the predetermined polarization direction is reflected by the incident side polarizing element 80. The polarized light with a predetermined polarization direction that has passed through the incident side polarizing element 80 is incident on the parallelizing lens 35, not shown in FIG. 11. The polarized light with a direction other than the predetermined polarization direction that is reflected by the incident side polarizing element 80 behaves in the same manner as described above. At this time, a portion of the white light WL emitted from the incident surface 82a of the polarizing plate 82 in a direction diverging in the XY plane is irradiated onto the inner wall surface 200w of the rod member 200 and is reflected by the inner wall surface 200w. The white light WL reflected by the inner wall surface 200w is emitted in a direction converging in the XY plane, and as a result, is incident on the phosphor layer 14 from the light emitting surface 14s.

[0107] If the white light WL emitted from the outer peripheral portion of the incident surface 82a of the polarizing plate 82 of the incident side polarizing element 80 along the direction diverging in the XY plane, or the white light WL emitted from the wave sources WS1 and WS2 at a wide angle outside the area that can be irradiated on the incident surface 82a of the polarizing plate 82 in the XY plane, is not reflected by the inner wall surface 200w of the rod member 200, it will be emitted to an area outside the light emitting unit 10 and the incident side polarizing element 80. Therefore, by providing the rod member 200, at least a part of the white light WL emitted from the outer peripheral portion of the incident surface 82a of the polarizing plate 82 along the direction diverging, or the white light WL emitted from the wave sources WS1 and WS2 at a wide angle outside the incident surface 82a of the polarizing plate 82 is returned to the wavelength conversion element 13. As a result, at least a part of the white light WL described above is emitted from the exit surface 82b of the polarizing plate 82 of the incident side polarizing element 80 toward the collimating lens 35 and is effectively used.

[0108] The projector of the ninth embodiment described above provides the same effects as the projector of the first embodiment. The projector of the ninth embodiment includes a rod member 200 that connects between the light source 12 and the incident side polarizing element 80. The rod member 200 is provided so as to surround at least the light source 12 and the incident side polarizing element 80. The white light WL irradiated to the inner wall surface 200w of the rod member 200 is reflected by the inner wall surface 200w. According to the projector of the ninth embodiment, the white light WL that diverges in the XY plane in the region between the light source 12 and the wavelength conversion element 13 and the incident side polarizing element 80 is focused using the rod member 200, so that the loss of the white light WL can be suppressed.

[0109] Moreover, in the projector of the ninth embodiment, the retardation plate 90 is a quarter-wave plate 92. According to the projector of the ninth embodiment, the white light WL emitted from the wavelength conversion element 13 due to the white light WL having a polarization direction orthogonal to the predetermined polarization direction by the incident-side polarizing element 80 can be converted into polarized light having a predetermined polarization direction and transmitted through the incident-side polarizing element 80. That is, according to the projector of the ninth embodiment, as with the projector of the eighth embodiment, it is possible to suitably suppress a significant decrease in the effective utilization efficiency, i.e., the transmittance, of the blue light BL and the yellow light YL at the incident-side polarizing element 80.

[0110] Although the preferred retardation plate 90 is the quarter wave plate 92, as described in the eighth embodiment, the retardation plate 90 may be, for example, a quartz plate having a predetermined thickness.

[0111] Furthermore, in the projector of the ninth embodiment, if the polarization conversion function of the wavelength conversion element 13 of the light-emitting unit 10 is so high that the white light WL emitted from the wavelength conversion element 13 is converted into polarized light of a predetermined polarization direction due to the white light WL having a polarization direction perpendicular to the predetermined polarization direction even when the retardation plate 90 is not arranged, the retardation plate 90 may be omitted.

[0112] In the above description, the rod member 200 is a hollow member formed in a cylindrical shape. The cover member 200 is a solid material that fills the gap between the wavelength conversion element 13 and the retardation plate 90 in the Z direction. and a solid material filling the space between the retardation plate 90 and the incident-side polarizing element 80. Although not shown in the figure, the material of the rod member 200, which is a solid material, transmits white light WL and The material does not affect the polarization direction of the color light WL. If the refractive index of the rod member 200 satisfies the total reflection condition for the white light WL, Outside Be sure to apply it to the wall. The reflective film may not be provided.

[0113] Although the preferred embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. Furthermore, the configurations of multiple embodiments and modifications of the embodiments may be appropriately combined.

[0114] For example, in the projector of the seventh embodiment, the retardation plate 90 may be disposed on the optical path of the white light WL between the biconvex lens 33B of the pickup lens 30 and the polarizing plate 82 of the entrance-side polarizing element 80 shown in FIG. 8. The retardation plate 90 may also be disposed on the optical path of the white light WL between the phosphor layer 14 of the wavelength conversion element 13 and the plano-convex lens 33A of the pickup lens 30.

