Projector

Abstract

To provide a projector capable of projecting a bright image while reducing speckle noise.SOLUTION: A projector comprises: a first light source emitting a first laser beam; a light condensing element; a diffusion member receiving the first laser beam condensed; a collimate element collimating diffusion light emitted from the diffusion member; light intensity distribution changing means for distributing at least part of central light flux of the diffusion light coming from the collimate element toward a peripheral side to change light intensity distribution; a multi-lens array receiving light emitted from the light intensity distribution changing means; an optical modulator modulating light incident from the multi-lens array according to image information; a superposition lens superposing the light on the optical modulator; and a projection optical device projecting the light modulated by the optical modulator. The light intensity distribution changing means is configured such that an incident angle of the diffusion light with the light intensity distribution not yet changed with respect to the light intensity distribution changing means is equal to an emission angle of the diffusion light with the light intensity distribution changed with respect to the light intensity distribution changing means.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] In recent years, laser light sources have been used as the light source for projectors to increase the brightness of image light. In projectors using laser light sources, speckle noise, a speckled pattern caused by the interference of the laser light, is visible on the screen, so measures have been taken to prevent the degradation of display quality caused by speckle noise. For example, in the projector disclosed in Patent Document 1, speckle noise is reduced by making the spatial distribution of light intensity uniform at the exit pupil plane of the projection optical system that projects image light by making laser light incident on a diffusion element that diffuses the light on the optical axis and near the optical axis more than the peripheral areas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-180281 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the projector disclosed in Patent Document 1, the laser light emitted from the rod integrator passes through a diffusion element and is diffused, which causes a disturbance in the imaging relationship between the light emitted from the rod integrator and the light modulation device, making it impossible to efficiently illuminate the light modulation device. [Means for solving the problem]

[0005] In order to solve the above problem, one embodiment of the projector of the present invention comprises a first light source that emits a first laser light, a focusing element that focuses the first laser light, a diffusion member onto which the first laser light focused by the focusing element is incident, a collimating element that collimates the diffused light emitted from the diffusion member, a light intensity distribution changing means that changes the light intensity distribution of the diffused light by distributing at least a portion of the central light beam of the diffused light incident from the collimating element to the periphery, a multi-lens array onto which the light emitted from the light intensity distribution changing means is incident, a light modulation device that modulates the light incident from the multi-lens array in accordance with image information, a superimposing lens that superimposes the light emitted from the multi-lens array on the light modulation device, and a projection optical device that projects the light modulated by the light modulation device, wherein the light intensity distribution changing means has an incident angle of the diffused light with respect to the light intensity distribution changing means before the light intensity distribution is changed that is equal to an exit angle of the diffused light with respect to the light intensity distribution changing means after the light intensity distribution is changed. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a projector 1 according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram illustrating the configuration of a lighting device. [Figure 3] 10A to 10C are diagrams illustrating an example of a method for manufacturing a light intensity distribution changing means. [Figure 4] 3A and 3B are diagrams showing the main configuration and operation of a light intensity distribution changing means; [Figure 5] FIG. 10 is a diagram showing the configuration of a main part of a light intensity distribution changing means according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, the scale of the dimensions of some components may be changed to make each component easier to see.

[0008] [First embodiment] A projector according to a first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing the configuration of a projector 1 according to this embodiment. As shown in FIG. 1, the projector 1 according to this embodiment is a projection-type image display device that displays an image on a screen SCR. The projector 1 includes an illumination device 2, a color separation optical system 3, light modulation devices 4R, 4G, and 4B, a color synthesis optical system 5, and a projection optical device 6. The projector 1 is a three-plate projector having three light modulation devices.

[0009] The illumination device 2 emits illumination light WL3 toward the color separation optical system 3. The illumination light WL3 includes red illumination light RL, green illumination light GL, and blue illumination light BL. The configuration of the illumination device 2 will be described later.

[0010] The color separation optical system 3 separates the illumination light WL3 into red illumination light RL, green illumination light GL, and blue illumination light BL. The color separation optical system 3 includes, for example, a first dichroic mirror 11, a second dichroic mirror 12, a first reflecting mirror 13, a second reflecting mirror 14, a third reflecting mirror 15, a first relay lens 16, and a second relay lens 17.

[0011] The first dichroic mirror 11 is disposed on the optical path of the illumination light WL3 emitted from the illumination device 2 and separates the incident illumination light WL3 into red illumination light RL and green illumination light GL and blue illumination light BL. The first dichroic mirror 11 transmits the red illumination light RL and reflects the green illumination light GL and blue illumination light BL. The second dichroic mirror 12 is disposed on the common optical path of the green illumination light GL and blue illumination light BL emitted from the first dichroic mirror 11 and separates the green illumination light GL from the blue illumination light BL. The second dichroic mirror 12 transmits the blue illumination light BL and reflects the green illumination light GL.

[0012] The first reflecting mirror 13 reflects the red illumination light RL toward the light modulation device 4R. The second reflecting mirror 14 and the third reflecting mirror 15 guide the blue illumination light BL to the light modulation device 4B. The green illumination light GL is reflected from the second dichroic mirror 12 toward the light modulation device 4G.

[0013] The first relay lens 16 is disposed on the optical path of the blue illumination light BL between the second dichroic mirror 12 and the second reflecting mirror 14. The second relay lens 17 is disposed on the optical path of the blue illumination light BL between the second reflecting mirror 14 and the third reflecting mirror 15. By disposing the first relay lens 16 and the second relay lens 17 as described above, optical loss of the blue illumination light BL is compensated for. The optical loss of the blue illumination light BL is caused by the fact that the optical path length of the blue illumination light BL from the first dichroic mirror 11 to the optical modulation device 4B is longer than the optical path length of the red illumination light RL from the first dichroic mirror 11 to the optical modulation device 4R and the optical path length of the green illumination light GL from the first dichroic mirror 11 to the optical modulation device 4G.

[0014] The light modulation device 4R is disposed on the optical path of the red illumination light RL reflected by the first reflecting mirror 13 and emitted from the first reflecting mirror 13. The light modulation device 4R modulates the incident red illumination light RL in accordance with image information input from an image input device (not shown), forms red image light, and emits the red image light. The light modulation device 4G is disposed on the optical path of the green illumination light GL reflected by the second dichroic mirror 12 and emitted from the second dichroic mirror 12. The light modulation device 4G modulates the incident green illumination light GL in accordance with image information input from an image input device (not shown), forms green image light, and emits the green image light. The light modulation device 4B is disposed on the optical path of the blue illumination light BL reflected by the third reflecting mirror 15 and emitted from the third reflecting mirror 15. The light modulation device 4B modulates the incident blue illumination light BL in accordance with image information input from an image input device (not shown), forms blue image light, and emits the blue image light. The image input device may be, for example, a personal computer or a portable terminal device.

