Projector

Abstract

The utility model provides a projector, which can reduce the number of parts and restrain large scale in a three-plate type projector. In the projector of the utility model, first light of a first wave band emitted from a first light source sequentially passes through a first light guide element and a first parallelization element and then enters a light synthesis element. Second light of a second wave band emitted from the second light source sequentially passes through the second light guide element and the second parallelization element and enters the light synthesis element. Third light of a third wave band emitted from the third light source sequentially passes through the third light guide element and the third parallelization element and enters the light synthesis element. A first focal length of the first parallelization element is longer than a first length from a first incident end to a first exit end of the first light guide element, and a second focal length of the second parallelization element is longer than a second length from a second incident end to a second exit end of the second light guide element. A third focal length of the third parallelization element is longer than a third length from a third incident end to a third exit end of the third light guide element.

Description

Technical Field

[0001] The utility model relates to a projector. Background Art

[0002] Conventionally, a projector having three liquid crystal panels, i.e., a three-panel projector, has been known as a light modulator for generating image light of each of the three primary colors. For example, Patent Document 1 discloses a projector comprising: a light source device having a light source unit and a separation and synthesis element; an illumination optical system; a color separation and synthesis optical system; and a projection optical system. The light source unit emits excitation light for a fluorescent body. The separation and synthesis element causes a portion of the light emitted from the light source unit to be incident on the fluorescent body, and another portion of the light emitted from the light source unit to be incident on a diffuser and reflected by the diffuser. The illumination optical system illuminates the light emitted from the light source device. The color separation and synthesis optical system performs color separation and synthesis on the light emitted from the illumination optical system. The projection optical system amplifies the color-synthesized image light and projects it onto an image display surface such as a screen.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-079820

[0004] In the three-panel projector disclosed in Patent Document 1, after white light is generated by a light source device, a color separation and synthesis optical system, located downstream of the light source device, separates the white light into its respective colors. Therefore, the projector disclosed in Patent Document 1 requires a color separation and synthesis optical system in addition to the light source device. This increases the number of components and potentially increases the size of the projector. Therefore, in three-panel projectors, measures are needed to reduce the number of components and prevent their size from increasing. Utility Model Content

[0005] A projector according to one embodiment of the present invention comprises: a first light source emitting first light of a first wavelength band; a second light source emitting second light of a second wavelength band different from the first wavelength band; a third light source emitting third light of a third wavelength band different from the first wavelength band and the second wavelength band; a first light guide element having a first incident end for the first light emitted from the first light source to enter and a first exit end for emitting the first light, so as to make the in-plane illumination of the first light uniform; a second light guide element having a second incident end for the second light emitted from the second light source to enter and a second exit end for emitting the second light, so as to make the in-plane illumination of the second light uniform; a third light guide element having a third incident end for the third light emitted from the third light source to enter and a third exit end for emitting the third light, so as to make the in-plane illumination of the third light uniform; a first parallelizing element A device for parallelizing the first light emitted from the first light guide element; a second parallelizing element for parallelizing the second light emitted from the second light guide element; a third parallelizing element for parallelizing the third light emitted from the third light guide element; a first light modulating element for modulating the first light emitted from the first parallelizing element based on image information; a second light modulating element for modulating the second light emitted from the second parallelizing element based on image information; a third light modulating element for modulating the third light emitted from the third parallelizing element based on image information; a light synthesizing element for synthesizing the first light emitted from the first light modulating element, the second light emitted from the second light modulating element, and the third light emitted from the third light modulating element and emitting the synthesized light; and a projection optical system for projecting the light emitted from the light synthesizing element. The first focal length of the first parallelizing element is longer than a first length from the first incident end to the first emitting end, the second focal length of the second parallelizing element is longer than a second length from the second incident end to the second emitting end, and the third focal length of the third parallelizing element is longer than a third length from the third incident end to the third emitting end. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a schematic diagram showing the structure of a projector according to one embodiment.

[0007] Figure 2 yes Figure 1 Schematic diagram of the green light emitting part of the projector.

[0008] Figure 3 yes Figure 1 Schematic diagram of the green light emitting unit and incident-side polarizing element of a projector.

[0009] Figure 4 yes Figure 1 Schematic diagram of the green light emitting unit, incident-side polarization element, and light modulation element of the projector.

[0010] Figure 5 yes Figure 1A schematic diagram of a modified example of the green light emitting portion of a projector.

[0011] Figure 6 yes Figure 1 A schematic diagram of a modified example of the green light emitting portion of a projector.

[0012] Figure 7 yes Figure 1 A schematic diagram of a modified example of the green light emitting portion of a projector.

[0013] Figure 8 yes Figure 1 A schematic diagram of a modified example of the green light emitting portion of a projector.

[0014] Figure 9 yes Figure 1 Schematic diagram of the main parts of the green light emitting section of the projector.

[0015] Description of labels

[0016] 121: Light source (first light source); 122: Light source (second light source); 123: Light source (third light source); 141: Light guiding element (first light guiding element); 142: Light guiding element (second light guiding element); 143: Light guiding element (third light guiding element); 161: Parallelizing element (first parallelizing element); 162: Parallelizing element (second parallelizing element); 163: Parallelizing element (third parallelizing element); 181: Light modulating element (first light modulating element); 182: Light modulating element (second light modulating element); 183: Light modulating element (third light modulating element); 200: Light synthesizing element; 301: Projector. DETAILED DESCRIPTION

[0017] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each of the drawings, the scale of each component may be changed depending on the component to facilitate viewing.

[0018] First, refer to Figures 1 to 5 An embodiment of the present invention will be described. Figure 1 : is a schematic diagram showing the structure of a projector 301 according to one embodiment of the present invention. The projector 301 is an image display device having three liquid crystal panels as light modulation devices, and is a so-called three-panel projector. Figure 1 As shown, the projector 301 has a blue light emitting section 101, a green light emitting section 102, a red light emitting section 103, incident-side polarization elements 171, 172, 173, light modulation elements 181, 182, 183, emitting-side polarization elements 175, 176, 177, a photosynthetic element 200, and a projection optical system 250.

[0019] The blue light emitting section 101 emits blue light LB. In the following description, an axis parallel to the optical axis of the blue light LB emitted from the blue light emitting section 101 is set as the D1 direction. One side in the D1 direction is set as the -D1 side, and the side opposite to the -D1 side in the D1 direction is set as the +D1 side. A direction perpendicular to the D1 direction within a plane containing the optical axis of the blue light LB is set as the D2 direction. One side in the D2 direction is set as the -D2 side, and the side opposite to the -D2 side in the D2 direction is set as the +D2 side. A direction perpendicular to the D1 direction and the D2 direction is set as the D3 direction. The blue light LB emitted from the blue light emitting section 101 travels along the D1 direction toward the +D1 side.

[0020] The blue light emitting section 101 includes a light source 121, a light guide element 141, and a parallelizing element 161. The light source 121 is supported by a substrate 111. The light source 121 is disposed on the +D1 side of the surface of the substrate 111 that is parallel to the plane including the D2 and D3 directions. The light emitting surface of the light source 121 is arranged approximately parallel to the plane including the D2 and D3 directions and is the surface of the light source 121 that is opposite in the D1 direction from the surface that contacts the +D1 side of the substrate 111. The light source 121 serves as a first light source and emits blue light LB in the blue wavelength band within the visible wavelength range. The blue wavelength band serves as the first wavelength band. The blue light LB serves as the first light. The blue light LB emanates from the light emitting surface of the light source 121 at a predetermined radiation angle, centered on an axis that passes through the center of the light emitting surface of the light source 121 and is parallel to the D1 direction, and is emitted toward the +D1 side. The blue wavelength band is, for example, the 420 nm to 500 nm wavelength band.

[0021] The light source 121 is composed of, for example, a light emitting diode (LED) that emits blue light LB. Furthermore, the light source 121 may be composed of a single LED or a plurality of LEDs. When the light source 121 is composed of a plurality of LEDs, the plurality of LEDs are arranged in an area occupied by the light source 121 within a plane including the directions D2 and D3.

[0022] The substrate 111 is made of metal, for example, and also functions as a heat dissipating member that receives heat from the light source 121 emitting the blue light LB and releases the heat to an external space.

[0023] Light guide element 141 is disposed on the optical path of blue light LB emitted from light source 121, positioned closer to the +D1 side of light source 121 and overlapping with light source 121 in the D2 and D3 directions. Light guide element 141 corresponds to a first light guide element and has an incident end 141a on the -D1 side of the D1 direction, an emitting end 141b on the +D1 side, and a side surface 141s and a reflecting surface 141r extending between incident end 141a and emitting end 141b in the D1 direction. Incident end 141a corresponds to a first incident end and extends parallel to a plane including the D2 and D3 directions. The shape of incident end 141a when viewed from the D1 direction is the same as the shape of the light-emitting surface of light source 121 when viewed from the same direction, for example, a rectangle. The size of the incident end 141a within the plane containing the D2 and D3 directions can be equal to the size of the light-emitting surface of the light source 121 within the plane containing the D2 and D3 directions, but is preferably moderately larger than the size of the light-emitting surface of the light source 121 within the plane containing the D2 and D3 directions. The emitting end 141b corresponds to the first emitting end, extending parallel to the plane containing the D2 and D3 directions and being larger than the incident end 141a. The shape of the emitting end 141b when viewed from the D1 direction is the same as the modulation surface of the light modulator 181 when viewed from the same direction, for example, a rectangle. The size of the emitting end 141b within the plane containing the D2 and D3 directions is equal to the size of the modulation surface of the light modulator 181 within the plane containing the D2 and D3 directions. The side surface 141s and the reflective surface 141r connect the periphery of the incident end 141a and the periphery of the emitting end 141b in the D1 direction.

[0024] The blue light LB emitted from the light source 121 enters the light guide element 141 from the incident end 141a. In the light guide element 141, the area surrounded by the incident end 141a, the emission end 141b, and the reflection surface 141r is the area through which the blue light LB is transmitted. The size of the area surrounded by the incident end 141a, the emission end 141b, and the reflection surface 141r within the plane including the D2 and D3 directions increases as the area moves from the -D1 side toward the +D1 side of the D1 direction. In addition, as the area moves from the -D1 side toward the +D1 side, the shape of the area surrounded by the incident end 141a, the emission end 141b, and the reflection surface 141r within the plane including the D2 and D3 directions changes from the shape of the light emitting surface of the light source 121 when viewed from the D1 direction to the shape of the modulation surface of the light modulator 181.

[0025] Side surface 141s of light guide element 141 and a reflective surface 141r (described later) provided on side surface 141s form a predetermined angle with respect to an imaginary line perpendicular to incident end 141a and the optical axis. As light moves from the -D1 side toward the +D1 side, the light moves away from the imaginary line within a plane encompassing directions D2 and D3. Blue light LB incident on light guide element 141 propagates from the -D1 side toward the +D1 side within the region bounded by incident end 141a, exit end 141b, and reflective surface 141r.

[0026] When the shape of the modulation surface of the light modulator 181 when viewed along the D1 direction is a rectangle, the shape of the light emitting surface of the light source 121 when viewed along the D1 direction also conforms to a rectangle. In this case, the prescribed angle α, i.e., the cone angle, formed by the side surface 141s and the reflective surface 141r including the short side of the rectangle relative to the aforementioned imaginary line and the optical axis is preferably in the range of 7° to 22°. The prescribed angle β, i.e., the cone angle, formed by the side surface 141s and the reflective surface 141r including the long side of the rectangle relative to the aforementioned imaginary line and the optical axis is preferably in the range of 14° to 36°. The preferred ranges of the angles α and β are confirmed by numerical simulation based on the structure of the blue light emitting portion 101 and ray tracing.

[0027] A portion of the blue light LB incident on the light guide element 141 forms an angle smaller than a predetermined angle with respect to the aforementioned imaginary axis and the optical axis, and thus propagates directly from the incident end 141a to the emitting end 141b without incident on the reflecting surface 141r. The remaining portion of the blue light LB incident on the light guide element 141 forms an angle greater than a predetermined angle with respect to the aforementioned imaginary axis and the optical axis, and is incident on the reflecting surface 141r from the incident end 141a at least once. After being reflected by the reflecting surface 141r, it reaches the emitting end 141b. The path of the blue light LB within the area surrounded by the incident end 141a, the emitting end 141b, and the reflecting surface 141r varies depending on the angle of incidence on the incident end 141a, resulting in multiple paths with different numbers of reflections at the reflecting surface 141r. As a result, the illuminance distribution of blue light LB propagating within the area surrounded by incident end 141a, emitting end 141b, and reflective surface 141r is uniformed within a plane encompassing directions D2 and D3. In other words, light guide element 141 uniformizes the illuminance distribution of incident blue light LB within a plane encompassing directions D2 and D3. The blue light LB, with its uniform illuminance distribution, is emitted from emitting end 141b toward the +D1 side.