[0115] Furthermore, the entrance-side polarizing element 80 may be disposed on the optical path of the white light WL before and near the collimating lens 35. Furthermore, while Fig. 1 illustrates the projector 101 in which the optical system is configured substantially linearly along the Z direction, in the projectors of the above-described embodiments, appropriate reflecting members and deflecting members may be disposed on the optical paths of the white light WL and the image light IM, and the optical system may be configured in a shape other than linear. For example, in the projectors of the above-described embodiments, the optical system may be configured in an L-shape.

[0116] [Summary of this disclosure] The following is a summary of this disclosure. (Additional Note 1) A projector comprising: a light source that emits a first light; a wavelength conversion element that is irradiated with the first light and emits a second light having an emission wavelength different from that of the first light; an optical system that magnifies a luminous flux of the first light that has passed through the wavelength conversion element and a luminous flux of the second light emitted from the wavelength conversion element; a collimating lens that collimates the light magnified by the optical system; a light modulation element that receives the light collimated by the collimating lens and modulates the incident light to generate image light; an exit-side polarizing element into which the image light emitted from the light modulation element is incident; a projection lens that projects the image light emitted from the exit-side polarizing element; and an entrance-side polarizing element that transmits polarized light of a predetermined polarization direction and reflects polarized light other than the predetermined polarization direction, wherein non-linearly polarized light is incident on the entrance-side polarizing element, and the entrance-side polarizing element is disposed between the light source and the collimating lens on the optical path of the second light.

[0117] The configuration of Supplementary Note 1 converts non-linearly polarized light into linearly polarized light in an area closer to the light source than the collimating lens, and the amount of light irradiated to the collimating lens can be reduced compared to conventional projectors. As a result, deterioration of the collimating lens caused by the incidence of light can be reduced, and deterioration of the collimating lens can be prevented.

[0118] (Supplementary Note 2) The projector of Supplementary Note 1, wherein an incident-side polarizing element is disposed between the wavelength conversion element and the optical system.

[0119] The incident-side polarizing element can be made smaller by the configuration of Supplementary Note 2. In addition, since the incident-side polarizing element is disposed in a region closer to the light source than the optical system including the pickup lens, etc., a large portion of the light reflected by the incident-side polarizing element can be irradiated onto the wavelength conversion element.

[0120] (Supplementary Note 3) The projector of Supplementary Note 2, wherein the wavelength conversion element has a phosphor layer, and the surface of the phosphor layer opposite to the surface facing the light source and the incident side surface of the incident-side polarizing element are parallel to each other.

[0121] According to the configuration of Supplementary Note 3, the light reflected by the incident-side polarizing element is irradiated onto the wavelength conversion element, thereby improving the light utilization efficiency.

[0122] (Appendix 4) The projector according to appendix 2 or 3, wherein the incident-side polarizing element is in contact with the wavelength conversion element.

[0123] The configuration of Supplementary Note 4 allows a larger amount of light reflected by the incident-side polarizing element to be irradiated onto the wavelength conversion element, thereby further improving the light utilization efficiency.

[0124] (Appendix 5) The projector of Appendix 4, wherein the incident-side polarizing element is a wire grid polarizer, and the period of the wire grid polarizer is shorter than half the predetermined wavelength of the first light.

[0125] The configuration of Supplementary Note 5 makes it possible to dissipate heat from the wavelength conversion element via the wire grid polarizer.

[0126] (Supplementary Note 6) Any one of the projectors according to Supplementary Note 2 to 5, comprising a dichroic mirror disposed between the light source and the wavelength conversion element, the dichroic mirror transmitting the first light and reflecting at least a portion of the second light.

[0127] With the configuration of Appendix 6, light that is reflected by the incident side polarizing element and then enters the wavelength conversion element and passes through the wavelength conversion element is reflected toward the incident side polarizing element, thereby improving the light utilization efficiency of the projector.

[0128] (Appendix 7) The projector of Appendix 6, further comprising a light-transmitting member disposed between the light source and the dichroic mirror.

[0129] The configuration of Supplementary Note 7 allows the dichroic mirror to be stably held on the surface of the light-transmitting member by employing a manufacturing method such as vapor deposition of the dichroic mirror material on the surface of the light-transmitting member. In addition, if the light-transmitting member has excellent heat dissipation properties, the heat of the dichroic mirror can be dissipated well.

[0130] (Supplementary Note 8) The projector according to Supplementary Note 2, wherein the incident-side polarizing element is provided so as to cover a surface of the wavelength conversion element opposite to a surface facing the light source.

[0131] The configuration of Supplementary Note 8 allows a larger amount of light that is emitted from the wavelength conversion element and then reflected by the incident-side polarizing element to be irradiated onto the wavelength conversion element.

[0132] (Appendix 9) The projector of appendix 1, wherein the incident-side polarizing element is disposed between the optical system and the collimating lens.

[0133] The configuration of Supplementary Note 9 makes it possible to increase the installation space for the incident polarizing element in the projector. Secure and Enclose side This increases the degree of freedom in the location where the polarizing element is installed.