[0015] Each of the light modulation devices 4R, 4G, and 4B uses, for example, a transmissive liquid crystal panel. Polarizing plates (not shown) are arranged on the incident and exit sides of the liquid crystal panel. A field lens 10R is arranged on the optical path of the red illumination light RL between the first reflecting mirror 13 and the light modulation device 4R. A field lens 10G is arranged on the optical path of the green illumination light GL between the second dichroic mirror 12 and the light modulation device 4G. A field lens 10B is arranged on the optical path of the blue illumination light BL between the third reflecting mirror 15 and the light modulation device 4B.

[0016] The color combining optical system 5 is disposed across the optical path of the red image light emitted from the light modulation device 4R, the optical path of the green image light emitted from the light modulation device 4G, and the optical path of the blue image light emitted from the light modulation device 4B. When viewed from the top or side as shown in FIG. 1 , the combining position of the colored lights in the color combining optical system 5 overlaps with the intersection of the optical paths of the red image light, the green image light, and the blue image light. In the color combining optical system 5, the red image light, the green image light, and the blue image light are combined together to form colored image light. The color combining optical system 5 emits colored image light. For example, a cross dichroic prism is used for the color combining optical system 5.

[0017] The projection optical device 6 is disposed on the optical path of the color image light emitted from the color combining optical system 5. The color image light emitted from the color combining optical system 5 corresponds to light modulated by the light modulation devices 4R, 4G, and 4B. The projection optical device 6 enlarges and projects the color image light emitted from the color combining optical system 5 and incident thereon onto the screen SCR. The color image light enlarged and projected from the projection optical device 6 is displayed as a color image on the display surface of the screen SCR opposite the emission surface of the projection optical device 6.

[0018] The projection optical device 6 is configured, for example, by a plurality of optical lenses, but may also be configured by a single optical lens. Optical lenses include various lenses such as plano-convex lenses, biconvex lenses, meniscus lenses, aspherical lenses, rod lenses, and free-form lenses.

[0019] Next, a description will be given of the configuration of the lighting device 2. FIG. As shown in FIG. 2, the lighting device 2 includes a first light source 20R, a second light source 20G, a third light source 20B, a light combining member 24, a focusing element 25, a diffusion device 40, a collimating element 26, a light intensity distribution changing means 100, and a superimposing optical system 50 consisting of a multi-lens array 51 and a superimposing lens 52.

[0020] The first light source 20R has a first laser element 21R and a first collimating lens 22R, and emits red light LR. The first laser element 21R emits the red light LR, which is a laser beam. The red light LR has a wavelength band that includes wavelengths belonging to red in the visible wavelength band, for example, a wavelength band of 585 nm to 720 nm. The red light LR is emitted from the first laser element 21R radially around the optical axis AX1. The red light LR corresponds to the first laser beam.

[0021] The first collimating lens 22R is disposed on the optical path of the red light LR emitted from the first laser element 21R and on the optical axis AX1. The center of the first collimating lens 22R in a direction perpendicular to the optical axis AX1 substantially overlaps with the optical axis AX1. The first collimating lens 22R collimates the incident red light LR.

[0022] The second light source 20G has a second laser element 21G and a second collimating lens 22G, and emits green light LG. The second laser element 21G emits the green light LG. The green light LG has a wavelength band that includes wavelengths belonging to green in the visible wavelength band, for example, a wavelength band of 495 nm to 585 nm. The green light LG corresponds to the second light. The green light LG corresponds to the second laser light having a wavelength band different from that of the red light LR.

[0023] The green light LG is emitted from the second laser element 21G radially about an optical axis AX2. When viewed from the top or side as shown in FIG. 2, the optical axis AX2 from the second laser element 21G to the colored light combining position in the light combining member 24 (described later) is perpendicular to the optical axis AX1 from the first laser element 21R to the colored light combining position in the light combining member 24.

[0024] The second collimator lens 22G is disposed on the optical path of the green light LG emitted from the second laser element 21G and on the optical axis AX2. The center of the second collimator lens 22G in a direction perpendicular to the optical axis AX2 substantially overlaps with the optical axis AX2. The second collimator lens 22G collimates the incident green light LG.

[0025] The third light source 20B has a third laser element 21B and a third collimating lens 22B, and emits blue light LB. The third laser element 21B emits the blue light LB. The blue light LB has a wavelength band that includes wavelengths belonging to the blue color within the visible wavelength band, for example, a wavelength band of 380 nm to 495 nm. The blue light LB is emitted radially from the third laser element 21B about an optical axis AX1. The optical axis AX1 of the blue light LB is collinear with the optical axis AX1 of the red light LR, and is an axis that extends from the optical axis AX1 of the red light LR toward the light combining member 24, passing through the position where the colored lights are combined in the light combining member 24, and further extends in the opposite direction from the first light source 20R with respect to the light combining member 24. The blue light LB is emitted parallel to and in the opposite direction to the red light LR with respect to the light combining member 24.

[0026] 2, each of the first light source 20R, the second light source 20G, and the third light source 20B includes one laser light source and one collimating lens, but the number and relative arrangement of the laser light sources and collimating lenses in these light sources are not particularly limited. For example, each of the first light source 20R, the second light source 20G, and the third light source 20B may include two or more laser light sources and the same number of collimating lenses as the number of laser light sources. Each of the first light source 20R, the second light source 20G, and the third light source 20B may include components other than the laser light sources and collimating lenses, such as a package that holds the laser light sources and collimating lenses.

[0027] Light combining member 24 is disposed across the optical path of red light LR emitted from first light source 20R, the optical path of green light LG emitted from second light source 20G, and the optical path of blue light LB emitted from third light source 20B. When viewed from the top or side as shown in Fig. 2, the position where the colored lights are combined in light combining member 24 overlaps with the intersection of the optical paths of red light LR, green light LG, and blue light LB, i.e., the intersection of optical axis AX1 and optical axis AX2.