[0028] The light guide element 141 is a reflector made of a transparent material such as optical glass. The reflector has a hollow housing. When viewed along the D1 direction, the end of the reflector's housing on the -D1 side has the same shape and size as the incident end 141a and the light-emitting surface of the light source 121, for example, forming a rectangular frame. The end of the reflector's housing on the +D1 side has the same shape and size as the emitting end 141b and the modulation surface of the light modulator 181, for example, forming a rectangular frame of a different size from the end on the -D1 side.

[0029] The reflector is formed, for example, by a plate-like component made of a transparent material. As described above, if the shape of the incident end 141a and the emission end 141b when viewed from the D1 direction is a rectangle, the reflector is formed by four trapezoidal plate-like components. The lengths of the sides of the four plate-like components on the -D1 side corresponding to the upper base, which are parallel to the D2 direction or the D3 direction, are set according to the size of the incident end 141a and the light-emitting surface of the light source 121 in the D2 direction or the D3 direction. The lengths of the sides of the four plate-like components on the +D1 side corresponding to the lower base, which are parallel to the D2 direction or the D3 direction, are set according to the size of the emission end 141b and the modulation surface of the light modulator 181 in the D2 direction or the D3 direction. Of the four plate-like components, the side corresponding to one leg of one of the two plate-like components is connected to the side corresponding to the other leg of the other plate-like component.

[0030] As described above, when the reflector is formed from a plate-like member made of a transparent component, side surface 141s, i.e., the surface of the plate-like member facing the exterior of the reflector, functions as reflective surface 141r. In the reflector of light guide element 141, to increase the reflectivity of blue light LB incident on light guide element 141 from incident end 141a near side surface 141s, a reflective film 251, such as a dielectric multilayer film, is provided on the surface of the plate-like member constituting the reflector that faces the interior. A portion of the blue light LB incident on the interior of the reflector of light guide element 141 from incident end 141a is reflected by reflective film 251 and travels toward the +D1 side.

[0031] The intensity of the blue light LB reflected by the reflective film 251 and emitted from the reflective film 251 sometimes depends on the angle of incidence of the blue light LB incident on the reflective film 251. When the reflective film 251 is composed of a dielectric multilayer film, the angle of incidence dependence of the intensity of the blue light LB emitted from the reflective film 251 varies depending on parameters such as the refractive index, thickness, and number of films included in the dielectric multilayer film. As described above, for example, when the angle α is in the range of 7° to 22° and the angle β is in the range of 14° to 36°, the reflective film 251 is designed so that the intensity of the blue light LB emitted from the reflective surface 141r is highest at an angle of incidence of 60° to 90°, and the parameters of the dielectric multilayer film are appropriately determined. The relationship between the angle of incidence of the blue light LB on the reflective surface 141r and the reflective film 251 and the intensity of the blue light LB emitted from the reflective surface 141r and the reflective film 251 was obtained through numerical simulations based on the structure of the blue light emitting unit 101 and ray tracing.

[0032] In addition, when the reflector is composed of a plate-like component composed of a transparent component, and the plate surface of the plate-like component facing the external space of the reflector acts as a reflecting surface 141r, a portion of the blue light LB that is incident from the incident end 141a to the internal space of the reflector of the light-guiding element 141 is incident on the plate-like component from the plate surface facing the internal space of the reflector and refracted, is reflected by the plate surface facing the external space of the reflector, propagates again in the plate-like component, is refracted by the plate surface facing the internal space of the reflector, is emitted into the internal space of the reflector, and moves toward the +D1 side.

[0033] Parallelizer 161 is disposed on the optical path of blue light LB emitted from light guide element 141, positioned closer to the +D1 side of light guide element 141 and overlapping with light guide element 141 in directions D2 and D3. Parallelizer 161 serves as a first parallizer and parallelizes blue light LB emitted from light guide element 141 along direction D1.

[0034] The parallelizing element 161 is, for example, a plano-convex lens having an incident surface consisting of a flat surface perpendicular to the D1 direction and an exit surface consisting of a convex surface protruding toward the exit side of the blue light LB. The focal point of the plano-convex lens constituting the parallelizing element 161 is located at least on the -D1 side of the parallelizing element 161 and on the side opposite to the +D1 side from which the blue light LB is emitted from the parallelizing element 161, and further on the -D1 side of the light guide element 141. The incident surface of the plano-convex lens of the parallelizing element 161 is in contact with the exit end 141b of the light guide element 141. By bringing the parallelizing element 161 into contact with the exit end 141b, the blue light LB emitted from the exit end 141b of the light guide element 141 is taken into the parallelizing element 161 to the maximum extent possible, thereby suppressing the loss of the blue light LB. However, the parallelizing element 161 may be an optical lens other than a plano-convex lens capable of parallelizing the incident blue light LB, and may be disposed at an appropriate distance from the light guide element 141 in the D1 direction.

[0035] The focal length f1 of the parallelization element 161 is equivalent to the first focal length, which is longer than the length g1 from the incident end 141a to the emission end 141b of the light-guiding element 141 in the direction of D1. The length g1 is equivalent to the first length. Specifically, the focal length f1 of the parallelization element 161 is preferably greater than 1.1 times the length g1 of the light-guiding element 141. The focal length f1 is more preferably greater than 1.1 times the length g1 and less than 2.0 times the length g1. By setting the focal length f1 within the above range, the blue light LB emitted from the light source 121 is efficiently parallelized, and the utilization efficiency of the blue light LB is improved. The preferred range of the focal length f1 is confirmed by numerical simulation based on the structure of the blue light emitting portion 101 and ray tracing.

[0036] If the focal length f1 of the parallelizer 161 is shorter than 1.1 times the length g1 of the light guide element 141, the illumination range of the blue light LB emitted from the parallelizer 161 is excessively reduced. This may result in a portion of the original image not being displayed when the image light converted by the subsequent light modulator 181 is projected and magnified and displayed on the screen SC. On the other hand, if the focal length f1 is longer than 2.0 times the length g1, a portion of the blue light LB emitted from the parallelizer 161 will not be incident on the light modulator 181, which is positioned further downstream than the parallelizer 161. Consequently, the utilization efficiency of the blue light LB may be reduced.

[0037] The incident-side polarizing element 171 is disposed on the optical path of the blue light LB emitted from the parallelizing element 161, positioned closer to the +D1 side than the parallelizing element 161 and overlapping with the parallelizing element 161 in the D2 and D3 directions. The incident-side polarizing element 171 contacts the light modulating element 181, for example, from the -D1 side, but may also be disposed with an appropriate spacing from the light modulating element 181 in the D1 direction. The incident-side polarizing element 171 acts as a first polarizing element, directing a predetermined polarization within the blue light LB emitted from the parallelizing element 161 toward the +D1 side along the D1 direction. The predetermined polarization corresponds to the first polarization component, for example, S-polarization. The incident-side polarizing element 171 is, for example, a reflective polarizing plate having a plate surface parallel to a plane including the D2 and D3 directions. The incident-side polarizing element 171 transmits a portion of the incident blue light LB containing the predetermined polarization toward the +D1 side and reflects another portion of the blue light LB toward the -D1 side.

[0038] Light modulator 181 is disposed on the optical path of blue light LB emitted from incident-side polarizer 171, positioned closer to the +D1 side of incident-side polarizer 171 and overlapping with incident-side polarizer 171 in the D2 and D3 directions. Light modulator 181 serves as a first light modulator and modulates blue light LB emitted from incident-side polarizer 171 based on image information transmitted from an external image forming device (not shown), such as a computer, connected to light modulator 181.

[0039] The light modulator 181 is, for example, a transmissive liquid crystal panel. The liquid crystal panel constituting the light modulator 181 has a plurality of pixels, not shown. Each pixel is provided with a switching element. The switching element is, for example, a polysilicon thin film transistor (TFT). An electrical signal corresponding to the brightness of the blue light at the relative position of each pixel in the modulation surface of the light modulator 181 in the image projected by the projector 301 is supplied to the switching element of each pixel. Each pixel modulates the vibration direction of the blue light LB incident from the incident-side polarizing element 171 by the action of the switching element corresponding to the above-mentioned electrical signal, thereby generating blue image light IB. The image light IB is equivalent to the first light. The light modulator 181 emits the image light IB generated by the liquid crystal panel toward the +D1 side along the D1 direction.

[0040] The output-side polarizing element 175 is disposed on the optical path of the image light IB emitted from the light modulator 181, positioned closer to the +D1 side of the light modulator 181 and overlapping the light modulator 181 in the D2 and D3 directions. For example, the output-side polarizing element 175 contacts the light modulator 181 from the +D1 side, but may also be disposed with an appropriate spacing from the light modulator 181 in the D1 direction. The output-side polarizing element 175 acts as a fourth polarizing element, emitting a predetermined polarization within the image light IB emitted from the light modulator 181 toward the +D1 side along the D1 direction. This predetermined polarization corresponds to the fourth polarization component, for example, P-polarization. The output-side polarizing element 175 is, for example, a reflective or absorptive polarizer having a plate surface parallel to a plane including the D2 and D3 directions. To suppress return light and stray light directed toward the light modulator 181, an absorptive polarizer is preferably used as the output-side polarizing element 175. The output-side polarization element 175 transmits a portion of the incident image light IB including predetermined polarized light toward the +D1 side, and reflects the other portion of the image light IB toward the −D1 side.

[0041] The green light emitting section 102 is positioned closer to the +D1 side and the -D2 side than the blue light emitting section 101, and is positioned in a region overlapping the blue light emitting section 101 in the D3 direction. The green light emitting section 102 emits green light LG. The green light LG emitted from the green light emitting section 102 travels toward the +D2 side along the D2 direction.

[0042] The green light emitting unit 102 includes a light source 122 , a light guide element 142 , and a parallelizing element 162 . Figure 2 1 is a schematic diagram of the green light emitting section 102 , and is a diagram when the green light emitting section 102 is viewed along the direction D3 . Figure 3 1 is a schematic diagram of the green light emitting section 102 and the incident side polarizing element 172, and is a diagram when the green light emitting section 102 and the incident side polarizing element 172 are viewed along the D3 direction. Figures 1 to 3 As shown, light source 122 is supported by substrate 112. Light source 122 is disposed on substrate 112 on the +D2 side of a surface parallel to a plane including directions D1 and D3. Light emitting surface 122a of light source 122 is arranged substantially parallel to the plane including directions D1 and D3. It is the surface of light source 122 opposite to the surface in contact with the +D2 side of substrate 112 in the D2 direction. Light source 122 serves as a second light source and emits green light LG in the green wavelength range within the visible wavelength range. The green wavelength range is, for example, between 500 nm and 600 nm.

[0043] Light source 122 is comprised of, for example, an LED that emits green light LG. In order to optimize the green wavelength band and intensity of green light LG relative to the blue wavelength band and intensity of blue light LB emitted by blue light emitting section 101 and the red wavelength band and intensity of red light LR emitted by red light emitting section 103 in green light emitting section 102, light source 122 is comprised of an LED with a built-in phosphor, and includes an LED main body 125 made of a semiconductor and a phosphor 124. LED main body 125 is disposed on the +D2 side surface of substrate 112. For example, LED main body 125 may be an LED that emits blue light LB, similar to light source 121. Phosphor 124 is laminated on emission surface 125a on the +D2 side of LED main body 125. Phosphor 124 is excited by the light emitted from LED main body 125 as excitation light, and emits green light LG as fluorescent light from emission surface 124a. The type and material of the LED body 125 and the type and material of the phosphor 124 are appropriately selected so that the phosphor 124 excited by the light emitted from the LED body 125 emits green light LG in the green wavelength band.

[0044] The light source 122 may be composed of a single LED or a plurality of LEDs as in the case of the light source 121. When the light source 122 is composed of a plurality of LEDs, the plurality of LEDs are arranged in the area occupied by the light source 122 in the plane including the directions D1 and D3.

[0045] The substrate 112 is made of metal, for example, and also functions as a heat dissipating member that receives heat from the light source 122 emitting the green light LG and releases the heat to an external space.

[0046] Light guide element 142 is disposed on the optical path of green light LG emitted from light source 122, positioned closer to the +D2 side of light source 122 and overlapping with light source 122 in the D1 and D3 directions. Light guide element 142 serves as a second light guide element and includes an incident end 142a on the -D2 side in the D2 direction, an emitting end 142b on the +D2 side, and a side surface 142s and a reflecting surface 142r extending between incident end 142a and emitting end 142b in the D2 direction. Incident end 142a serves as a second incident end and extends parallel to a plane encompassing the D1 and D3 directions. The shape of incident end 142a when viewed from the D2 direction is the same as the shape of the light-emitting surface 122a of light source 122 when viewed from the same direction, for example, a rectangle. The size of the incident end 142a within the plane including the D1 and D3 directions can be equal to the size of the light-emitting surface 122a of the light source 122 within the plane including the D1 and D3 directions, but is preferably moderately larger than the size of the light-emitting surface 122a within the plane including the D1 and D3 directions. The emitting end 142b serves as a second emitting end, extending parallel to the plane including the D1 and D3 directions and being larger than the incident end 142a. The shape of the emitting end 142b when viewed from the D2 direction is the same as the modulation surface of the light modulator 182 when viewed from the same direction, for example, a rectangle. The size of the emitting end 142b within the plane including the D1 and D3 directions is equal to the size of the modulation surface of the light modulator 182 within the plane including the D1 and D3 directions. The side surface 142s and the reflective surface 142r connect the periphery of the incident end 142a and the periphery of the emitting end 142b in the D2 direction.

