Projection display device

Abstract

The present invention comprises: a solid-state light source that emits light having a specific wavelength; a phosphor (3) that is excited by irradiation with said light and emits light having a wavelength different from that of said light; a condensing optical system that is disposed between the solid-state light source and the phosphor (3) and condenses the light on the phosphor (3); a dichroic mirror (4) which is disposed between the solid-state light source and the condensing optical system, reflects the light toward the condensing optical system, and transmits irradiation light with which the phosphor (3) was irradiated; and a first lens array (6A) and a second lens array (6B) which are disposed on the opposite side of the light condensing optical system so as to sandwich the dichroic mirror (4), and in which a plurality of lens cells (110) are arrayed. The dichroic mirror (4) is disposed such that at least one end surface (4a) is positioned between the lens cells (110), (110) of the first lens array (6A).

Description

Projection type display device

[0001] The present disclosure relates to a projection display device.

[0002] In general, a projection display device is known that includes a light source device that emits light from a source, an illumination optical system that illuminates a plurality of light modulation elements with different color lights separated from the light source light, a synthesizing optical system that synthesizes the plurality of color lights optically modulated by the light modulation elements to generate synthesized light, and a projection optical system that projects the synthesized light generated by the synthesizing optical system (see, for example, Patent Document 1). In this type of projection display device, the light source device includes a solid-state light source that emits light of a specific wavelength, a phosphor that is excited by irradiation with light and irradiates light of a different wavelength from the light, a condensing lens that is arranged between the solid-state light source and the phosphor and condenses the light onto the phosphor, and a dichroic mirror that is arranged between the solid-state light source and the condensing lens and reflects light toward the condensing lens and transmits the irradiation light irradiated by the phosphor, and the illuminance of the irradiation light that has passed through the dichroic mirror is made uniform by a fly's eye lens in which a plurality of lens cells are arranged.

[0003] JP 2008-158274 A

[0004] However, as the dichroic mirror becomes smaller as the light source device becomes smaller, the end face of this dichroic mirror overlaps with the lens cell of the fly's eye lens, which can result in degradation of the projected image quality and uneven brightness, leaving room for improvement.

[0005] An object of an aspect of the present disclosure is to provide a projection display device that can suppress deterioration of projected image quality and uneven brightness.

[0006] The projection display device of this embodiment includes a solid-state light source that emits light of a specific wavelength, a phosphor that is excited by irradiation with light and emits light of a different wavelength from the light, a focusing lens that is arranged between the solid-state light source and the phosphor and focuses the light onto the phosphor, a dichroic mirror that is arranged between the solid-state light source and the focusing lens and reflects light toward the focusing lens and transmits the light irradiated by the phosphor, and a fly's eye lens that is arranged on the opposite side of the focusing lens across the dichroic mirror and has a plurality of lens cells arranged therein, and the dichroic mirror is arranged so that at least one outer edge is located between the lens cells of the fly's eye lens.

[0007] According to this embodiment, it is possible to suppress deterioration of the projected image quality and uneven brightness.

[0008] Fig. 1 is a plan view schematically showing an example of a projection display device according to the present embodiment. Fig. 2 is a perspective view schematically showing an example of a projection display device according to the present embodiment. Fig. 3 is a schematic diagram showing a suitable positional relationship between a dichroic mirror, a first lens array, and a second lens array in the projection display device according to the present embodiment. Fig. 4 is a schematic diagram showing an inappropriate positional relationship between a dichroic mirror, a first lens array, and a second lens array in the projection display device according to the present embodiment.

[0009] Although embodiments of the present disclosure will be described with reference to the drawings, the present disclosure is not limited thereto. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0010] In the following description, an XYZ Cartesian coordinate system is set, and the positional relationships of each part are described with reference to this XYZ Cartesian coordinate system. The direction parallel to the X axis, which is the first axis within a predetermined plane, is defined as the X axis direction. The direction parallel to the Y axis, which is the second axis orthogonal to the first axis within the predetermined plane, is defined as the Y axis direction. The direction parallel to the Z axis, which is the third axis orthogonal to the first and second axes, is defined as the Z axis direction. The third axis is orthogonal to the predetermined plane. Furthermore, one direction in the X axis direction is defined as the +X direction, and the opposite direction of the +X direction (also referred to as the reverse direction) is defined as the -X direction. One direction in the Y axis direction is defined as the +Y direction, and the opposite direction of the +Y direction is defined as the -Y direction. One direction in the Z axis direction is defined as the +Z direction, and the opposite direction of the +Z direction is defined as the -Z direction. In this embodiment, the predetermined plane is parallel to the horizontal plane, and the Z axis direction is the vertical direction. In the following description, the predetermined plane will be referred to as the XY plane as appropriate.