[0028] In the light combining member 24, the incident red light LR, green light LG, and blue light LB are combined together to generate white light WL. The white light WL corresponds to the combined light. The light combining member 24 emits the white light WL along an optical axis AX2. The optical axis AX2 of the white light WL is collinear with the optical axis AX2 of the green light LG. The optical axis AX2 of the white light WL is an axis that extends from the optical axis AX2 of the green light LG toward the light combining member 24 so as to pass through the position where the colored lights are combined in the light combining member 24, and is further extended in the opposite direction from the second light source 20G relative to the light combining member 24.

[0029] The light combining member 24 includes, for example, a cross dichroic prism 240. The cross dichroic prism 240 includes a first dichroic mirror 241 and a second dichroic mirror 242. In a plan view or a side view in which the optical axes AX1 and AX2 are perpendicular to each other, the reflective surfaces of the first dichroic mirror 241 and the second dichroic mirror 242 are inclined with respect to the optical axes AX1 and AX2. In a plan view or a side view in which the optical axes AX1 and AX2 are perpendicular to each other, the reflective surfaces of the first dichroic mirror 241 and the second dichroic mirror 242 form angles of 45° with the optical axes AX1 and AX2. In a plan view or a side view in which the optical axes AX1 and AX2 are perpendicular to each other, the reflective surfaces of the first dichroic mirror 241 and the second dichroic mirror 242 are perpendicular to each other.

[0030] The first dichroic mirror 241 reflects the blue light LB and transmits the green light LG and red light LR. The second dichroic mirror 242 reflects the red light LR and transmits the blue light LB and green light LG. The red light LR emitted from the first light source 20R is incident on the second dichroic mirror 242 along the optical axis AX1, reflected by the second dichroic mirror 242, and emitted along the optical axis AX2 in the direction opposite to the second light source 20G, where it transmits through the first dichroic mirror 241. The green light LG emitted from the second light source 20G is incident on the first dichroic mirror 241 along the optical axis AX2, travels straight, and transmits through the first dichroic mirror 241 and the second dichroic mirror 242. The blue light LB emitted from the third light source 20B enters the first dichroic mirror 241 along the optical axis AX1, is reflected by the first dichroic mirror 241, and is emitted along the optical axis AX2 to the opposite side from the second light source 20G, and passes through the second dichroic mirror 242.

[0031] As described above, the red illumination light RL, green light LG, and blue light LB emitted from the first dichroic mirror 241 and the second dichroic mirror 242 are combined to generate white light WL. The white light WL is emitted along the optical axis AX2 from the side surface of the cross dichroic prism 240 opposite to the side surface facing the second light source 20G.

[0032] The light-collecting element 25 is disposed on the optical path of the white light WL between the light combining member 24 and the diffuser 40. The light-collecting element 25 collects the white light WL that has been emitted from the light combining member 24 and has been collimated, toward the diffuser 40. The center of the light-collecting element 25 in a direction perpendicular to the optical axis AX2 substantially overlaps with the optical axis AX2. The light-collecting element 25 is, for example, a biconvex lens, but may also be an optical element having a light-collecting function other than a biconvex lens, may be a plano-convex lens, or may be composed of multiple optical lenses.

[0033] The diffusion device 40 is disposed on the optical path of the white light WL emitted from the condensing element 25. The diffusion device 40 diffuses and emits the incident white light WL while being condensed by the condensing element 25. The diffusion device 40 is, for example, a reflective diffusion device, and diffuses and reflects the incident white light WL.

[0034] The diffusion device 40 includes a diffusion member 41 made of a diffusion plate and a drive unit 42. The diffusion member 41 has an incident surface 41a onto which the white light WL collected by the light collecting element 25 is irradiated, and a back surface 41b opposite the incident surface 41a. The diffusion member 41 is disposed with the incident surface 41a facing the light collecting element 25. In a plan view or a side view in which the optical axes AX1 and AX2 are orthogonal to each other, the angle formed between the incident surface 41a and the optical axis AX2 is 45°.

[0035] The diffusion member 41 is attached to the drive device 42 in a state in which it can rotate about a rotation axis OX1. The drive device 42 rotates the diffusion member 41 about the rotation axis OX1. The drive device 42 is, for example, a motor. Note that the drive device 42 is not limited to a motor and may be any device that can rotate the diffusion member 41 as described above.

[0036] In the diffusion device 40, a focused spot SP of the white light WL is formed on the incident surface 41a of the diffusion member 41. The incident surface 41a has a scattering surface having an uneven structure that scatters the white light WL. The white light WL diffused by the diffusion member 41 is emitted from the focused spot SP as diffused light and enters the collimator element 26. Hereinafter, the white light WL emitted from the diffusion device 40 will be referred to as diffused light WL1.

[0037] In the projector 1 of this embodiment, the color lights LR, LG, and LB contained in the white light WL are coherent lights, which may cause optical interference. In the illumination device 2 of this embodiment, the white light WL is diffused by the diffusion member 41 of the diffusion device 40, thereby making the light distribution of the light projected onto the screen SCR uniform and reducing speckle noise. Furthermore, by rotating the diffusion member 41, the spatial distribution of the speckle noise, which changes from moment to moment, is superimposed over time, further reducing the speckle noise.

[0038] However, it is difficult to sufficiently reduce speckle noise by diffusing light alone. The inventors have noticed that speckle noise can be reduced by adjusting the light intensity distribution of the exit pupil image of the projection lens of the projector. Specifically, the inventors have completed the projector 1 of this embodiment, which is capable of reducing speckle noise by adjusting the light intensity distribution of the exit pupil image so that the light intensity in the periphery is higher than the light intensity in the center. Hereinafter, the white light WL emitted from the diffusion device 40 will be referred to as diffused light WL1.

[0039] The projector 1 of this embodiment includes a light intensity distribution changing means 100 that changes the light intensity distribution of the diffused light WL1 by distributing at least a part of the central luminous flux of the diffused light WL1 to the periphery.

[0040] In the projector 1 of this embodiment, the diffused light WL1 is collimated by the collimating element 26 and made incident on the light intensity distribution changing means 100. The chief ray of the diffused light WL1 coincides with the optical axis AX10 of the collimating element 26. The collimating element 26 is, for example, a biconvex lens, but it may also be an optical element other than a biconvex lens that has a light-collecting function, a plano-convex lens, or may be composed of multiple optical lenses. Note that when the collimating element 26 is composed of a single optical lens, the accuracy of collimation can be further improved by using an aspherical lens.

[0041] The configuration of the light intensity distribution changing means 100 will be described below. The light intensity distribution changing means 100 includes a light beam moving section 110, a reflecting section 120, and a plurality of prisms . The light beam moving section 110 is disposed symmetrically with respect to an optical axis 100C passing through the center of the light intensity distribution changing means 100. The optical axis 100C of the light intensity distribution changing means 100 coincides with the optical axis AX10 of the collimating element .