[0047] Green light LG emitted from light source 122 enters light guide element 142 from incident end 142a. Within light guide element 142, the area enclosed by incident end 142a, emitting end 142b, and reflecting surface 142r is the region through which green light LG is transmitted. The size of the area enclosed by incident end 142a, emitting end 142b, and reflecting surface 142r increases within a plane encompassing directions D1 and D3 as it progresses from the -D2 side toward the +D2 side of the D2 direction. Furthermore, as it progresses from the -D2 side toward the +D2 side, the shape of the area enclosed by incident end 142a, emitting end 142b, and reflecting surface 142r within a plane encompassing directions D1 and D3 changes from the shape of light emitting surface 122a of light source 122 as viewed from the D2 direction to the shape of the modulation surface of light modulator 182.

[0048] Side surface 142s of light guide element 142 and, as will be described later, reflective surface 142r provided on side surface 142s form a predetermined angle with respect to an imaginary line VX perpendicular to incident end 142a and the optical axis. As light moves from the -D2 side toward the +D2 side, it moves away from the imaginary line within a plane encompassing the D2 and D3 directions. Green light LG incident on light guide element 142 propagates from the -D2 side toward the +D2 side within the region enclosed by incident end 142a, exit end 142b, and reflective surface 142r.

[0049] If the modulation surface of the light modulator 182 is rectangular when viewed along direction D2, the light-emitting surface 122a of the light source 122 also conforms to a rectangle when viewed along direction D2. In this case, the angle α formed by the side surface 142s and the reflective surface 142r, which include the short sides of the rectangle, with respect to the aforementioned imaginary line and the optical axis is preferably within a range of 7° to 22°. The angle β formed by the side surface 142s and the reflective surface 142r, which include the long sides of the rectangle, with respect to the aforementioned imaginary line and the optical axis is preferably within a range of 14° to 36°.

[0050] A portion of the green light LG incident on the light guide element 142 forms an angle less than angle α or angle β with respect to the imaginary axis VX and the optical axis, and thus propagates directly from the incident end 142a to the emission end 142b without incident on the reflection surface 142r. The remaining portion of the green light LG incident on the light guide element 142 forms an angle greater than angle α or angle β with respect to the imaginary axis VX and the optical axis, and thus propagates once from the incident end 142a to the reflection surface 142r, after being reflected by the reflection surface 142r, and then reaches the emission end 142b. The remaining portion of the green light LG incident on the light guide element 142, excluding the portion of the green light LG, enters the reflection surface 142r from the incident end 142a two or more times, and after being repeatedly reflected by the reflection surface 142r, reaches the emission end 142b. The path of green light LG within the area bounded by incident end 142a, exit end 142b, and reflective surface 142r varies depending on the angle of incidence at incident end 142a, resulting in multiple paths with varying numbers of reflections at reflective surface 142r. Consequently, the illuminance distribution of green light LG propagating within the area bounded by incident end 142a, exit end 142b, and reflective surface 142r is uniform within the plane encompassing directions D1 and D3. In other words, light guide element 142 uniformizes the illuminance distribution of the incident green light LG within the plane encompassing directions D1 and D3. The green light LG, with its uniform illuminance distribution, is emitted from exit end 142b toward the +D2 side.

[0051] Like light guide element 141, light guide element 142 is a hollow reflector formed from a plate-like member made of a transparent material such as optical glass. When viewed along direction D2, the reflector's frame's -D2-side end has the same shape and size as incident end 142a and light-emitting surface 122a of light source 122, and is, for example, formed into a rectangular frame. The reflector's frame's +D2-side end has the same shape and size as emitting end 142b and the modulation surface of light modulator 182, and is, for example, formed into a rectangular frame of a different size from the -D2-side end.

[0052] The reflector of the light guide element 142 is constructed by connecting the legs of four trapezoidal plate-like members. The lengths of the sides of the four plate-like members, corresponding to the -D2 side of the upper base and parallel to the D1 or D3 direction, are set based on the size of the incident end 142a and the light-emitting surface 122a in the D1 or D3 direction. The lengths of the sides of the four plate-like members, corresponding to the +D2 side of the lower base and parallel to the D1 or D3 direction, are set based on the size of the emitting end 142b and the modulation surface of the light modulator 182 in the D1 or D3 direction.

[0053] In the reflector of the light guide element 142, a reflective film 252, such as a dielectric multilayer film, is also provided on the plate surface of the plate-like member constituting the reflector opposite to the side surface 142s, i.e., the plate surface of the plate-like member facing the interior space, in order to increase the reflectivity of the green light LG incident on the light guide element 142 from the incident end 142a near the side surface 142s. A portion of the green light LG, including the light beam Lg2, incident on the interior space of the reflector of the light guide element 142 from the incident end 142a is reflected by the reflective film 252 and travels toward the +D2 side.

[0054] The intensity of the green light LG reflected by the reflective film 252 and emitted from the reflective film 252 sometimes depends on the angle of incidence of the green light LG entering the reflective film 252. When the reflective film 252 is composed of a dielectric multilayer film, the angle of incidence dependence of the intensity of the green light LG emitted from the reflective film 252 varies depending on parameters such as the refractive index, thickness, and number of films included in the dielectric multilayer film. As described above, for example, when the angle α is in the range of 7° to 22° and the angle β is in the range of 14° to 36°, the reflective film 252 is designed so that the angle of incidence of the green light LG emitted from the reflective surface 142r and the reflective film 252, at which the intensity of the green light LG is highest, is within a range of 60° to 90°. The parameters of the dielectric multilayer film are appropriately determined. The relationship between the angle of incidence of the green light LG on the reflective film 252 and the intensity of the green light LG emitted from the reflective film 252 is also determined through numerical simulations based on the structure of the green light emitting portion 102 and ray tracing.

[0055] Parallelizer 162 is disposed on the optical path of green light LG emitted from light guide element 142, positioned closer to the +D2 side of light guide element 142 and overlapping with light guide element 142 in directions D1 and D3. Parallelizer 162 serves as a second parallizer and parallelizes green light LG emitted from light guide element 142 along direction D2.

[0056] The parallelizing element 162 is, for example, a plano-convex lens having an incident surface 162a formed of a flat surface perpendicular to the direction D2, and an exit surface 162b formed of a convex surface protruding toward the exit side of the green light LG. The focal point F2 of the plano-convex lens constituting the parallelizing element 162 is located at least on the -D2 side of the parallelizing element 162 and on the side opposite to the +D2 side from which the green light LG is emitted from the parallelizing element 162, and further on the -D2 side of the light guide element 142. The incident surface 162a of the parallelizing element 162 contacts the exit end 142b of the light guide element 142. The contact between the parallelizing element 162 and the exit end 142b allows the green light LG emitted from the exit end 142b of the light guide element 142 to be taken into the parallelizing element 162 to the greatest extent possible, thereby suppressing the loss of the green light LG. However, the collimating element 162 may be an optical lens other than a plano-convex lens capable of collimating the incident green light LG, and may be arranged at an appropriate distance from the light guide element 142 in the D2 direction.

[0057] The focal length f2 of the parallelizing element 162 corresponds to the second focal length and is longer than the length g2 from the incident end 142a to the emitting end 142b of the light guide element 142 in the direction D2. The length g2 corresponds to the second length.

[0058] like Figure 2As shown in detail, light ray Lg1, a portion of the green light LG incident on light guide element 142, does not strike reflective surface 142r once, but instead propagates directly from incident end 142a to exit end 142b. Light ray Lg2, the remaining portion of the green light LG incident on light guide element 142, strikes reflective surface 142r once from incident end 142a, is reflected by reflective surface 142r, and then reaches exit end 142b. Ignoring the action of parallelization element 162, the combined vector VG of light rays Lg1 and Lg2 emitted from exit end 142b toward the +D2 side is represented by a dotted line. When combined vector VG at exit end 142b is extended from its base end on the -D2 side toward the -D2 side in parallel with combined vector VG, a focal point F2 is formed at a position where the centerline of the planes containing the D1 and D3 directions of parallelization element 162 and light guide element 142 intersects the optical axis. As described above, the paths of the green light LG propagating within the light guide element 142 are numerous, in addition to the paths of the light rays Lg1 and Lg2. Assuming the effect of the parallelizer 162 is ignored, when the composite vector of the multiple light rays contained in the green light LG emitted from the emission end 142b toward the +D2 side is extended toward the -D2 side, the intersection of the centerline of the parallelizer 162 and light guide element 142, and the optical axis, does not strictly converge at a single point. Instead, the focal point F2 caused by the composite vector VG is dispersed within a narrow region in the D2 direction. As a result, the focal point F2 of the plano-convex lens of the parallelizer 162 slightly expands in the D2 direction, but macroscopically, it forms a single point.

[0059] Furthermore, similar to the green light emitting section 102, in the blue light emitting section 101, assuming that the effect of the parallelizer 161 is ignored, when the composite vector of the multiple light rays contained in the blue light LB emitted from the emission end 141b toward the +D1 side is extended toward the -D1 side, the intersection of the center line of the parallelizer 161 and the light guide element 141 and the optical axis does not strictly converge at a single point, but is instead spread over a narrow area in the D1 direction. As a result, the focal point F1 of the plano-convex lens of the parallelizer 161 slightly expands in the D1 direction, but macroscopically, it is a single point.

[0060] Since the focal length f2 of the parallelizing element 162 is set to the -D2 side of the light guide element 142 and longer than the length g2 of the light guide element 142 according to the position of the focus F2 based on the above principle, the multiple light rays included in the green light LG are effectively parallelized with respect to the D2 direction as shown by the thick lines. Figure 2, the relationship between the focal length f2 of the parallelization element 162 and the length g2 of the light-guiding element 142, and the effects caused by the focal length f2 and the length g2 are explained, but the contents described are also applicable to the relationship between the focal length f1 of the parallelization element 161 of the above-mentioned blue light emitting portion 101 and the length g1 of the light-guiding element 141, and the effects caused by the focal length f1 and the length g1.

[0061] Specifically, the focal length f2 of the parallelization element 162 is preferably at least 1.1 times the length g2 of the light guide element 142. More preferably, the focal length f2 is at least 1.1 times the length g2 and no more than 2.0 times the length g2. By setting the focal length f2 within the above range, the green light LG emitted from the light source 122 is efficiently parallelized, thereby improving the utilization efficiency of the green light LG. The preferred range of the focal length f2 was also confirmed through numerical simulations based on the structure of the green light emitting unit 102 and ray tracing.

[0062] If the focal length f2 of the parallelizer 162 is shorter than 1.1 times the length g2 of the light guide element 142, the illumination range of the green light LG emitted from the parallelizer 162 is excessively reduced. This may result in a portion of the original image not being displayed when the subsequent light modulator 182 converts the green light into image light and projects it into image light, which is then magnified and displayed on the screen SC. On the other hand, if the focal length f2 is longer than 2.0 times the length g2, a portion of the green light LG emitted from the parallelizer 162 will not be incident on the light modulator 182, which is positioned further downstream than the parallelizer 162. Consequently, the utilization efficiency of the green light LG may be reduced.

[0063] like Figures 1 to 3 As shown, the incident-side polarizing element 172 is provided on the optical path of the green light LG emitted from the collimating element 162, and is arranged on the +D2 side of the collimating element 162 and overlaps with the collimating element 162 in the D1 and D3 directions. The incident-side polarizing element 172 contacts the light modulating element 182 from the -D2 side, for example, but may also be arranged with an appropriate distance therefrom in the D2 direction.

[0064] The incident-side polarizing element 172 acts as a second polarizing element, directing a predetermined polarization of the green light LG emitted from the parallelizing element 162 toward the +D2 side along the D2 direction. The predetermined polarization corresponds to the second polarization component and is, for example, S-polarized light. The incident-side polarizing element 172 is, for example, a reflective polarizer having a plate surface parallel to a plane including the D1 and D3 directions. The incident-side polarizing element 172 transmits a portion of the incident green light LG containing the predetermined polarization toward the +D2 side, while reflecting the remaining portion toward the -D2 side.

[0065] like Figure 3As shown in detail, the green light LG emitted from light source 122 is randomly polarized light containing at least P-polarized light and S-polarized light. The S-polarized component of the green light LG emitted from light source 122, i.e., green light LGS, and the P-polarized component of the green light LG, i.e., green light LGP, pass through light guide element 142. Light guide element 142 uniformizes the illumination distribution within a plane including directions D1 and D3, and the light is then emitted toward the +D2 side relative to light guide element 142. The green light LGS and LGP pass through parallelization element 162 and are parallelized by parallelization element 162. The parallelized green light LGS and LGP enter incident-side polarizing element 172 from the -D2 side. The green light LGS transmits through incident-side polarizing element 172 and is emitted toward the +D2 side relative to incident-side polarizing element 172. The green light LGP is reflected by incident surface 172a of incident-side polarizing element 172 and is emitted toward the -D2 side relative to incident-side polarizing element 172.