[0011] FIG. 1 is a plan view schematically illustrating an example of a projection display device 100 according to this embodiment. FIG. 2 is a perspective view schematically illustrating an example of the projection display device 100 according to this embodiment. As shown in FIGS. 1 and 2, the projection display device 100 includes a light source device 1 that emits light (light source light), a cross separation element 9 having two separation elements arranged crossing each other, and an illumination optical system 10 that separates the light emitted from the light source device 1 into a first color light (blue light) Lb, a second color light (red light) Lr, and a third color light (green light) Lg by color separation, and an illumination optical system 10 that is arranged on the optical paths of the first color light Lb, the second color light Lr, and the third color light Lg generated by the illumination optical system 10 and that outputs the first color light Lb, the second color light Lr, and the third color light Lg based on image data. The optical system includes a first reflective liquid crystal panel 31, a second reflective liquid crystal panel 32, and a third reflective liquid crystal panel 33 that optically modulate the first color light Lb, the second color light Lr, and the third color light Lg, respectively; a combining optical system 40 that combines the first color light Lb, the second color light Lr, and the third color light Lg that have been optically modulated by the first reflective liquid crystal panel 31, the second reflective liquid crystal panel 32, and the third reflective liquid crystal panel 33 to generate combined light; and a projection optical system 50 that projects the combined light generated by the combining optical system 40.

[0012] The light source device 1 generates white light, which is light source light. In this embodiment, the light source device 1 includes a solid-state light source 2 that emits excitation light, a phosphor 3 that generates fluorescence when irradiated with the excitation light, a dichroic mirror 4 that guides the excitation light emitted from the solid-state light source 2 to the phosphor 3, and a focusing optical system (condensing lens) 5 that focuses the excitation light irradiated on the phosphor 3. The solid-state light source 2 includes a laser diode (LD). The solid-state light source 2 emits blue laser light of a specific wavelength as excitation light. The excitation light emitted from the solid-state light source 2 is irradiated onto the phosphor 3 via the dichroic mirror 4 and the focusing optical system 5. When irradiated with the excitation light, the phosphor 3 generates yellow fluorescence with a wavelength different from that of the excitation light (blue laser light). White light is generated based on the excitation light and the fluorescence. The white light generated by the light source device 1 enters an illumination optical system 10.

[0013] The illumination optical system 10 separates the light emitted from the light source device 1 into a plurality of color lights Lb, Lr, and Lg. The illumination optical system 10 causes the first color light Lb to be incident on a first reflective liquid crystal panel 31, the second color light Lr to be incident on a second reflective liquid crystal panel 32, and the third color light Lg to be incident on a third reflective liquid crystal panel 33. The illumination optical system 10 comprises an integrator optical system 6 into which light from the light source device 1 is incident, a cross separation element 9 that separates the light emitted from the integrator optical system 6 into first color light Lb, second color light Lr, and third color light Lg, a first reflecting member 13 that reflects the first color light Lb separated by the cross separation element 9 in the +Z direction, a second reflecting member 14 that reflects the second color light Lr separated by the cross separation element 9 in the +Z direction, a third reflecting member 15 that reflects the third color light Lg separated by the cross separation element 9 in the +Z direction, and a relay optical system 20 that is arranged in the optical path of the first color light Lb and forms an erect image.

[0014] The integrator optical system 6 uniforms the illuminance of the light emitted from the light source device 1. The integrator optical system 6 includes a first lens array (fly-eye lens) 6A, a second lens array (fly-eye lens) 6B, a polarization conversion element 7, and a condenser lens (first optical component) 8. The optical axis of the integrator optical system 6 is parallel to the Y axis. The light emitted from the integrator optical system 6 travels in the +Y direction.

[0015] The first lens array 6A has a plurality of microlenses arranged in a matrix in the XZ plane. The second lens array 6B has a plurality of microlenses arranged in a matrix in the XZ plane. The plurality of microlenses of the first lens array 6A and the plurality of microlenses of the second lens array 6B correspond one-to-one. The polarization conversion element 7 has a plurality of polarization conversion units. The polarization conversion units include a polarization separation film, a reflecting mirror, and a phase plate. The plurality of microlenses of the second lens array 6B and the plurality of polarization conversion units of the polarization conversion element 7 correspond one-to-one.

[0016] Light emitted from the light source device 1 and entering the integrator optical system 6 is incident on each of the multiple microlenses of the first lens array 6A. Depending on the position of the microlens, a portion of the light incident on the entrance surface of the integrator optical system 6 is incident on each of the multiple microlenses of the first lens array 6A. Therefore, the light received by each microlens is different. Each microlens of the first lens array 6A focuses the light emitted from the light source device 1 onto each microlens of the second lens array 6B corresponding to each microlens of the first lens array 6A. A secondary light source image is formed on each of the multiple microlenses of the second lens array 6B. The second lens array 6B constitutes the optical pupil of the first lens array 6A.

[0017] Light from the secondary light source images formed on each microlens of the second lens array 6B is incident on each polarization conversion unit of the polarization conversion element 7 corresponding to the microlens of the second lens array 6B. The light incident on the polarization conversion unit is separated by a polarization separation film into light of a first polarization state and light of a second polarization state. The light of the second polarization state separated by the polarization separation film is reflected by a reflecting mirror and then passes through a phase plate, where it is converted into light of the first polarization state. In other words, the light emitted from the light source device 1 is converted into light of the first polarization state by passing through the polarization conversion element 7.