[0042] The light beam moving unit 110 moves at least a portion of the incident light beam in a direction away from the optical axis 100C. The light beam moving unit 110 has a plurality of optical elements 111. The plurality of optical elements 111 are arranged side by side in a direction perpendicular to the optical axis 100C. In the present embodiment, two optical elements 111 are arranged so as to be line-symmetric with respect to the optical axis 100C. In other words, the light beam moving unit 110 has four optical elements 111. Note that the number of optical elements 111 constituting the light beam moving unit 110 is not limited to the above and can be changed as appropriate depending on the structure of the light intensity distribution changing means 100.

[0043] Each optical element 111 is configured as a partial transmission mirror that transmits part of the incident light and reflects the other part of the incident light. In this embodiment, each optical element 111 is configured as a so-called half mirror that transmits half of the incident light and reflects the other half. In addition, the ratio of the transmittance and reflectance of incident light in a partially transmitting mirror is not limited to 50:50, and can be, for example, either a state in which the transmittance is higher than the reflectance or a state in which the transmittance is lower than the reflectance, and can be changed as appropriate depending on the optical characteristics required of the optical element 111.

[0044] The reflecting unit 120 is disposed on the opposite side of the light beam moving unit 110 from the optical axis 100C, and reflects the light separated by the light beam moving unit 110 in a direction along the optical axis 100C. The reflecting unit 120 has a pair of mirrors 121. Each mirror 121 is disposed in a direction perpendicular to the optical axis 100C. Each mirror 121 is made of a thin film such as a metal film or a dielectric multilayer film. In this embodiment, the pair of mirrors 121 are arranged to sandwich both ends of the light beam moving section 110 in a direction perpendicular to the optical axis 100C.

[0045] The plurality of prisms 130 hold the plurality of optical elements 111 and the plurality of mirrors 121. The plurality of prisms 130 includes one first prism 131 and a plurality of second prisms 132. The first prism 131 and the plurality of second prisms 132 are arranged side by side in a direction perpendicular to the optical axis 100C. The first prism 131 is a triangular prism having a triangular cross-sectional shape. In this embodiment, the first prism 131 is formed by bonding two light-transmitting substrates together as described below, but may also be formed from a single light-transmitting member. Each second prism 132 is composed of a quadrangular prism having a parallelogram cross section. The first prism 131 is arranged on the optical axis 100C, and two second prisms 132 are arranged on either side of the first prism 131 in a direction perpendicular to the optical axis 100C. The first prisms 131 and the second prisms 132 are arranged so that their side surfaces are butted against each other to form a trapezoidal cross section as a whole. The number of the plurality of prisms 130 is not limited to the above, and can be changed as appropriate depending on the structure of the light intensity distribution changing means 100, for example, the number of optical elements 111.

[0046] Each optical element 111 is disposed so as to be sandwiched between a first prism 131 and a second prism 132, or between two second prisms 132. Each mirror 121 is disposed in a pair of second prisms 132 that are farthest from the optical axis 100C in a direction perpendicular to the optical axis 100C, among the multiple second prisms 132. Each optical element 111 and each mirror 121 are disposed so as to form an angle of 45 degrees with respect to the optical axis 100C.

[0047] The light intensity distribution changing means 100 of this embodiment is configured by a prism array in which a plurality of optical elements 111 and a plurality of mirrors 121 are held by a plurality of prisms 130. Therefore, it is possible to realize a structure in which the plurality of optical elements 111 and the plurality of mirrors 121 are precisely arranged at predetermined positions with respect to the optical axis 100C.

[0048] Here, we will explain a method for manufacturing the light intensity distribution changing means 100. Figure 3 is a diagram showing an example of a method for manufacturing the light intensity distribution changing means 100. As shown in Figure 3, two optical components 116 are formed by cutting a laminate 115 consisting of three light-transmitting substrates, one light-transmitting substrate 113 having optical films 112 formed on both sides thereof, which constitute an optical element 111, between two light-transmitting substrates 114, in an oblique direction at an angle of 45 degrees to the stacking direction. Next, a mirror 121 is formed on one outermost surface 116a of one optical component 116, and the other outermost surface 116b of the optical component 116 is processed into a right-angled surface. The other optical component 116 is also processed in the same manner. Then, by joining the right-angled surfaces 116c, 116c of the two optical components 116 together, the light intensity distribution changing means 100 of this embodiment can be manufactured.

[0049] Here, we will explain the behavior of light incident on the light intensity distribution changing means 100. Figure 4 is a diagram showing the main configuration of the light intensity distribution changing means 100 and its action. 4, the diffused light WL1 is collimated by the collimating element 26 and enters the light intensity distribution changing means 100 as a parallel beam. The diffused light WL1 passes through a plurality of prisms 130 and enters a plurality of optical elements 111, respectively.

[0050] Hereinafter, in Figure 4, one of the multiple optical elements 111 held by the first prism 131 will be referred to as the first optical element 111a, the optical element 111 arranged on the opposite side of the optical axis 100C from the first optical element 111a (the right side in Figure 4) will be referred to as the second optical element 111b, and one mirror 121 arranged on the opposite side of the optical axis 100C from the second optical element 111b (the right side in Figure 3) will be referred to as the mirror 121a.

[0051] A first component WL11, which is a part of the diffused light WL1 incident on the first optical element 111a, passes through the first optical element 111a and the prism 130, is emitted from the light intensity distribution changing means 100, and travels along the optical axis 100C. On the other hand, the second component WL12, which is another part of the diffused light WL1 incident on the first optical element 111a, is reflected by the first optical element 111a in a direction perpendicular to the optical axis 100C and away from the optical axis 100C, passes through the prism 130, and is incident on the adjacent second optical element 111b.

[0052] The third component WL13, which is part of the second component WL12 incident from the first optical element 111a, passes through the second optical element 111b, travels in a direction perpendicular to the optical axis 100C and away from the optical axis 100C, and is incident on the mirror 121a. On the other hand, the fourth component WL14, which is another part of the second component WL12 incident from the first optical element 111a, is reflected by the second optical element 111b in a direction along the optical axis 100C, passes through the prism 130, and is emitted from the light intensity distribution changing means 100, traveling along the optical axis 100C.