[0066] Green light LGP reflected from the incident-side polarizing element 172 toward the -D2 side passes through the parallelizing element 162 and the light guide element 142, travels along the D2 direction toward the -D2 side, converges within a plane encompassing the D1 and D3 directions, and enters the phosphor 124 of the light source 122 from the +D2 side. The phosphor 124 is re-excited by the green light LGP emitted from the incident-side polarizing element 172 toward the -D2 side, and emits green light LG, including green light LGS and LGP, from the emission surface 124a toward the +D2 side. The incident-side polarizing element 172 is constructed as a reflective polarizer. Therefore, the polarized portion of the green light LG that does not pass through the incident-side polarizing element 172 re-enters the phosphor 124 of the light source 122, contributing to the excitation and emission of the phosphor 124. As a result, the utilization efficiency of the green light LG in the green light emitting unit 102 and the projector 301 is improved.

[0067] The light modulator 182 is disposed on the optical path of the green light LG emitted from the incident-side polarizer 172, positioned closer to the +D2 side of the incident-side polarizer 172 and overlapping with the incident-side polarizer 172 in the D1 and D3 directions. The light modulator 182 serves as a second light modulator and modulates the green light LG emitted from the incident-side polarizer 172 based on image information transmitted from an image forming device (not shown), such as a computer, externally connected to the light modulator 182.

[0068] The light modulator 182 is, for example, a transmissive liquid crystal panel. The liquid crystal panel that constitutes the light modulator 182 has a plurality of pixels (not shown). Each pixel has a switching element. The switching element is, for example, a TFT. An electrical signal corresponding to the brightness of the green light at the relative position of each pixel on the modulation surface of the light modulator 182 in the image projected by the projector 301 is supplied to the switching element of each pixel. Each pixel modulates the vibration direction of the green light LG incident from the incident-side polarizing element 172 by the operation of the switching element corresponding to the electrical signal, thereby generating green image light IG. The image light IG corresponds to the second light. The light modulator 182 emits the image light IG generated by the liquid crystal panel along the D2 direction toward the +D2 side.

[0069] The exit-side polarizing element 176 is disposed on the optical path of the image light IG emitted from the light modulator 182, positioned closer to the +D2 side of the light modulator 182 and overlapping the light modulator 182 in the D1 and D3 directions. For example, the exit-side polarizing element 176 contacts the light modulator 182 from the +D2 side, but may also be disposed with an appropriate spacing therefrom in the D2 direction. The exit-side polarizing element 176 functions as a fifth polarizing element, emitting a predetermined polarization within the image light IG emitted from the light modulator 182 toward the +D2 side along the D2 direction. This predetermined polarization corresponds to the fifth polarization component and is, for example, P-polarized light. The exit-side polarizing element 176 is, for example, a reflective or absorptive polarizer having a plate surface parallel to a plane including the D1 and D3 directions. The exit-side polarizing element 176 transmits a portion of the incident image light IG containing the predetermined polarization toward the +D2 side and reflects the remaining portion toward the -D2 side.

[0070] like Figure 1 As shown, the red light emitting section 103 is positioned closer to the +D1 side than the green light emitting section 102 and in a region overlapping with the blue light emitting section 101 in the D2 and D3 directions. The red light emitting section 103 emits red light LR. The red light LR emitted from the red light emitting section 103 travels toward the -D1 side along the D1 direction.

[0071] The red light emitting unit 103 includes a light source 123, a light guide element 143, and a parallelizing element 163. The light source 123 is supported by the substrate 113. The light source 123 is disposed on the -D1 side of the surface of the substrate 113 that is parallel to the plane including the D2 and D3 directions. The light emitting surface of the light source 123 is arranged approximately parallel to the plane including the D2 and D3 directions and is the surface opposite in the D1 direction to the surface of the light source 123 that contacts the -D1 side of the substrate 113. The light source 123 serves as a third light source and emits red light LR in the red wavelength band within the visible wavelength range. The red wavelength band is, for example, the 610 nm to 700 nm wavelength band.

[0072] The light source 123 is composed of, for example, an LED that emits red light LR. Furthermore, the light source 123 may be composed of a single LED or a plurality of LEDs. When the light source 123 is composed of a plurality of LEDs, the plurality of LEDs are arranged in an area occupied by the light source 123 within a plane including the directions D2 and D3.

[0073] The substrate 113 is made of metal, for example, and also functions as a heat dissipating member that receives heat from the light source 123 emitting the red light LR and releases the heat to an external space.

[0074] Light guide element 143 is disposed on the optical path of red light LR emitted from light source 123, positioned closer to the -D1 side of light source 123 and overlapping with light source 123 in the D2 and D3 directions. Light guide element 143 serves as a third light guide element and includes an incident end 143a on the +D1 side of the D1 direction, an emitting end 143b on the -D1 side, and a side surface 143s and a reflecting surface 143r extending between incident end 143a and emitting end 143b in the D1 direction. Incident end 143a serves as a third incident end and extends parallel to a plane encompassing the D2 and D3 directions. The shape of incident end 143a when viewed from the D1 direction is the same as the shape of the light-emitting surface of light source 123 when viewed from the same direction, for example, a rectangle. The size of the incident end 143a within the plane containing the D2 and D3 directions can be equal to the size of the light-emitting surface of the light source 123 within the plane containing the D2 and D3 directions, but is preferably moderately larger than the size of the light-emitting surface of the light source 123 within the plane containing the D2 and D3 directions. The emitting end 143b serves as a third emitting end, extending parallel to the plane containing the D2 and D3 directions and being larger than the incident end 143a. The shape of the emitting end 143b when viewed from the D1 direction is the same as the modulation surface of the light modulator 183 when viewed from the same direction, for example, a rectangle. The size of the emitting end 143b within the plane containing the D2 and D3 directions is equal to the size of the modulation surface of the light modulator 183 within the plane containing the D2 and D3 directions. The side surface 143s and the reflective surface 143r connect the periphery of the incident end 143a and the periphery of the emitting end 143b in the D1 direction.

[0075] Red light LR emitted from light source 123 enters light guide element 143 from incident end 143a. In light guide element 143, the area enclosed by incident end 143a, emitting end 143b, and reflecting surface 143r is the region through which red light LR propagates. The size of the area enclosed by incident end 143a, emitting end 143b, and reflecting surface 143r increases within a plane encompassing directions D2 and D3 as it progresses from the +D1 side toward the -D1 side of the D1 direction. Furthermore, as it progresses from the +D1 side toward the -D1 side, the shape of the area enclosed by incident end 143a, emitting end 143b, and reflecting surface 143r within a plane encompassing directions D2 and D3 changes from the shape of the light-emitting surface of light source 123 when viewed from the D1 direction to the shape of the modulation surface of light modulator 183.

[0076] Side surface 143s of light guide element 143 and, as described later, reflective surface 143r provided on side surface 143s form a predetermined angle with respect to an imaginary line VX perpendicular to incident end 143a and the optical axis. As light moves from the +D1 side toward the -D1 side, it moves away from the imaginary line within a plane encompassing directions D2 and D3. Red light LR incident on light guide element 143 propagates from the +D1 side toward the -D1 side within the region bounded by incident end 143a, exit end 143b, and reflective surface 143r.

[0077] If the modulation surface of the light modulator 183 is rectangular when viewed along direction D1, the light-emitting surface of the light source 123 also has a rectangular shape when viewed along direction D1. In this case, the angle α formed by the side surface 143s and the reflective surface 143r, which include the short sides of the rectangle, with respect to the aforementioned imaginary line and the optical axis, is preferably within a range of 7° to 22°. The angle β formed by the side surface 143s and the reflective surface 143r, which include the long sides of the rectangle, with respect to the aforementioned imaginary line and the optical axis, is preferably within a range of 14° to 36°.

[0078] A portion of the red light LR incident on the light guide element 143 forms an angle smaller than a predetermined angle with respect to the imaginary axis and the optical axis, and thus propagates directly from the incident end 143a to the emitting end 143b without incident on the reflecting surface 143r. The remaining portion of the red light LR incident on the light guide element 143 forms an angle greater than a predetermined angle with respect to the imaginary axis and the optical axis, and is incident on the reflecting surface 143r from the incident end 143a at least once. After being reflected by the reflecting surface 143r, it reaches the emitting end 143b. The path of the red light LR within the area surrounded by the incident end 143a, the emitting end 143b, and the reflecting surface 143r varies depending on the angle of incidence on the incident end 143a, resulting in multiple paths with different numbers of reflections at the reflecting surface 143r. As a result, the illuminance distribution of red light LR propagating through the area surrounded by incident end 143a, emitting end 143b, and reflecting surface 143r is uniformed within a plane encompassing directions D2 and D3. In other words, light guide element 143 uniformizes the illuminance distribution of incident red light LR within a plane encompassing directions D2 and D3. The red light LR, with its uniform illuminance distribution, is emitted from emitting end 143b toward the -D1 side.

[0079] Like light guide elements 141 and 142, light guide element 143 is a hollow reflector formed from a plate-like member made of a transparent material such as optical glass. When viewed along direction D1, the +D1-side end of the reflector's frame has the same shape and size as incident end 143a and the light-emitting surface of light source 123, and is, for example, formed into a rectangular frame. The -D1-side end of the reflector's frame has the same shape and size as emitting end 143b and the modulation surface of light modulator 183, and is, for example, formed into a rectangular frame of a different size from the +D1-side end.

[0080] The reflector of the light guide element 143 is constructed by connecting the legs of four trapezoidal plate-like members. The lengths of the sides of the four plate-like members, corresponding to the +D1 side of the upper base and parallel to the D2 or D3 direction, are set based on the size of the incident end 143a and the light-emitting surface of the light source 123 in the D2 or D3 direction. The lengths of the sides of the four plate-like members, corresponding to the -D1 side of the lower base and parallel to the D2 or D3 direction, are set based on the size of the emitting end 143b and the modulation surface of the light modulator 183 in the D2 or D3 direction.

[0081] In the reflector of the light guide element 143, a reflective film 253 made of a dielectric multilayer film or the like is also provided on the plate surface of the plate-like member constituting the reflector opposite to the side surface 143s, i.e., on the plate surface of the plate-like member facing the interior space, in order to increase the reflectivity of the red light LR incident on the light guide element 143 from the incident end 143a near the side surface 143s. A portion of the red light LR incident on the interior space of the reflector of the light guide element 143 from the incident end 143a is reflected by the reflective film 253 and travels toward the -D1 side.

[0082] The intensity of the red light LR reflected by the reflective film 253 sometimes depends on the angle of incidence of the red light LR entering the reflective film 253. When the reflective film 253 is composed of a dielectric multilayer film, the angle of incidence dependence of the intensity of the red light LR emitted from the reflective film 253 varies depending on parameters such as the refractive index, thickness, and number of films included in the dielectric multilayer film. As described above, for example, when the angle α is in the range of 7° to 22° and the angle β is in the range of 14° to 36°, the reflective film 253 is designed so that the angle of incidence of the red light LR emitted from the reflective surface 143r and the reflective film 253, at which the intensity of the red light LR is highest, is in the range of 60° to 90°. The parameters of the dielectric multilayer film are appropriately determined. The relationship between the angle of incidence of the red light LR on the reflective film 253 and the intensity of the red light LR emitted from the reflective film 253 is also determined through numerical simulations based on the structure of the red light emitting portion 103 and ray tracing.

[0083] Parallelizer 163 is disposed on the optical path of red light LR emitted from light guide element 143, positioned closer to the -D1 side of light guide element 143 and overlapping with light guide element 143 in directions D2 and D3. Parallelizer 163 serves as a third parallizer and parallelizes the red light LR emitted from light guide element 143 along direction D1.

[0084] Parallelizer 163 is, for example, a plano-convex lens having an incident surface formed of a flat surface perpendicular to the D1 direction and an exit surface formed of a convex surface protruding toward the exit side of red light LR. The focal point of the plano-convex lens constituting parallelizer 163 is located at least on the +D1 side of parallelizer 163 and on the side opposite to the -D1 side from which red light LR is emitted from parallelizer 163, and further on the +D1 side of light guide element 143. The incident surface of parallelizer 163 contacts the exit end 143b of light guide element 143. By making parallelizer 163 contact the exit end 143b, the red light LR emitted from the exit end 143b of light guide element 143 is taken into parallelizer 163 to the greatest extent possible, thereby suppressing the loss of red light LR. However, the collimating element 163 may be an optical lens other than a plano-convex lens capable of collimating the incident red light LR, and may be disposed at an appropriate distance from the light guide element 143 in the D1 direction.

[0085] The focal length f3 of the parallelizing element 163 corresponds to the third focal length and is longer than the length g3 from the incident end 143a to the emitting end 143b of the light guide element 143 in the direction D1. The length g3 corresponds to the third length.