[0134] (Supplementary Note 10) The projector according to Supplementary Note 9, further comprising a dichroic mirror disposed between the light source and the wavelength conversion element, the dichroic mirror transmitting the first light and reflecting at least a portion of the second light.

[0135] The configuration of Supplementary Note 10 ensures a large installation space for the incident-side polarizing element in the projector, making it easy to install the incident-side polarizing element. In addition, the light that is reflected by the incident-side polarizing element, enters the wavelength conversion element 13, and then passes through the wavelength conversion element 13 is reflected by the dichroic mirror, improving the light utilization efficiency of the projector.

[0136] (Supplementary Note 11) Any one of Supplementary Notes 1 to 10, comprising a retardation plate disposed between the wavelength conversion element and the incident-side polarizing element.

[0137] The configuration of Supplementary Note 11 makes it possible to modulate the phase of light emitted from the wavelength conversion element after being reflected by the incident-side polarizing element, thereby suppressing a reduction in the transmittance of the first light and the second light at the incident-side polarizing element.

[0138] (Appendix 12) The projector of Appendix 11, wherein the retardation plate is in contact with the incident side polarizing element.

[0139] The configuration of Supplementary Note 12 makes it possible to stabilize the transmittance of the first light and the second light at the incident-side polarizing element.

[0140] (Appendix 13) The projector of appendix 11 or 12, wherein the retardation plate is a quarter-wave plate.

[0141] The configuration of Supplementary Note 13 makes it possible to increase the transmittance at the incident-side polarizing element of light having a polarization direction perpendicular to the predetermined polarization direction among the light reflected by the incident-side polarizing element, and as a result, it is possible to efficiently suppress a significant decrease in the transmittance of the first light and the second light at the incident-side polarizing element.

[0142] (Appendix 14) A projector according to Appendix 11, comprising a rod member that connects an edge of the light source and an edge of the incident-side polarizing element along the optical path, is arranged to surround at least the light source and the incident-side polarizing element, and reflects light that is irradiated onto the inner wall surface.

[0143] With the configuration of Appendix 14, the divergent light between the wavelength conversion element and the incident side polarizing element is reflected and focused by the rod member, thereby reducing the loss of light in the area between the wavelength conversion element and the incident side polarizing element. [Explanation of symbols]

[0144] 12...light source, 13...wavelength conversion element, 30...pickup lens, 35...parallelizing lens, 40...light modulation element, 50...exiting side polarizing element, 70...projection optical system (projection lens), 80...entering side polarizing element, 90...phase difference plate, 101...projector, 200...rod member, BL...blue light (first light), YL...yellow light (second light).

Claims

1. A light source that emits a first light; A wavelength at which the first light is irradiated and a second light having an emission wavelength different from that of the first light is emitted. A conversion element; The first light flux transmitted through the wavelength conversion element and the second light flux emitted from the wavelength conversion element an optical system for expanding the light flux of the second light; a collimating lens that collimates the light expanded by the optical system; The light collimated by the collimating lens is incident on the optical fiber, and the incident light is modulated to generate image light. a light modulation element forming the light beam; an exit side polarizing element onto which the image light emitted from the light modulation element is incident; a projection lens that projects the image light emitted from the emission-side polarizing element; An incident polarized light that transmits polarized light in a predetermined polarization direction and reflects polarized light in a direction other than the predetermined polarization direction. An element, Equipped with Nonlinearly polarized light is incident on the incident side polarizing element, On the optical path of the second light, the incident side polarizing element is disposed between the light source and the collimating lens. Located between The incident side polarizing element is disposed between the wavelength conversion element and the optical system. projector.

2. The wavelength conversion element has a phosphor layer, The surface of the phosphor layer opposite to the surface facing the light source and the incident side of the incident-side polarizing element The planes are parallel to each other. The projector according to claim 1 .

3. The incident side polarizing element is in contact with the wavelength conversion element. The projector according to claim 1 .

4. the incident-side polarizing element is a wire grid polarizer, a period of the wire grid polarizer is less than half of a predetermined wavelength of the first light; The projector according to claim 3 .

5. a first light transmitting element that is disposed between the light source and the wavelength conversion element and transmits the first light; a dichroic mirror that reflects the second light, The projector according to claim 1 .

6. a light-transmitting member disposed between the light source and the dichroic mirror; The projector according to claim 5 .

7. The incident side polarizing element is a surface of the wavelength conversion element opposite to a surface facing the light source. It is provided to cover The projector according to claim 1 .

8. A retardation plate is provided between the wavelength conversion element and the incident side polarizing element. The projector according to claim 1 .

9. The retardation plate is a quarter wave plate. The projector according to claim 8.

10. The retardation plate is in contact with the incident-side polarizing element. The projector according to claim 8.

11. The retardation plate is a quarter wave plate. The projector according to claim 10.

12. A periphery of the light source and a periphery of the incident-side polarizing element are connected along an optical path of the second light. , which is provided so as to surround at least the light source and the incident-side polarizing element and is irradiated onto the inner wall surface. A rod member that reflects light is provided. The projector according to claim 1 .

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