[0053] Furthermore, a fifth component WL15, which is a part of the diffused light WL1 that is incident on the second optical element 111b, is transmitted through the second optical element 111b and the prism 130. At this time, the fifth component WL15 is combined with the fourth component WL14 that is reflected by the second optical element 111b, and is emitted from the light intensity distribution changing means 100, and travels along the optical axis 100C. On the other hand, the sixth component WL16, which is another part of the diffused light WL1 incident on the second optical element 111b, is reflected by the second optical element 111b in a direction perpendicular to the optical axis 100C and away from the optical axis 100C, passes through the prism 130, and is incident on the mirror 121a.

[0054] The mirror 121a reflects the third component WL13 and the sixth component WL16 incident from the second optical element 111b in a direction along the optical axis 100C. The third component WL13 and the sixth component WL16 reflected by the mirror 121a are transmitted through the prism 130, and then emitted from the light intensity distribution changing means 100, and travel along the optical axis 100C.

[0055] The light intensity distribution changing means 100 emits the first component WL11 from a portion corresponding to the first optical element 111a, emits the fourth component WL14 and the fifth component WL15 from a portion corresponding to the second optical element 111b, and emits the third component WL13 and the sixth component WL16 from a portion corresponding to the mirror 121a. The light intensity distribution changing means 100 emits the first component WL11, the second component WL12, the third component WL13, the fourth component WL14, the fifth component WL15, and the sixth component WL16 as parallel light along the optical axis 100C.

[0056] In this way, the light intensity distribution changing means 100 can distribute a part of the light incident on the first optical element 111a to the second optical element 111b and the mirror 121a. In the light intensity distribution changing means 100, the first optical element 111a is a portion close to the optical axis 100C, and corresponds to the region on which the central luminous flux of the diffused light WL1 is incident.

[0057] In the above explanation, the behavior of light on one side (the right side in FIG. 4) of the optical axis 100C has been explained, but the same can be said about the behavior of light on the other side (the left side in FIG. 4) of the optical axis 100C.

[0058] In this embodiment, the diffused light WL1 is diffused light emitted from the light-condensing spot SP of the diffusing member 41, and therefore has a light intensity distribution in which the light intensity at the center is higher than that at the periphery. The light intensity distribution changing means 100 of this embodiment can change the light intensity distribution of the diffused light WL1 by distributing a portion of the central light beam of the diffused light WL1 incident from the collimating element 26 to the peripheral side, thereby making the light intensity of the central part of the diffused light WL1 relatively low while making the light intensity of the peripheral part relatively high.

[0059] Furthermore, the light intensity distribution changing means 100 of this embodiment can emit diffused light WL1, which has entered as parallel light, as parallel light. That is, the light intensity distribution changing means 100 has an incident angle of the diffused light WL1, before the light intensity distribution is changed, that is, an exit angle of the diffused light WL1, after the light intensity distribution is changed, that is, the incident angle of the diffused light WL1, before the light intensity distribution is changed, that is, In this way, the light intensity distribution changing means 100 of this embodiment can change the light intensity distribution without changing the parallel state of the diffused light WL1 before and after incidence.

[0060] In the light intensity distribution changing means 100 of this embodiment, each optical element 111 is configured as a partially transmitting mirror, and therefore it is possible to extract light that has passed through each optical element 111. This makes it possible to prevent problems such as a decrease in the number of ray bundles contained in the diffused light WL1 emitted from the light intensity distribution changing means 100, resulting in increased in-plane illuminance unevenness.

[0061] Furthermore, according to the light intensity distribution changing means 100 of this embodiment, by arranging multiple optical elements 111 in a direction perpendicular to the optical axis 100C, it is possible to finely adjust the light intensity distribution of the diffused light WL1 in a direction perpendicular to the optical axis 100C. This makes it possible to reduce in-plane illuminance unevenness of the diffused light WL1. Furthermore, the light intensity distribution changing means 100 can minimize optical loss of the diffused light WL1 before and after incidence by reflecting the light beams moved to both ends of the light beam moving section 110 with a pair of mirrors 121 and extracting them in a direction along the optical axis 100C.

[0062] In this specification, the diffused light WL1 whose light intensity distribution has been changed by the light intensity distribution changing means 100 is referred to as illumination light WL3. The illumination light WL3 emitted from the light intensity distribution changing means 100 is incident on the superimposing optical system 50. The superimposing optical system 50 has a multi-lens array 51 and a superimposing lens 52. The superimposing optical system 50 homogenizes the illuminance distribution of the illumination light WL3 in the image forming areas of the light modulation devices 4R, 4G, and 4B arranged downstream.

[0063] The multi-lens array 51 is disposed on the optical path of the illumination light WL3. The multi-lens array 51 is, for example, a double-sided multi-lens array. The double-sided multi-lens includes a plurality of microlenses 53 for dividing the illumination light WL3 into a plurality of small beams. The microlenses 53 are arranged adjacent to one another in a matrix along a plane perpendicular to the optical axis AX10. The microlenses 53 are, for example, plano-convex lenses that are convex toward the incident side. The double-sided multi-lens has a first multi-lens surface 51a provided on the incident side in accordance with the shape of the plano-convex lenses that form the microlenses 53. The double-sided multi-lens includes a plurality of microlenses 54, the same number as the plurality of microlenses 53, on a plane perpendicular to the optical axis AX10. The microlenses 54 are arranged adjacent to one another in a matrix along a plane perpendicular to the optical axis AX10, and overlap with each other. The microlenses 54 are, for example, plano-convex lenses that are convex toward the exit side. The exit-side plane of each of the plurality of microlenses 54 is common to the entrance-side plane of each of the plurality of microlenses 53. The double-sided multi-lens has a second multi-lens surface 51b provided on the exit side along the shape of the plano-convex lens that forms the microlens 54.

[0064] The superimposing lens 52 collects each of the multiple small beams of the illumination light WL3 emitted from the multi-lens array 51, and superimposes the collected beams on each other in the image forming area of ​​each of the light modulation devices 4R, 4G, and 4B or in the vicinity of the image forming area in cooperation with the multiple microlenses 54 of the multi-lens array 51. The superimposing lens 52 is, for example, a plano-convex lens, but it may also be an optical element having a light collecting function other than a plano-convex lens, or it may be a biconvex lens, or it may be composed of multiple optical lenses.

[0065] In the projector 1 of this embodiment, the color lights LR, LG, and LB contained in the white light WL are coherent lights, which may cause optical interference. The illumination device 2 of this embodiment diffuses the white light WL using the diffusion member 41 of the diffusion device 40 to uniform the light distribution of the light projected onto the screen SCR, and further reduces speckle noise by rotating the diffusion member 41 to superimpose the spatial distribution of speckle noise, which changes from moment to moment, over time.