[0086] Although not shown, similar to the green light emitting section 102, in the red light emitting section 103, assuming that the effect of the parallelizer 163 is ignored, when the composite vector of the multiple light rays included in the red light LR emitted from the emitting end 143b toward the -D1 side is extended toward the +D1 side, the positions where the composite vectors intersect with the center lines of the parallelizer 163 and light guide element 143, as well as the optical axis, do not strictly converge at a single point, but are instead spread over a narrow area in the D1 direction. As a result, the focal point F3 of the plano-convex lens of the parallelizer 163 expands slightly in the D1 direction, but macroscopically, it forms a single point.

[0087] Since the focal length f3 of the parallelizing element 163 is set closer to + D1 than the light guide element 143 and longer than the length g3 of the light guide element 143 according to the position of the focus F3 , the multiple light beams included in the red light LR are efficiently parallelized with respect to the D1 direction.

[0088] Specifically, the focal length f3 of the parallelization element 163 is preferably at least 1.1 times the length g3 of the light guide element 143. More preferably, the focal length f3 is at least 1.1 times the length g3 and no more than 2.0 times the length g3. By setting the focal length f3 within this range, the red light LR emitted from the light source 123 is efficiently parallelized, improving the utilization efficiency of the red light LR. The preferred range of the focal length f3 was also confirmed through numerical simulations based on the structure of the red light emitting unit 103 and ray tracing.

[0089] If the focal length f3 of the parallelizer 163 is shorter than 1.1 times the length g3 of the light guide element 143, the illumination range of the red light LR emitted from the parallelizer 163 is excessively reduced. This may result in a portion of the original image not being displayed when the image light converted by the subsequent light modulator 183 is projected and magnified and displayed on the screen SC. On the other hand, if the focal length f3 is longer than 2.0 times the length g3, a portion of the red light LR emitted from the parallelizer 163 will not be incident on the light modulator 183, which is positioned further downstream than the parallelizer 163. Consequently, the utilization efficiency of the red light LR may be reduced.

[0090] The incident-side polarizing element 173 is provided on the optical path of the red light LR emitted from the parallelizing element 163. It is positioned closer to the -D1 side of the parallelizing element 163 and overlaps the parallelizing element 163 in the D2 and D3 directions. The incident-side polarizing element 173 contacts the light modulating element 183 from the +D1 side, for example. However, the incident-side polarizing element 173 may be positioned with an appropriate distance therefrom in the D1 direction.

[0091] The incident-side polarizing element 173 acts as a third polarizing element, directing a predetermined polarization of the red light LR emitted from the parallelizing element 163 toward the -D1 side along the D1 direction. This predetermined polarization corresponds to the third polarization component and is, for example, S-polarized light. The incident-side polarizing element 173 is, for example, a reflective polarizer having a plate surface parallel to a plane including the D2 and D3 directions. The incident-side polarizing element 173 transmits a portion of the incident red light LR containing the predetermined polarization toward the -D1 side, while reflecting the remaining portion toward the +D1 side.

[0092] The red light LR emitted from the light source 123 contains at least P-polarized light and S-polarized light, and is, for example, randomly polarized light. As described above, the P-polarized light component of the red light LR emitted from the light source 123 sequentially passes through the light guide element 143 and the parallelizer 163, transmits through the incident-side polarizer 173, and is emitted toward the -D1 side of the incident-side polarizer 173. The S-polarized light component of the red light LR, like the P-polarized light component, sequentially passes through the light guide element 143 and the parallelizer 163, but is reflected by the incident surface of the incident-side polarizer 173 and is emitted toward the +D1 side of the incident-side polarizer 173.

[0093] The light modulator 183 is disposed on the optical path of the red light LR emitted from the incident-side polarizer 173, positioned closer to the -D1 side of the incident-side polarizer 173 and overlapping with the incident-side polarizer 173 in the D2 and D3 directions. The light modulator 183 functions as a third light modulator and modulates the red light LR emitted from the incident-side polarizer 173 based on image information transmitted from an image forming device (not shown), such as a computer, externally connected to the light modulator 183.

[0094] The light modulator 183 is, for example, a transmissive liquid crystal panel. The liquid crystal panel that constitutes the light modulator 183 has a plurality of pixels (not shown). Each pixel has a switching element. The switching element is, for example, a TFT. An electrical signal corresponding to the brightness of red light at the relative position of each pixel on the modulation surface of the light modulator 183 in the image projected by the projector 301 is supplied to the switching element of each pixel. Each pixel modulates the vibration direction of the red light LR incident from the incident-side polarizing element 173 by the operation of the switching element corresponding to the electrical signal, thereby generating red image light IR. The image light IR corresponds to the third light. The light modulator 183 emits the image light IR generated by the liquid crystal panel along the D1 direction toward the -D1 side.

[0095] The output-side polarizing element 177 is disposed on the optical path of the image light IR emitted from the light modulator 183, positioned closer to the -D1 side of the light modulator 183 and overlapping the light modulator 183 in the D2 and D3 directions. For example, the output-side polarizing element 177 contacts the light modulator 183 from the -D1 side, but may also be disposed with an appropriate spacing therefrom in the D1 direction. The output-side polarizing element 177 functions as a sixth polarizing element, emitting a predetermined polarization within the image light IR emitted from the light modulator 183 toward the -D1 side along the D1 direction. This predetermined polarization corresponds to the sixth polarization component, for example, P-polarization. The output-side polarizing element 177 is, for example, a reflective or absorptive polarizer having a plate surface parallel to a plane including the D2 and D3 directions. The output-side polarizing element 177 transmits a portion of the incident image light IR containing the predetermined polarization toward the -D1 side, while reflecting the remaining portion of the green light LG toward the +D1 side.

[0096] The photosynthesizer 200 is disposed in a region where the optical path of the blue image light IB emitted from the emission-side polarizing element 175, the optical path of the green image light IG emitted from the emission-side polarizing element 176, and the optical path of the red image light IR emitted from the emission-side polarizing element 177 intersect. The photosynthesizer 200 combines the image light IB, IG, and IR emitted from the emission-side polarizing elements 175, 176, and 177, and emits the combined image light IB, IG, and IR along the D2 direction toward the +D2 side.

[0097] The photosynthesizing element 200 is, for example, a cross dichroic prism 210. The cross dichroic prism 210 includes an incident surface 210c facing the exit surface of the exit-side polarizing element 175, an incident surface 210d facing the exit surface of the exit-side polarizing element 176, an incident surface 210e facing the exit surface of the exit-side polarizing element 177, an exit surface 210b, and two reflective films 211 and 212. The incident surfaces 210c and 210e are parallel to a plane including the D2 and D3 directions and overlap with each other in the D2 and D3 directions. The incident surface 210d and the exit surface 210b are parallel to a plane including the D1 and D3 directions and overlap with each other in the D1 and D3 directions.

[0098] When viewed along the D3 direction, the reflective film 211 is arranged so that it moves from the +D2 side to the -D2 side as it moves from the -D1 side to the +D1 side. When viewed along the D3 direction, the reflective film 212 is arranged so that it moves from the -D2 side to the +D2 side as it moves from the -D1 side to the +D1 side. The reflective films 211 and 212 overlap with the incident surfaces 210c and 210e in the D2 direction and with the exit surface 210b and incident surface 210d in the D3 direction. The reflective film 211 reflects light in the blue wavelength range and transmits light in the green and red wavelength ranges. The reflective film 212 reflects light in the red wavelength range and transmits light in the blue and green wavelength ranges.

[0099] The cross dichroic prism 210 is constructed such that, when viewed from the D3 direction, the four right-angle prisms align their right-angled vertices with the center of the photosynthesizing element 200, and their right-angled surfaces are in contact with each other. The four right-angle prisms of the cross dichroic prism 210 are formed from a transparent material that transmits light in the visible wavelength range. A reflective film 211 is disposed on one of the right-angled surfaces of the four right-angle prisms, such as that which moves from the +D2 side to the -D2 side as it moves from the -D1 side to the +D1 side, as described above. It is composed, for example, of a dielectric multilayer film. A reflective film 212 is disposed on one of the right-angled surfaces of the four right-angle prisms, such as that which moves from the -D2 side to the +D2 side as it moves from the -D1 side to the +D1 side, as described above.

[0100] The blue image light IB (P-polarized light) emitted from the output-side polarizing element 175 enters the cross dichroic prism 210 from the incident surface 210c along the D1 direction toward the +D1 side, passes through the reflective film 211, is reflected by the reflective film 212, and travels toward the +D2 side. The green image light IG (P-polarized light) emitted from the output-side polarizing element 176 enters the cross dichroic prism 210 from the incident surface 210d along the D2 direction toward the +D2 side, passes through the reflective films 211 and 212, and travels straight toward the +D2 side. The red image light IR (P-polarized light) emitted from the output-side polarizing element 177 enters the cross dichroic prism 210 from the incident surface 210e along the D1 direction toward the -D1 side, passes through the reflective film 212, is reflected by the reflective film 211, and travels toward the +D2 side. The image lights IB, IG, and IR emitted toward the +D2 side from the reflection films 211 and 212 of the cross dichroic prism 210 are combined to generate full-color image light IM. The cross dichroic prism 210 emits full-color image light IM toward the +D2 side along the D2 direction from the emission surface 210b.

[0101] The projection optical system 250 is arranged on the optical path of the image light IM emitted from the photosynthesizing element 200. The projection optical system 250 projects the image light IM emitted from the projection optical system 250 onto the screen SC arranged on the +D2 side, and enlarges and displays the image sent from the image forming device to the light modulating elements 181, 182, and 183 on the screen SC.

[0102] The projection optical system 250 is composed of, for example, one or more optical lenses arranged along the D2 direction. Examples of the optical lenses include plano-convex lenses, plano-concave lenses, biconvex lenses, biconcave lenses, meniscus lenses, aspherical lenses, and free-form surface lenses.

[0103] The projector 301 of the present embodiment described above includes a light source (first light source) 121, a light source (second light source) 122, a light source (third light source) 123, a light guide element (first light guide element) 141, a light guide element (second light guide element) 142, a light guide element (third light guide element) 143, a parallelizer (first parallelizer) 161, a parallelizer (second parallelizer) 162, a parallelizer (third parallelizer) 163, a light modulator (first light modulator) 181, a light modulator (second light modulator) 182, a light modulator (third light modulator) 183, a photosynthesizer 200, and a projection optical system 250. The light source 121 emits blue light (first light) LB in a blue wavelength band (first wavelength band). The light source 122 emits green light (second light) LG in a green wavelength band (second wavelength band) different from the blue wavelength band. Light source 123 emits red light (third light) LR in a red wavelength band (third wavelength band) different from the blue and green wavelength bands. Light guide element 141 has an incident end (first incident end) 141a for the blue light LB emitted from light source 121 to enter, and an exit end (first exit end) 141b for emitting the blue light LB. This arrangement uniformizes the illuminance (in-plane illuminance) within a plane encompassing the D2 and D3 directions of the blue light LB. Light guide element 142 has an incident end (second incident end) 142a for the green light LG emitted from light source 122 to enter, and an exit end (second exit end) 142b for emitting the green light LG. This arrangement uniformizes the illuminance (in-plane illuminance) within a plane encompassing the D1 and D3 directions of the green light LG. The light guide element 143 has an incident end (third incident end) 143a for the red light LR emitted from the light source 123 to enter, and an exit end (third exit end) 143b for emitting the red light LR. This makes the illuminance (in-plane illuminance) of the red light LR uniform within a plane including the directions D1 and D3. The light modulator (first light modulator) 181 modulates the blue light LB emitted from the parallelizing element 161 according to image information. The light modulator (second light modulator) 182 modulates the green light LG emitted from the parallelizing element 162 according to image information. The light modulator (third light modulator) 183 modulates the red light LR emitted from the parallelizing element 163 according to image information. The photosynthesizer 200 synthesizes the image light (first light) IB emitted from the light modulator 181, the image light (second light) IG emitted from the light modulator 182, and the image light (third light) IR emitted from the light modulator 183, and emits them. The projection optical system 250 projects image light (light) IM emitted from the photosynthesizing element 200. In the projector 301 of this embodiment, the focal length (first focal length) f1 of the parallelizing element 161 is longer than the length (first length) g1 in the direction D1 from the incident end 141a to the emitting end 141b of the light guide element 141.The focal length (second focal length) f2 of the parallelizing element 162 is longer than the length (second length) g2 in the direction D2 from the incident end 142a to the emitting end 142b of the light guide element 142. The focal length (third focal length) f3 of the parallelizing element 163 is longer than the length (third length) g3 in the direction D1 from the incident end 143a to the emitting end 143b of the light guide element 143.