[0066] However, it is difficult to sufficiently reduce speckle noise using only the diffusion member 41. Therefore, the present inventor focused on the fact that speckle noise can be further reduced by adjusting the light intensity distribution of the exit pupil image of the projection lens of the projector. Specifically, the present inventor completed the projector 1 of this embodiment, which has a configuration that can further reduce speckle noise by adjusting the light intensity distribution of the exit pupil image of the projection lens so that the light intensity in the peripheral part is higher than the light intensity in the central part.

[0067] Specific effects of the projector 1 of this embodiment will be described below. In the projector 1 of this embodiment, there is an optically conjugate relationship between the second multi-lens surface 51b, which is the light exit surface of the multi-lens array 51, and the exit pupil of the projection optical device 6. In the projector 1 of this embodiment, the light intensity distribution on the second multi-lens surface 51b of the multi-lens array 51, which is conjugate with the exit pupil of the projection optical device 6, is adjusted so that the light intensity in the periphery is higher than the light intensity in the center.

[0068] Specifically, the projector 1 of this embodiment uses the light intensity distribution changing means 100 to distribute at least a portion of the central light flux of the diffused light WL1 to the periphery, thereby generating illumination light WL3 having a light intensity distribution in which the light intensity is higher in the periphery than in the center, and can cause the illumination light WL3 to be incident on the multi-lens array 51. As a result, the illumination light WL3 forms an image on the light exit surface (second multi-lens surface 51b) of the multi-lens array 51, having a light intensity distribution in which the light intensity is higher in the periphery than in the center. In other words, the illumination light WL3 can form an image on the exit pupil of the projection optical device 6, which is optically conjugate with the light exit surface of the multi-lens array 51, having a light intensity distribution in which the light intensity is higher in the periphery than in the center.

[0069] Therefore, according to the projector 1 of this embodiment, an exit pupil image having a light intensity distribution in which the light intensity in the peripheral part is higher than the light intensity in the central part is formed on the exit pupil of the projection optical device 6, thereby more effectively reducing speckle noise.

[0070] Furthermore, in the projector 1 of this embodiment, the light intensity distribution changing means 100 is configured so that the angle of incidence of the diffused light WL1 before the change in light intensity distribution to the light intensity distribution changing means 100 is equal to the angle of emergence of WL1 after the change in light intensity distribution to the light intensity distribution changing means 100. Therefore, the light intensity distribution changing means 100 can generate illumination light WL3 with a changed light intensity distribution of the diffused light WL1 without changing the parallel state of the diffused light WL1 before and after incidence.

[0071] Here, as a comparative example, a case will be described where the collimated state of the illumination light WL3 changes after passing through the light intensity distribution changing means 100. When the collimated state of the illumination light WL3 changes before and after it enters the light intensity distribution changing means 100, the imaging state of the color illumination lights RL, GL, and BL that illuminate the image forming areas of the light modulation devices 4R, 4G, and 4B by the superimposing optical system 50 changes, and the color illumination lights RL, GL, and BL cannot efficiently illuminate the image forming areas, resulting in a deterioration in the quality of the image projected on the screen SCR.

[0072] In contrast, according to the projector 1 of this embodiment, the parallel state of the illumination light WL3 that passes through the light intensity distribution changing means 100 does not change, so the imaging state of each color illumination light RL, GL, BL that illuminates each image forming area of ​​the light modulation devices 4R, 4G, 4B by the superimposition optical system 50 does not change, and by efficiently illuminating each image forming area, it is possible to project a bright, blur-free, high-quality image onto the screen SCR.

[0073] [Second embodiment] Next, a second embodiment of the projector of the present invention will be described. The projector of this embodiment and the projector of the first embodiment have the same configuration except for the configuration of the light intensity distribution changing means. Therefore, the following mainly describes the configuration of the light intensity distribution changing means, and common members and configurations are assigned the same reference numerals and detailed descriptions are omitted.

[0074] FIG. 5 is a diagram showing the configuration of the main part of the light intensity distribution changing means 200 of this embodiment. 5, the light intensity distribution changing means 200 has a light flux moving section 210 having a plurality of optical elements 211, a reflecting section 120, and a plurality of prisms 130. The optical axis passing through the center of the light intensity distribution changing means 200 is referred to as an optical axis 200C.

[0075] In this embodiment, each optical element 211 is configured as a mirror that reflects incident light. Like each mirror 121 that configures the reflecting section 120, each optical element 211 is configured from a metal film, a dielectric multilayer film, or the like. In other words, unlike the optical element 111 configured as a half mirror in the first embodiment, each optical element 211 reflects incident light without transmitting it.

[0076] In this embodiment, the plurality of optical elements 211 are arranged such that two optical elements 211 adjacent to each other in a direction perpendicular to the optical axis 200C do not overlap each other in a direction along the optical axis 200C.

[0077] In Figure 5, one of the multiple optical elements 211 held by the first prism 131 is referred to as the first optical element 211a, the optical element 211 arranged on the opposite side of the optical axis 200C (right side in Figure 5) from the first optical element 211a is referred to as the second optical element 211b, and one mirror 121 arranged on the opposite side of the optical axis 200C from the second optical element 211b (right side in Figure 5) is referred to as the mirror 121a.

[0078] Specifically, the end 211a1 on the light exit side of the first optical element 211a is arranged with a gap in the left-right direction of Figure 5, which is perpendicular to the optical axis 200C, relative to the end 211b1 on the light entrance side of the second optical element 211b, so that they do not overlap in the direction along the optical axis 200C.

[0079] In the light intensity distribution changing means 200 of this embodiment, each optical element 211 is a mirror that does not have optical transparency. Therefore, according to the light intensity distribution changing means 200 of this embodiment, mirrors are arranged on the optical axis 200C and in the vicinity of the optical axis 200C, so most of the light flux in the peripheral portion of the optical axis 200C can be distributed to the peripheral side. Therefore, the light intensity distribution changing means 200 of this embodiment can further reduce the light intensity of the central portion of the illumination light WL3 compared to the light intensity distribution changing means 100 of the first embodiment.

[0080] Here, we will explain the case where there is no gap between adjacent optical elements 211 in the left-right direction in Fig. 5. In this case, the number of ray bundles contained in the illumination light WL3 emitted from the light intensity distribution changing means 200 decreases. This increases the in-plane illuminance unevenness of the illumination light WL3, making it difficult to uniformly illuminate the image formation areas of the light modulation devices 4R, 4G, and 4B even when the superimposing optical system 50 is used.

[0081] In contrast, in the light intensity distribution changing means 200 of this embodiment, a portion of the diffused light WL1 is emitted as a transmitted component WL17 that has passed through the gaps between adjacent optical elements 211, thereby suppressing a decrease in the ray flux contained in the illumination light WL3. This makes it possible to suppress problems caused by increased in-plane illuminance unevenness of the illumination light WL3. The second optical element 211b and the mirror 121a may be arranged with a gap between them in the left-right direction of FIG.

[0082] Therefore, even in a projector using the light intensity distribution changing means 200 of this embodiment, an exit pupil image is formed on the exit pupil of the projection optical device 6, which has a light intensity distribution in which the light intensity in the periphery is higher than the light intensity in the center, thereby more effectively reducing speckle noise.

[0083] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. In the above-described embodiments, the light intensity distribution changing means 100, 200 are each configured as a prism array including a plurality of prisms 130. However, the configuration of the light intensity distribution changing means of the present invention is not limited to this. For example, the light intensity distribution changing means may be configured as a light beam moving unit and a reflecting unit. In this case, the plurality of optical elements that make up the light beam moving unit and the plurality of mirrors that make up the reflecting unit may be arranged in predetermined positions by, for example, a housing (not shown) that holds other optical components of the lighting device, instead of prisms.

[0084] When a prism array is used as in the above embodiment, the thickness of each optical element constituting the light beam moving section and each mirror constituting the reflecting section can be reduced. In contrast, when the optical elements and mirrors are not held by prisms, the optical elements and mirrors must be made of metal plates to maintain a certain level of rigidity. Because the end faces of the optical elements and mirrors made of metal plates have a certain thickness, there is a risk of light loss occurring due to scattering or reflection of the incident light. Therefore, when prioritizing the reduction of light loss in the light intensity distribution changing means, it is desirable to also use a prism array as in the above embodiment.

[0085] Furthermore, although the lighting device 2 of the above embodiment is equipped with a rotating diffuser 40, the diffuser 40 does not necessarily have to be able to rotate the diffusing member 41, and may be of a fixed type. Furthermore, although the diffuser 40 is a reflective diffuser that diffuses and reflects the incident white light WL, a transmissive diffuser that diffuses and transmits the incident white light WL may also be used.

[0086] In the projector of the above embodiment, coherent white light WL is emitted from the illumination device 2, diffused by the diffusion device 40, and the diffused light WL1 is incident on the light intensity distribution changing means 100, 200. However, the present invention is not limited to this. For example, the present invention may be applied to a monochromatic projector equipped with an illumination device that emits monochromatic illumination light and one light modulation device. When applying the present invention to a monochromatic projector, it is preferable to apply the present invention to a projector that diffuses red illumination light, which is prone to noticeable speckle noise, and causes the red diffused light to enter the light intensity distribution changing means, and modulates the red diffused light transmitted through the light intensity distribution changing means to display a red image. This reduces speckle noise in red light, which is highly visible to humans. Therefore, the speckle noise reduction effect can be efficiently achieved.

[0087] In addition, the specific descriptions of the shape, number, arrangement, materials, etc. of each component of the lighting device and projector are not limited to the above embodiments and can be modified as appropriate. The present invention may be applied to a projector that uses a digital micromirror device as a light modulation device. Furthermore, the projector of the present invention does not need to have multiple light modulation devices, and may be a single-panel projector that has only one light modulation device.

[0088] Summary of this disclosure A summary of this disclosure is provided below.

[0089] (Appendix 1) a first light source that emits a first laser beam; a focusing element that focuses the first laser beam; a diffusing member onto which the first laser light condensed by the condensing element is incident; a collimating element that collimates the diffused light emitted from the diffusing member; a light intensity distribution changing means for changing the light intensity distribution of the diffused light by distributing at least a part of the central luminous flux of the diffused light incident from the collimating element to a peripheral side; a multi-lens array onto which the light emitted from the light intensity distribution changing means is incident; a light modulation device that modulates the light incident from the multi-lens array in accordance with image information; a superimposing lens that superimposes the light emitted from the multi-lens array onto the light modulation device; a projection optical device that projects the light modulated by the light modulation device; Equipped with the light intensity distribution changing means is configured so that an incident angle of the diffused light with respect to the light intensity distribution changing means before the light intensity distribution is changed is equal to an exit angle of the diffused light with respect to the light intensity distribution changing means after the light intensity distribution is changed; projector.

[0090] With this configuration of the projector, the light intensity distribution changing means can redirect at least a portion of the central luminous flux of the diffused light to the periphery, causing light having a light intensity distribution in which the light intensity is higher in the periphery than in the center to be incident on the multi-lens array, thereby forming an image on the exit pupil of the projection optical device having a light intensity distribution in which the light intensity is higher in the periphery than in the center. Therefore, with a projector of this configuration, an exit pupil image is formed on the exit pupil of the projection optical device, which has a light intensity distribution in which the light intensity in the periphery is higher than the light intensity in the center, thereby more effectively reducing speckle noise in the first laser light. Furthermore, in a projector of this configuration, the parallel state of the light that passes through the light intensity distribution changing means does not change, so the imaging state of the light modulation device using the superimposing lens does not change, and by efficiently illuminating the light modulation device, it is possible to project a bright, high-quality image without blur onto the projection surface.

[0091] (Appendix 2) The light intensity distribution changing means a light beam moving unit that is arranged symmetrically with respect to the optical axis and moves at least a part of the light beam of the incident light in a direction away from the optical axis; a reflecting section disposed on the opposite side of the light beam moving section from the optical axis, the reflecting section reflecting the light incident from the light beam moving section in a direction along the optical axis; having 1. The projector according to claim 1.

[0092] With this configuration, the central luminous flux of the diffused light that has been distributed to the peripheral portion by the luminous flux moving portion can be emitted in a direction along the optical axis by the reflecting portion, and the light intensity distribution changing means can cause light having a luminous intensity distribution in which the luminous intensity is higher in the peripheral portion than in the central portion to be incident on the multi-lens array.

[0093] (Appendix 3) the light beam moving unit has a plurality of optical elements arranged in a direction perpendicular to the optical axis, the reflecting section has a pair of mirrors sandwiching both ends of the light beam moving section in a direction perpendicular to the optical axis, 2. The projector according to claim 1,

[0094] With this configuration, the light intensity distribution of the diffused light can be finely adjusted in a direction perpendicular to the optical axis. In addition, by reflecting the light beams moved to both ends of the light beam moving unit by a pair of mirrors and extracting them in a direction along the optical axis, it is possible to minimize the light loss that occurs before and after entering the light intensity distribution changing means.