[0104] In projector 301 of this embodiment, the three colored lights emitted from light sources 121, 122, and 123—blue light LB, green light LG, and red light LR—are directly converted into image lights IB, IG, and IR by light modulators 181, 182, and 183. The image lights IB, IG, and IR are then combined by light synthesizer 200, and the resulting full-color image light IM is projected. Conventional projectors, on the other hand, generate white light, separate it into three colored lights using color separation elements or a color separation optical system, convert each color light into image light using light modulators, and combine the image light into full-color image light using a light synthesizer, which then projects the full-color image light. In projector 301 of this embodiment, the color synthesizer and color synthesis optical system for combining the three colored lights into white light, as well as the color separation element and color separation optical system for separating white light into three colored lights, are eliminated before the light modulators corresponding to the three colored lights. This reduces the number of components, the number of devices, and the overall size compared to conventional projectors. According to the projector 301 of this embodiment, it is possible to achieve miniaturization compared to conventional projectors.

[0105] In the projector 301 of this embodiment, the focal length f1 of the parallelization element 161 is longer than the length g1 of the light-guiding element 141, the focal length f2 of the parallelization element 162 is longer than the length g2 of the light-guiding element 142, and the focal length f3 of the parallelization element 163 is longer than the length g3 of the light-guiding element 143. Therefore, the parallelism of the blue light LB, green light LG and red light LR emitted from the light-guiding elements 141, 142 and 143 can be improved, so that these colored lights are efficiently incident on the parallelization elements 161, 162 and 163, thereby improving the utilization efficiency of the colored lights.

[0106] In the projector 301 of this embodiment, the cross-section of the light guide elements 141 and 143 perpendicular to the optical axis and the direction D1 is rectangular, and the cross-section of the light guide element 142 perpendicular to the optical axis and the direction D2 is rectangular.

[0107] In the projector 301 of this embodiment, rectangular blue light LB, green light LG, and red light LR with uniform illumination can be easily generated within a plane perpendicular to the optical axis of the colored light by the light guide elements 141, 142, and 143. According to the projector 301 of this embodiment, colored light that conforms to the rectangular modulation surfaces of the light modulator elements 181, 182, and 183 can be easily generated.

[0108] The projector 301 of this embodiment further includes an incident-side polarization element (first polarization element) 171, an incident-side polarization element (second polarization element) 172, and an incident-side polarization element (third polarization element) 173. The incident-side polarization element 171 is disposed between the parallelizer 161 and the light modulator 181, and transmits a portion of the blue light LB having the S-polarized light component (first polarization component) while reflecting the other portion of the blue light LB, namely the P-polarized light component. In the projector 301 of this embodiment, the incident-side polarization element 172 is disposed between the parallelizer 162 and the light modulator 182, and transmits a portion of the green light LG having the S-polarized light component (second polarization component) while reflecting the other portion of the green light LG, namely the P-polarized light component. The incident-side polarization element 173 is disposed between the parallelizer 163 and the light modulator 183, and transmits a portion of the red light LR having the S-polarized light component (third polarization component) while reflecting the other portion of the red light LR, namely the P-polarized light component. In projector 301 of this embodiment, another portion of blue light LB enters light guide element 141 and travels toward light source 121. Another portion of green light LG enters light guide element 142 and travels toward light source 122. Another portion of red light LR enters light guide element 143 and travels toward light source 123.

[0109] In the projector 301 of this embodiment, another portion of each of the blue light LB, green light LG, and red light LR reflected by the incident-side polarizing elements 171, 172, and 173 and emitted from the incident-side polarizing elements 171, 172, and 173 can be incident on the light sources 121, 122, and 123. If, for example, light source 122 includes a phosphor 124, another portion of the green light LG directed toward light source 122 is incident on phosphor 124, contributing to the excitation of phosphor 124. Furthermore, if the substrates 111, 112, and 113 of the light sources 121, 122, and 123 are reflective, another portion of each of the blue light LB, green light LG, and red light LR directed toward the light sources 121, 122, and 123 is reflected by the substrates 111, 112, and 113, and is again incident on the light guide elements 141, 142, and 143, where it is utilized. According to the projector 301 of this embodiment, another part of the blue light LB, green light LG and red light LR reflected by the incident side polarization elements 171, 172, 173 is again incident on the light guiding elements 141, 142, 143, thereby improving the utilization efficiency of the blue light LB, green light LG and red light LR.

[0110] In the projector 301 of this embodiment, the cross-sectional area of ​​the emitting end 141b of the light guide element 141, which includes the directions D2 and D3, is larger than the cross-sectional area of ​​the incident end 141a of the light guide element 141. The cross-sectional area of ​​the emitting end 142b of the light guide element 142, which includes the directions D1 and D3, is larger than the cross-sectional area of ​​the incident end 142a of the light guide element 142. The cross-sectional area of ​​the emitting end 143b of the light guide element 143, which includes the directions D2 and D3, is larger than the cross-sectional area of ​​the incident end 143a of the light guide element 143.

[0111] Figure 4 1 is a schematic diagram of the green light emitting unit 102, the incident side polarizing element 172 and the light modulating element 182 as an example. Figure 3 and Figure 4 In the embodiment, as a modified example of the projector 301 of this embodiment, in the direction D2, the incident side polarization element 172 is spaced apart from the parallelization element 162, and the light modulation element 182 is spaced apart from the incident side polarization element 172. Figure 4As shown above, for example, the width w142A of the incident end 142a of the light guide element 142 in the D1 direction is set based on the width w122 of the light emitting surface 122a of the light source 122 in the D1 direction. The width w142B of the emitting end 142b of the light guide element 142 in the D1 direction is greater than the width w142A of the incident end 142a. Although not shown, the width and cross-sectional area of ​​the emitting end 142b of the light guide element 142 in the D2 direction are greater than the width and cross-sectional area of ​​the incident end 142a in the D2 direction.

[0112] In projector 301 of this embodiment, the illuminance distribution of blue light LB, green light LG, and red light LR is uniformized before entering from incident ends 141a, 142a, and 143a of light guide elements 141, 142, and 143 and exiting from exit ends 141b, 142b, and 143b, thereby expanding the irradiation area of ​​each color light. According to projector 301 of this embodiment, the size of blue light LB, green light LG, and red light LR emitted from light sources 121, 122, and 123, whose light emitting surfaces are smaller than the modulation surfaces of the light modulators 181, 182, and 183, on a plane perpendicular to the optical axis, i.e., the irradiation area, can be easily expanded in accordance with the modulation surfaces of the light modulators 181, 182, and 183.

[0113] In projector 301 of this embodiment, the length from incident end 141a to emission end 141b of light guide element 141 is greater than or equal to 8 mm and less than or equal to 25 mm. The length from incident end 142a to emission end of light guide element 142 is greater than or equal to 8 mm and less than or equal to 25 mm. The length from incident end 143a to emission end 143b of light guide element 143 is greater than or equal to 8 mm and less than or equal to 25 mm.

[0114] According to the projector 301 of this embodiment, the extraction efficiency of the blue light LB, green light LG, and red light LR by the light guide elements 141 , 142 , and 143 can be improved, and the illuminance distribution of the blue light LB, green light LG, and red light LR can be made uniform.

[0115] In the projector 301 of this embodiment, with respect to the length g1 of the light guide element 141 and the focal length f1 of the parallelizer 161, 1.1×g1≤f1≤2.0×g1 is satisfied. With respect to the length g2 of the light guide element 142 and the focal length f2 of the parallelizer 162, 1.1×g2≤f2≤2.0×g2 is satisfied. With respect to the length g3 of the light guide element 143 and the focal length f3 of the parallelizer 163, 1.1×g3≤f3≤2.0×g3 is satisfied.

[0116] According to the projector 301 of this embodiment, the blue light LB, green light LG and red light LR emitted from the light guide elements 141, 142 and 143 can be more efficiently incident on the parallelization elements 161, 162 and 163, thereby improving the utilization efficiency of the blue light LB, green light LG and red light LR.

[0117] In the projector 301 of this embodiment, the focal point F1 of the parallelizing element 161 is located on the -D1 side of the light source 121, that is, on the side opposite to the emission side of the blue light LB of the light source 121. The focal point F2 of the parallelizing element 162 is located on the -D2 side of the light source 122, that is, on the side opposite to the emission side of the green light LG of the light source 122. The focal point F3 of the parallelizing element 163 is located on the +D1 side of the light source 123, that is, on the side opposite to the emission side of the red light LR of the light source 123.

[0118] According to the projector 301 of this embodiment, the blue light LB, green light LG and red light LR emitted from the light guide elements 141, 142, and 143 can be efficiently incident on the parallelization elements 161, 162, and 163, thereby improving the utilization efficiency of the blue light LB, green light LG and red light LR.

[0119] In the projector 301 of this embodiment, when the length g1 of the light-guiding element 141 is set to 1, the distance between the position of the focus F1 of the parallelizing element 161 in the direction D1 and the light emitting surface (light emitting surface) 122a of the light source 122 emitting the blue light LB is greater than 0.1 and less than 0.5. When the length g2 of the light-guiding element 142 is set to 1, the distance between the position of the focus F2 of the parallelizing element 162 in the direction D2 and the light emitting surface (light emitting surface) 122a of the light source 122 emitting the green light LG is greater than 0.1 and less than 0.5. Figure 2 When the length g3 of the light guide element 143 is set to 1, the distance between the position of the focus F3 of the parallelizing element 163 and the light emitting surface of the light source 123 emitting the red light LR in the direction D1 is greater than or equal to 0.1 and less than or equal to 0.5.

[0120] According to the projector 301 of this embodiment, the blue light LB, green light LG, and red light LR that are not blocked by the parallelizing elements 161 , 162 , and 163 and are taken in can be reduced, thereby improving the utilization efficiency of the blue light LB, green light LG, and red light LR.

[0121] In the projector 301 of this embodiment, the light guide elements 141 , 142 , and 143 are made of glass such as optical glass or metallic glass.

[0122] In the projector 301 of this embodiment, as described above, the light guide elements 141, 142, and 143 are plate-shaped members made of a transparent material including glass such as optical glass.

[0123] As a variation of the projector 301 of this embodiment, the plate-like components that comprise the light guide elements 141, 142, and 143 may also be made of metal. That is, the reflectors of the light guide elements 141, 142, and 143 may also be made of a plate-like component made of a reflective material, such as a metal material, that reflects blue light LB, green light LG, and red light LR. In this case, similar to the case where a reflective film is provided on the surface of the plate-like component that faces the interior space of the reflector, which is made of a transparent material, the surface of the plate-like component that faces the interior space of the reflector functions as the reflective surfaces 141r, 142r, and 143r. A portion of the blue light LB, green light LG, and red light LR that enter the interior space of the reflector of the light guide elements 141, 142, and 143 from the incident ends 141a, 142a, and 143a is reflected by the surface of the plate-like component that faces the interior space of the reflector and travels along the optical axis. In the modified example of the projector 301 of the present embodiment, the heat dissipation and heat resistance of the light guide elements 141 , 142 , and 143 can also be improved.

[0124] In the projector 301 of this embodiment, the light guide elements 141 , 142 , 143 are hollow, and reflective films 251 , 252 , 253 are provided on surfaces (inner surfaces) of the plate-like members constituting the light guide elements 141 , 142 , 143 that face the inner space.

[0125] In projector 301 of this embodiment, a portion of each of blue light LB, green light LG, and red light LR incident on light guide elements 141, 142, and 143 is specularly reflected by reflective films 251, 252, and 253, and propagates within the internal spaces of light guide elements 141, 142, and 143. According to projector 301 of this embodiment, the loss of blue light LB, green light LG, and red light LR within light guide elements 141, 142, and 143 can be reduced.

[0126] As another variation of the projector 301 of this embodiment, the light guide elements 141, 142, and 143 may be solid and made of a transparent material such as optical glass. In this case, the external-facing surfaces of the reflectors of the light guide elements 141, 142, and 143, namely the side surfaces 141s, 142s, and 143s, function as reflective surfaces 141r, 142r, and 143r. A portion of the blue light LB, green light LG, and red light LR incident on the reflectors of the light guide elements 141, 142, and 143 from the incident ends 141a, 142a, and 143a is totally reflected by the reflective surfaces 141r, 142r, and 143r of the reflectors, traveling along the optical axis. Alternatively, the light guide elements 141, 142, and 143 may be solid and made of a transparent material such as optical glass, and reflective films 251, 252, and 253 may be provided on the side surfaces 141s, 142s, and 143s. In other variations of the projector 301 of this embodiment, the loss of blue light LB, green light LG, and red light LR within the light guide elements 141, 142, and 143 can also be reduced.

[0127] In the projector 301 of this embodiment, when viewed along the optical axis of the parallelizer 161, that is, when the parallelizer 161 is viewed along the D1 direction, the parallelizer 161 covers the emission end 141b of the light guide element 141 from the +D1 side. When viewed along the optical axis of the parallelizer 162, that is, when the parallelizer 162 is viewed along the D2 direction, the parallelizer 162 covers the emission end 142b of the light guide element 142 from the +D2 side. When viewed along the optical axis of the parallelizer 163, that is, when the parallelizer 163 is viewed along the D1 direction, the parallelizer 163 covers the emission end 143b of the light guide element 143 from the -D1 side.

[0128] According to the projector 301 of this embodiment, the blue light LB, green light LG and red light LR emitted from the emission ends 141b, 142b, 143b of the light-guiding elements 141, 142, 143 but not blocked and taken in by the parallelization elements 161, 162, 163 can be reduced, and the utilization efficiency of the blue light LB, green light LG and red light LR can be improved.