[0095] (Appendix 4) Each of the plurality of optical elements is a partially transmitting mirror that transmits a part of incident light and reflects another part of the incident light. 2. The projector according to claim 1, wherein the projector is a

[0096] With this configuration, since each optical element is configured as a partially transmitting mirror, it is possible to extract the light that has passed through each optical element, thereby suppressing the occurrence of problems such as an increase in in-plane illuminance unevenness due to a decrease in the number of ray bundles contained in the light emitted from the light intensity distribution changing means.

[0097] (Appendix 5) the light intensity distribution changing means further includes a plurality of prisms that hold the plurality of optical elements and the pair of mirrors. 1. The projector according to claim 3 or 4.

[0098] According to this configuration, the light intensity distribution changing means can be configured by a prism array in which a plurality of optical elements and a pair of mirrors are held by a plurality of prisms, thereby realizing a structure in which a plurality of optical elements and a plurality of mirrors are precisely arranged in predetermined positions. Furthermore, the thickness of each optical element constituting the light beam transfer section and each mirror constituting the reflecting section can be reduced, thereby suppressing the occurrence of light loss due to scattering or reflection of light by the end faces of each optical element and each mirror.

[0099] (Appendix 6) Each of the plurality of optical elements is composed of a mirror, At least one of two optical elements adjacent to each other in a direction perpendicular to the optical axis is arranged so as not to overlap with each other in a direction along the optical axis. 6. The projector according to claim 3, wherein the projector is a

[0100] With this configuration, a portion of the diffused light passes through the gaps between adjacent optical elements and is emitted, thereby suppressing a decrease in the ray flux contained in the light that has passed through the light intensity distribution changing means, thereby suppressing problems caused by increased in-plane illuminance unevenness of the light that has passed through the light intensity distribution changing means.

[0101] (Appendix 7) a light exit surface of the multi-lens array and an exit pupil of the projection optical device are optically conjugate. 7. The projector according to claim 1.

[0102] According to this configuration, it is possible to realize a configuration in which the light intensity distribution on the exit pupil of the projection optical device is adjusted by controlling the light intensity distribution on the light exit surface of the multi-lens array using the light intensity distribution changing means.

[0103] (Appendix 8) the first laser light is red light; 8. The projector according to claim 1, wherein the projector is a

[0104] This configuration can reduce speckle noise of red light, which is highly visible to humans, and therefore can efficiently achieve the effect of reducing speckle noise.

[0105] (Appendix 9) a second light source that emits a second laser beam having a wavelength band different from that of the first laser beam; a light combining member that emits a combined light obtained by combining the first laser light and the second laser light, the combined light emitted from the light combining member is collected by the light collecting element and is incident on the diffusing member, The diffused light of the combined light emitted from the diffusing member passes through the collimating element and enters the light intensity distribution changing means. 9. The projector according to any one of claims 1 to 8.

[0106] This configuration makes it possible to reduce speckle noise in the combined light made up of the first laser light and the second laser light, thereby providing a projector that reduces speckle noise in light of two different colors. [Explanation of symbols]

[0107] 1...projector, 4B, 4G, 4R...light modulation device, 6...projection optical device, 20G...second light source, 20R...first light source, 24...light combining element, 25...light focusing element, 26...collimating element, 41...diffusing element, 51...multi-lens array, 52...superimposing lens, 100, 200...light intensity distribution changing means, 100C, 200C...optical axis, 110, 210...light beam moving section, 111, 211...optical element, 120...reflecting section, 121...mirror, 130...prism, LR...red light (first laser light), LG...green light (second laser light), WL1...diffused light, WL...white light (combined light).

Claims

1. a first light source that emits a first laser beam; a focusing element that focuses the first laser beam; a diffusing member onto which the first laser light condensed by the condensing element is incident; a collimating element that collimates the diffused light emitted from the diffusing member; a light intensity distribution changing means for changing the light intensity distribution of the diffused light by distributing at least a part of the central luminous flux of the diffused light incident from the collimating element to a peripheral side; a multi-lens array onto which the light emitted from the light intensity distribution changing means is incident; a light modulation device that modulates the light incident from the multi-lens array in accordance with image information; a superimposing lens that superimposes the light emitted from the multi-lens array onto the light modulation device; a projection optical device that projects the light modulated by the light modulation device; Equipped with the light intensity distribution changing means is configured so that an incident angle of the diffused light with respect to the light intensity distribution changing means before the light intensity distribution is changed is equal to an exit angle of the diffused light with respect to the light intensity distribution changing means after the light intensity distribution is changed; projector.

2. The light intensity distribution changing means a light beam moving unit that is arranged symmetrically with respect to the optical axis and moves at least a part of the light beam of the incident light in a direction away from the optical axis; a reflecting section disposed on the opposite side of the light beam moving section from the optical axis, the reflecting section reflecting the light incident from the light beam moving section in a direction along the optical axis; having The projector according to claim 1 .

3. the light beam moving unit has a plurality of optical elements arranged in a direction perpendicular to the optical axis, the reflecting section has a pair of mirrors sandwiching both ends of the light beam moving section in a direction perpendicular to the optical axis, The projector according to claim 2 .

4. Each of the plurality of optical elements is a partially transmitting mirror that transmits a part of incident light and reflects another part of the incident light. The projector according to claim 3 .

5. the light intensity distribution changing means further includes a plurality of prisms that hold the plurality of optical elements and the pair of mirrors.

5. The projector according to claim 3 or 4.

6. Each of the plurality of optical elements is composed of a mirror, At least one of two optical elements adjacent to each other in a direction perpendicular to the optical axis is arranged so as not to overlap with each other in a direction along the optical axis.

5. The projector according to claim 3 or 4.

7. a light exit surface of the multi-lens array and an exit pupil of the projection optical device are optically conjugate. The projector according to claim 1 .

8. the first laser light is red light; The projector according to claim 1 .

9. a second light source that emits a second laser beam having a wavelength band different from that of the first laser beam; a light combining member that combines the first laser light and the second laser light and emits a combined light, the combined light emitted from the light combining member is collected by the light collecting element and is incident on the diffusing member, The diffused light of the combined light emitted from the diffusing member passes through the collimating element and enters the light intensity distribution changing means. The projector according to claim 1 .

Images