[0129] As another variation of the projector 301 of this embodiment, the light guiding elements 141, 142, and 143 may be hollow, at least a portion of the parallelization element 161 may be housed in the light guiding element 141, at least a portion of the parallelization element 162 may be housed in the light guiding element 142, and at least a portion of the parallelization element 163 may be housed in the light guiding element 143.

[0130] In the above-mentioned variation of the projector 301 of this embodiment, the parallelization elements 161, 162, and 163 can also be composed of a plano-convex lens having a flat surface and a convex surface protruding toward the incident side of the blue light LB, the green light LG, and the red light LR, or a double convex lens having convex surfaces protruding toward the incident side and the emitting side of the blue light LB, the green light LG, and the red light LR.

[0131] Figure 5 and Figure 6 FIG. 1 is a schematic diagram of the green light emitting unit 102 in another modified example of the projector 301 of this embodiment. Figure 5 In the modified example shown, a light guide element 146 is provided instead of the light guide element 142. The light guide element 146 is solid and formed of a transparent material. Figure 5 In the modified example shown, the emission end 142b of the light guide element 146 is formed of a convex surface that protrudes toward the -D2 side, that is, the incident side of the green light LG. Figure 5 In the modified example shown, a parallelizing element 166 is provided instead of the parallelizing element 162. The parallelizing element 166 is a plano-convex lens having: an incident surface 166a consisting of a convex surface protruding toward the -D2 side, i.e., the incident side of the green light LG; and an exit surface 166b parallel to the plane including the D1 direction and the D3 direction. The incident surface 166a of the parallelizing element 166 contacts the exit end 146b on the opposite side of the incident end 146a of the light-guiding element 146 in the D2 direction, and is substantially configured in the same manner as in the state in which a portion of the incident side of the green light LG in the parallelizing element 166 is housed in the light-guiding element 146. According to Figure 5 The modified example shown can efficiently capture the green light LG emitted from the emission end 146b of the light guide element 146 into the parallelizing element 166, minimize the green light LG not blocked by the parallelizing element 166 and captured, and improve the utilization efficiency of the green light LG. Figure 5 The structure shown can be applied to the blue light emitting section 101 and the red light emitting section 103 of the projector 301 of this embodiment.

[0132] exist Figure 6 In the modified example shown, the light guide element 142 is hollow, and a parallelizing element 166 is provided instead of the parallelizing element 162. A portion of the incident side of the green light LG in the parallelizing element 166 is accommodated in the internal space of the light guide element 142. Figure 6 The modified example shown can efficiently take the green light LG emitted from the emission end 142b of the light guide element 142 on the -D2 side into the parallelizing element 166, minimize the green light LG that is not blocked by the parallelizing element 166 and taken in, and improve the utilization efficiency of the green light LG. Figure 6The illustrated structure can also be applied to the blue light emitting section 101 and the red light emitting section 103 of the projector 301 of this embodiment.

[0133] As another modified example of the projector 301 of this embodiment, the incident-side polarization element (first polarization element) of the blue light emitting section 101 may be fixed to the parallelizing element 161. The incident-side polarization element (second polarization element) of the green light emitting section 102 may be fixed to the parallelizing element 162. The incident-side polarization element (third polarization element) of the red light emitting section 103 may be fixed to the parallelizing element 163.

[0134] Figure 7 and Figure 8 : is a schematic diagram of the green light emitting unit 102 in the above-mentioned modification of the projector 301 of this embodiment. Figure 7 In the modified example shown, an incident-side polarizing element (second polarizing element) 272 is provided instead of the incident-side polarizing element 172. The incident-side polarizing element 272 is a reflective polarizing layer or polarizing film having the same function and effect as the incident-side polarizing element 172. The incident-side polarizing element 272 is fixed to the parallelizing element 162 by being formed on the emission surface 162b of the parallelizing element 162. Figure 7 The modified example shown can eliminate the space between the parallelizing element 162 and the incident-side polarizing element 272, thereby suppressing the increase in size of the green light emitting unit 102 and the projector 301. Figure 7 In the modified example shown, no interface is generated between the air outside the parallelizing element 162 and the incident-side polarizing element 272 , and thus the loss of the green light LG can be minimized, thereby improving the utilization efficiency of the green light LG. Figure 7 The illustrated structure can also be applied to the blue light emitting section 101 and the red light emitting section 103 of the projector 301 of this embodiment.

[0135] exist Figure 8 In the modified example shown, Figure 5 The structure shown in FIG. 1 is provided with an incident-side polarizing element 272. The incident-side polarizing element 272 is fixed to the parallelizing element 166 by being formed on the flat emission surface 166b of the parallelizing element 166. Figure 8 In the modified example shown, the space between the parallelizing element 166 and the incident-side polarizing element 272 can also be eliminated, and the size increase of the green light emitting unit 102 and the projector 301 can be suppressed. Figure 7 In the modified example shown, no interface is generated between the air outside the parallelizing element 166 and the incident-side polarizing element 272 , and thus the loss of the green light LG can be minimized, thereby improving the utilization efficiency of the green light LG. Figure 8The illustrated structure can also be applied to the blue light emitting section 101 and the red light emitting section 103 of the projector 301 of this embodiment.

[0136] Figure 9 It is a schematic diagram of the light source 122 and the light guide element 142 of the green light emitting portion 102. In the projector 301 of this embodiment, the cross-sectional shape of the light guide elements 141, 142, 143 is a rectangle. When the inclination angle of the side surface including the short side of the light guide elements 141, 142, 143, that is, the angle relative to the optical axis is α, 7°≤α≤22°. When the inclination angle of the side surface including the long side of the light guide elements 141, 142, 143 is β, 14°≤β≤36°. Reflective films 251, 252, 253 are provided on the surface (inner surface) of the plate-like parts of the hollow light guide elements 141, 142, 143 facing the internal space. As Figure 9 As shown in the example, when the reflectivity of the blue light LB, the green light LG, and the red light LR of the reflective films 251, 252, and 253 is the highest, the incident angle of the light incident on the reflective films 251, 252, and 253 is θ in When 60°≤θ in ≤90°.

[0137] In projector 301 of this embodiment, light emitted from light sources 121, 122, and 123 enters light guide elements 141, 142, and 143 radially at a predetermined angle relative to the optical axis from incident ends 141a, 142a, and 143a. By designing reflective films 251, 252, and 253 as described above, the intensities of blue light LB, green light LG, and red light LR reflected by reflective films 251, 252, and 253 are increased. Projector 301 of this embodiment minimizes the loss of blue light LB, green light LG, and red light LR in light guide elements 141, 142, and 143, thereby improving the utilization efficiency of blue light LB, green light LG, and red light LR.

[0138] The projector 301 of this embodiment further includes an output-side polarization element (fourth polarization element) 175, an output-side polarization element (fifth polarization element) 176, and an output-side polarization element (sixth polarization element) 177. The output-side polarization element 175 is disposed between the light modulator 181 and the photosynthesizer 200. It transmits a portion of the image light (light) IB emitted from the light modulator 181 that has a P-polarized light component (fourth polarization component), while absorbing the rest of the image light IB. The output-side polarization element 176 is disposed between the light modulator 182 and the photosynthesizer 200. It transmits a portion of the image light (light) IG emitted from the light modulator 182 that has a P-polarized light component (fifth polarization component), while absorbing the rest of the image light IG. The emitting side polarization element 177 is arranged between the light modulator 183 and the photosynthetic element 200, allowing a part of the image light (light) IR emitted from the light modulator to pass through that has the P polarized light component (sixth polarized light component), and absorbing the other part of the image light IR except the P polarized light component.

[0139] In the projector 301 of this embodiment, the P-polarized light component in the image light IB, IG, IR is made incident on the photosynthetic element 200 through the output-side polarization elements 175, 176, 177, for example, which are composed of an absorption-type polarizer or polarization element, and the other part of the image light IB, IG, IR other than the P-polarized light component is absorbed, thereby suppressing the return light and stray light to the light modulation elements 181, 182, 183 caused by the other part of the image light IB, IG, IR.

[0140] As mentioned above, although the preferred embodiment of the present invention was described in detail, the present invention is not limited to the specific embodiment, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

[0141] In the blue light emitting section 101 or the red light emitting section 103, for example, similar to the green light emitting section 102, the LEDs constituting the light sources 121 and 123 may include phosphors that are excited by light from the LED body to emit blue light LB and red light LR. Alternatively, the LED constituting the light source 122 of the green light emitting section 102 may not include the phosphor 124, and light source 122 may be an LED that directly emits green light LG. Furthermore, the polarization components transmitted by the incident-side polarizers arranged in the optical paths of the respective colored lights may or may not be the same.

[0142] [Summary of the present disclosure]

[0143] The following is a summary of the present disclosure.

[0144] (Note 1)

[0145] A projector comprising: a first light source emitting first light of a first wavelength band; a second light source emitting second light of a second wavelength band different from the first wavelength band; a third light source emitting third light of a third wavelength band different from the first wavelength band and the second wavelength band; a first light guide element having a first incident end for the first light emitted from the first light source to be incident and a first exit end for emitting the first light, so as to make the in-plane illuminance of the first light uniform; a second light guide element having a second incident end for the second light emitted from the second light source to be incident and a second exit end for emitting the second light, so as to make the in-plane illuminance of the second light uniform; a third light guide element having a third incident end for the third light emitted from the third light source to be incident and a third exit end for emitting the third light, so as to make the in-plane illuminance of the third light uniform; a first parallelizing element for parallelizing the first light emitted from the first light guide element; a second parallelizing element for parallelizing the second light emitted from the second light guide element; a third parallelizing element, It parallelizes the third light emitted from the third light-guiding element; a first light modulating element, which modulates the first light emitted from the first parallelizing element based on image information; a second light modulating element, which modulates the second light emitted from the second parallelizing element based on image information; a third light modulating element, which modulates the third light emitted from the third parallelizing element based on image information; a photosynthetic element, which synthesizes the first light emitted from the first light modulating element, the second light emitted from the second light modulating element, and the third light emitted from the third light modulating element and emits them; and a projection optical system, which projects the light emitted from the photosynthetic element, the first focal length of the first parallelizing element is longer than the first length from the first incident end to the first emission end, the second focal length of the second parallelizing element is longer than the second length from the second incident end to the second emission end, and the third focal length of the third parallelizing element is longer than the third length from the third incident end to the third emission end.

[0146] According to the configuration of Supplementary Note 1, optical components for generating white light and optical components for separating light for each color are unnecessary, so the number of components is small, and the size of a three-panel projector can be suppressed, thereby realizing a compact projector.

[0147] (Supplementary Note 2) The projector according to Supplementary Note 1, wherein the cross-sectional shape of the first light guide element is rectangular, the cross-sectional shape of the second light guide element is rectangular, and the cross-sectional shape of the third light guide element is rectangular.

[0148] According to the configuration of Supplementary Note 2, rectangular illumination light with a uniform illuminance distribution can be easily generated.

[0149] (Note 3) The projector according to Note 1 or 2, wherein the projector comprises: a first polarizing element, which is arranged between the first parallelizing element and the first light modulating element, so that a part of the first light having the first polarized light component passes through and another part is reflected; a second polarizing element, which is arranged between the second parallelizing element and the second light modulating element, so that a part of the second light having the second polarized light component passes through and another part is reflected; and a third polarizing element, which is arranged between the third parallelizing element and the third light modulating element, so that a part of the third light having the third polarized light component passes through and another part is reflected, another part of the first light is incident on the first light guiding element, another part of the second light is incident on the second light guiding element, and another part of the third light is incident on the third light guiding element.

[0150] According to the structure of Note 3, the first light, second light and third light reflected by the first polarization element, the second polarization element and the third polarization element can be incident on the first light guide element, the second light guide element and the third light guide element again, thereby improving the utilization efficiency of the first light, the second light and the third light.

[0151] (Note 4) The projector according to any one of Notes 1 to 3, wherein the cross-sectional area of ​​the first emission end is larger than the cross-sectional area of ​​the first incident end, the cross-sectional area of ​​the second emission end is larger than the cross-sectional area of ​​the second incident end, and the cross-sectional area of ​​the third emission end is larger than the cross-sectional area of ​​the third incident end.

[0152] According to the structure of Note 4, the size of the irradiation area of ​​the first light, the second light and the third light emitted from the first light source, the second light source and the third light source can be made consistent with the size of the modulation surface of the first light modulator, the second light modulator and the third light modulator, and the illumination distribution of the first light, the second light and the third light can be uniformly expanded.

[0153] (Note 5) A projector according to any one of Notes 1 to 4, wherein a first length from the first incident end to the first emission end is greater than 8 mm and less than 25 mm, a second length from the second incident end to the second emission end is greater than 8 mm and less than 25 mm, and a third length from the third incident end to the third emission end is greater than 8 mm and less than 25 mm.

[0154] According to the configuration of Supplementary Note 5, the extraction efficiency of the first light, the second light, and the third light can be improved, and the first light, the second light, and the third light can be well uniformed.

[0155] (Note 6) A projector according to any one of Notes 1 to 5, wherein, when the first length is g1 and the first focal length is f1, 1.1×g1≤f1≤2.0×g1, when the second length is g2 and the second focal length is f2, 1.1×g2≤f2≤2.0×g2, and when the third length is g3 and the third focal length is f3, 1.1×g3≤f3≤2.0×g3.

[0156] In the structure of Note 6, the first light, the second light and the third light emitted from the first light guide element, the second light guide element and the third light guide element can be efficiently incident on the first parallelization element, the second parallelization element and the third parallelization element, thereby improving the utilization efficiency of the first light, the second light and the third light and realizing the miniaturization of the projector.

[0157] (Note 7) A projector according to any one of Notes 1 to 6, wherein the focus of the first parallelization element is located on the side of the first light source opposite to the emission side of the first light, the focus of the second parallelization element is located on the side of the second light source opposite to the emission side of the second light, and the focus of the third parallelization element is located on the side of the third light source opposite to the emission side of the third light.

[0158] In the structure of Note 7, the focal lengths of the first, second and third parallelizing elements can be appropriately arranged on the incident side of light, thereby improving the utilization efficiency of the first, second and third lights and achieving miniaturization of the projector.

[0159] (Note 8) A projector according to any one of Notes 1 to 7, wherein, when the first length is set to 1, the distance between the position of the focus of the first parallelization element and the light emitting surface of the first light source emitting the first light is greater than 0.1 and less than 0.5.

[0160] In the configuration of Supplementary Note 8, the utilization efficiency of the first light, the second light, and the third light can be improved, thereby achieving miniaturization of the projector.

[0161] (Supplementary Note 9) The projector according to any one of Supplementary Notes 1 to 8, wherein the first light guide element, the second light guide element, and the third light guide element are made of glass or metal.

[0162] In the structure of Supplementary Note 9, the heat dissipation and heat resistance of the first light guide element, the second light guide element, and the third light guide element can be improved.

[0163] (Supplementary Note 10) The projector according to any one of Supplementary Notes 1 to 9, wherein the first light guide element, the second light guide element and the third light guide element are hollow, and a reflective film is provided on the inner side surfaces of the first light guide element, the second light guide element and the third light guide element.

[0164] In the structure of Supplementary Note 10 , the loss of the first light, the second light, and the third light generated in the first light guide element, the second light guide element, and the third light guide element can be suppressed, thereby improving the utilization efficiency of the first light, the second light, and the third light.

[0165] (Note 11) A projector according to any one of Notes 1 to 10, wherein, when observed along the optical axis of the first parallelization element, the first parallelization element covers the first emission end, when observed along the optical axis of the second parallelization element, the second parallelization element covers the second emission end, and when observed along the optical axis of the third parallelization element, the third parallelization element covers the third emission end.

[0166] In the structure of Supplementary Note 11, the amount of the first light, second light, and third light that are not blocked by the first, second, and third parallelizing elements and are taken in can be suppressed, thereby improving the utilization efficiency of the first light, second light, and third light.

[0167] (Note 12) A projector according to any one of Notes 1 to 11, wherein the first light guiding element, the second light guiding element and the third light guiding element are hollow, at least a portion of the first parallelizing element is housed in the first light guiding element, at least a portion of the second parallelizing element is housed in the second light guiding element, and at least a portion of the third parallelizing element is housed in the third light guiding element.

[0168] In the structure of Supplementary Note 12, the amount of the first light, the second light, and the third light that is not blocked by the first, second, and third parallelizing elements and is taken in can be reduced, thereby improving the utilization efficiency of the first light, the second light, and the third light. In addition, in the structure of Supplementary Note 12, the spacing between the first, second, and third light guiding elements and the first, second, and third parallelizing elements in the direction along the optical axis of the first light, the second light, and the third light can be reduced, thereby suppressing the increase in size of the projector.

[0169] (Supplementary Note 13) The projector according to Supplementary Note 3, wherein the first polarizing element is fixed to the first parallelizing element, the second polarizing element is fixed to the second parallelizing element, and the third polarizing element is fixed to the third parallelizing element.

[0170] In the structure of Note 13, the distance between the first parallelization element, the second parallelization element, and the third parallelization element and the first polarization element, the second polarization element, and the third polarization element can be suppressed, the loss of the first light, the second light, and the third light can be suppressed to improve the utilization efficiency of the first light, the second light, and the third light, and the size of the projector can be suppressed.

[0171] (Supplementary Note 14) The projector according to Supplementary Note 5, wherein the cross-sectional shape of the first light guide element is rectangular, the cross-sectional shape of the second light guide element is rectangular, and the cross-sectional shape of the third light guide element is rectangular; when the inclination angle of the side surfaces including the short sides of the first light guide element, the second light guide element, and the third light guide element is α, 7°≤α≤22°; when the inclination angle of the side surfaces including the long sides of the first light guide element, the second light guide element, and the third light guide element is β, 14°≤β≤36°; a reflective film is provided on the inner side surfaces of the first light guide element, the second light guide element, and the third light guide element; and when the reflectivity of the reflective film is the highest, the incident angle of light incident on the reflective film is θ. in When 60°≤θ in ≤90°.

[0172] In the structure of Note 14, the loss of the first light, the second light, and the third light reflected in the first light guide element, the second light guide element, and the third light guide element and emitted from the first emission end, the second emission end, and the third emission end can be suppressed, thereby improving the utilization efficiency of the first light, the second light, and the third light.

[0173] (Note 15) The projector according to Note 3, wherein the projector comprises: a fourth polarization element, which is arranged between the first light modulator and the photosynthetic element, and allows a part of the light emitted from the first light modulator with the fourth polarization component to pass through, and absorbs another part; a fifth polarization element, which is arranged between the second light modulator and the photosynthetic element, and allows a part of the light emitted from the second light modulator with the fifth polarization component to pass through, and absorbs another part; and a sixth polarization element, which is arranged between the third light modulator and the photosynthetic element, and allows a part of the light emitted from the third light modulator with the sixth polarization component to pass through, and absorbs another part.

[0174] In the structure of Note 15, a part of the light emitted from the first light modulator, the second light modulator and the third light modulator having the fourth polarization component, the fifth polarization component and the sixth polarization component can be made incident on the photosynthetic element, and the other part of the light emitted from the first light modulator, the second light modulator and the third light modulator other than the fourth polarization component, the fifth polarization component and the sixth polarization component can be absorbed by the fourth polarization element, the fifth polarization element and the sixth polarization element, thereby suppressing the return light and stray light to the first light modulator, the second light modulator and the third light modulator caused by the other part other than the fourth polarization component, the fifth polarization component and the sixth polarization component.

Claims

1. A projector, characterized in that: have: a first light source emitting first light of a first wavelength band; a second light source emitting second light of a second wavelength band different from the first wavelength band; a third light source emitting third light of a third wavelength band different from the first wavelength band and the second wavelength band; a first light guide element having a first incident end for receiving the first light emitted from the first light source and a first exit end for emitting the first light, and uniformizing the in-plane illuminance of the first light; a second light guide element having a second incident end for receiving the second light emitted from the second light source and a second exit end for emitting the second light, so as to make the in-plane illumination of the second light uniform; a third light guide element having a third incident end for receiving the third light emitted from the third light source and a third exit end for emitting the third light, so as to make the in-plane illumination of the third light uniform; a first parallelizing element for parallelizing the first light emitted from the first light guiding element; a second parallelizing element for parallelizing the second light emitted from the second light guiding element; a third parallelizing element for parallelizing the third light emitted from the third light guiding element; a first light modulation element that modulates the first light emitted from the first parallelization element based on image information; a second light modulation element that modulates the second light emitted from the second parallelizing element based on image information; a third light modulation element that modulates the third light emitted from the third parallelizing element based on image information; a light combining element configured to combine the first light emitted from the first light modulating element, the second light emitted from the second light modulating element, and the third light emitted from the third light modulating element, and emit the combined light; as well as a projection optical system that projects the light emitted from the photosynthetic element, A first focal length of the first parallelizing element is longer than a first length from the first incident end to the first emitting end, a second focal length of the second parallelizing element is longer than a second length from the second incident end to the second emitting end; A third focal length of the third parallelizing element is longer than a third length from the third incident end to the third emitting end.

2. The projector according to claim 1, wherein The cross-section of the first light guide element is rectangular. The cross-section of the second light guide element is rectangular. The cross-section of the third light guide element is rectangular.

3. The projector according to claim 1 or 2, characterized in that The projector has: a first polarizing element disposed between the first parallelizing element and the first light modulating element, transmitting a portion of the first light having the first polarized light component and reflecting another portion; a second polarizing element disposed between the second parallelizing element and the second light modulating element, transmitting a portion of the second light having the second polarized light component and reflecting another portion; as well as a third polarizing element disposed between the third parallelizing element and the third light modulating element, transmitting a portion of the third light having the third polarized light component and reflecting another portion; Another portion of the first light is incident on the first light guide element, Another part of the second light is incident on the second light guide element, Another portion of the third light is incident on the third light guide element.

4. The projector according to claim 1 or 2, characterized in that The cross-sectional area of ​​the first emission end is larger than the cross-sectional area of ​​the first incident end, The cross-sectional area of ​​the second emission end is larger than the cross-sectional area of ​​the second incident end, A cross-sectional area of ​​the third emission end is larger than a cross-sectional area of ​​the third incident end.

5. The projector according to claim 1, wherein A first length from the first incident end to the first emission end is greater than or equal to 8 mm and less than or equal to 25 mm. A second length from the second incident end to the second emission end is greater than or equal to 8 mm and less than or equal to 25 mm. A third length from the third incident end to the third emission end is greater than or equal to 8 mm and less than or equal to 25 mm.

6. The projector according to claim 1 or 2, characterized in that When the first length is g1 and the first focal length is f1, 1.1×g1≤f1≤2.0×g1, When the second length is g2 and the second focal length is f2, 1.1×g2≤f2≤2.0×g2, When the third length is g3 and the third focal length is f3, 1.1×g3≤f3≤2.0×g3.

7. The projector according to claim 1 or 2, characterized in that The focus of the first parallelizing element is located on the side of the first light source opposite to the side from which the first light is emitted. The focus of the second parallelizing element is located on the side of the second light source opposite to the emission side of the second light. A focal point of the third parallelizing element is located on a side of the third light source opposite to an emission side of the third light.

8. The projector according to claim 7, wherein: When the first length is 1, the distance between the position of the focus of the first parallelizing element and the light exit surface of the first light source from which the first light is emitted is greater than or equal to 0.1 and less than or equal to 0.

5.

9. The projector according to claim 1 or 2, characterized in that: The first light guide element, the second light guide element, and the third light guide element are made of glass or metal.

10. The projector according to claim 1 or 2, characterized in that The first light guide element, the second light guide element and the third light guide element are hollow, Reflective films are provided on inner side surfaces of the first light guide element, the second light guide element, and the third light guide element.

11. The projector according to claim 1 or 2, characterized in that When viewed along the optical axis of the first parallelizing element, the first parallelizing element covers the first emission end. When viewed along the optical axis of the second parallelizing element, the second parallelizing element covers the second emission end. When viewed along the optical axis of the third parallelizing element, the third parallelizing element covers the third emission end.

12. The projector according to claim 1 or 2, characterized in that The first light guide element, the second light guide element and the third light guide element are hollow, At least a portion of the first parallelizing element is housed in the first light guiding element. At least a portion of the second parallelizing element is housed in the second light guiding element. At least a portion of the third parallelizing element is housed in the third light guiding element.

13. The projector according to claim 3, wherein The first polarizing element is fixed to the first parallelizing element, The second polarizing element is fixed to the second parallelizing element, The third polarization element is fixed to the third parallelizing element.

14. The projector according to claim 5, wherein The cross-section of the first light guide element is rectangular. The cross-section of the second light guide element is rectangular. The cross-section of the third light guide element is rectangular. When the inclination angle of the side surfaces including the short sides of the first light guide element, the second light guide element, and the third light guide element is α, 7°≤α≤22°, When the inclination angle of the side surfaces including the long sides of the first light guide element, the second light guide element, and the third light guide element is β, 14°≤β≤36°, A reflective film is provided on the inner side surfaces of the first light guide element, the second light guide element, and the third light guide element. When the reflectivity of the reflective film is the highest, the incident angle of the light incident on the reflective film is θ in When 60°≤θ in ≤90°.

15. The projector according to claim 3, wherein The projector has: a fourth polarizing element disposed between the first light modulating element and the light combining element, transmitting a portion of the light emitted from the first light modulating element having a fourth polarized light component and absorbing the remaining portion; a fifth polarizing element disposed between the second light modulator and the light combining element, transmitting a portion of the light emitted from the second light modulator having the fifth polarization component and absorbing the remaining portion; and The sixth polarizing element is disposed between the third light modulator and the light combining element, and transmits a portion of the light having the sixth polarized light component emitted from the third light modulator and absorbs the remaining portion.

Images