[0018] The light emitted from each of the multiple polarization conversion units is incident on the condenser lens 8. The condenser lens 8 superimposes the light emitted from each of the multiple polarization conversion units into a single light beam. This homogenizes the illuminance distribution on each of the first reflective liquid crystal panel 31, the second reflective liquid crystal panel 32, and the third reflective liquid crystal panel 33. The condenser lens 8 also functions as a first optical component that adjusts the direction of bias in the light intensity distribution of the second color light Lr, which is red light, and the third color light Lg, which is green light, separated by the cross separation element 9, by adjusting the light emitted from the light source device 1. The integrator optical system 6 may include a rod integrator.

[0019] The cross separation element 9 has a first color separation element 11 and a second color separation element 12, which are integrally formed and cross each other in an X-shape when viewed from the Z direction. The cross separation element 9 is disposed on the -Y side of the integrator optical system 6. The first color separation element 11 and the second color separation element 12 each include a dichroic mirror. The first color separation element 11 reflects the first color light Lb from the light emitted from the light source device 1 and transmitted through the integrator optical system 6, thereby separating the first color light Lb. The second color separation element 12 reflects the second color light Lr from the light transmitted through the integrator optical system 6, thereby separating the second color light Lr. In this embodiment, the first color separation element 11 reflects the first color light Lb and transmits the second color light Lr and the third color light Lg. The second color separation element 12 reflects the second color light Lr and transmits the first color light Lb and the third color light Lg. Therefore, the cross separation element 9 separates the white light from the light source device 1 using the first color separation element 11 into blue light, which is the first color light Lb, and light of a different wavelength from the blue light, and the second color separation element 12 separates the white light from the light source device 1 into red light, which is the second color light Lr, and light of a different wavelength from the red light, using the second color separation element 12. The first color light Lb, which is blue light, is reflected by the first color separation element 11 and travels in the −X direction. The second color light Lr, which is red light, is reflected by the second color separation element 12 and travels in the +X direction. The remaining third color light Lg, which is green light, is transmitted through the first color separation element 11 and the second color separation element 12 and travels in the −Y direction.

[0020] The first reflecting member 13 reflects the first color light Lb from the first color separation element 11 in the +Z direction. In this embodiment, the illumination optical system 10 has a fourth reflecting member 16 and a fifth reflecting member 17 disposed between the first color separation element 11 and the first reflecting member 13. The fourth reflecting member 16 is disposed on the −X side of the first color separation element 11, and the fifth reflecting member 17 is disposed on the −Y side of the fourth reflecting member 16. The fourth reflecting member 16 reflects the first color light Lb from the first color separation element 11 in the −Y direction, and the fifth reflecting member 17 reflects the first color light Lb from the fourth reflecting member 16 in the +X direction. The first color light Lb traveling in the −X direction from the first color separation element 11 is reflected by the reflecting surface 16A of the fourth reflecting member 16 and travels in the −Y direction, and then reflected by the reflecting surface 17A of the fifth reflecting member 17 and travels in the +X direction. The first reflecting member 13 is disposed on the +X side of the fifth reflecting member 17. The first colored light Lb traveling in the +X direction from the fifth reflecting member 17 is reflected by the reflecting surface 13A of the first reflecting member 13 and travels in the +Z direction.

[0021] The second reflecting member 14 reflects the second color light Lr from the second color separation element 12 in the +Z direction. The second reflecting member 14 is disposed on the +X side of the second color separation element 12. The second color light Lr traveling in the +X direction from the second color separation element 12 is reflected by the reflecting surface 14A of the second reflecting member 14 and travels in the +Z direction.

[0022] The third reflecting member 15 reflects in the +Z direction the third color light Lg that has passed through the first color separation element 11 and the second color separation element 12. The third reflecting member 15 is disposed on the -Y side of the first color separation element 11 and the second color separation element 12. The third color light Lg that travels in the +Y direction from the first color separation element 11 and the second color separation element 12 is reflected by the reflecting surface 15A of the third reflecting member 15 and travels in the +Z direction.

[0023] In this embodiment, the reflecting surface 13A of the first reflecting member 13 and the reflecting surface 14A of the second reflecting member 14 are parallel to each other. The reflecting surface 13A of the first reflecting member 13 is parallel to the Y axis and is inclined in the +Z direction toward the −X direction. Similarly, the reflecting surface 15A of the third reflecting member 15 is parallel to the X axis and is inclined in the +Z direction toward the +Y direction.

[0024] In this embodiment, the reflecting surface 13A of the first reflecting member 13 and the reflecting surface 14A of the second reflecting member 14 are arranged in the same plane. The plane including the reflecting surface 13A of the first reflecting member 13 and the reflecting surface 14A of the second reflecting member 14 is perpendicular to the plane including the reflecting surface 15A of the third reflecting member 15.

[0025] The relay optical system 20 is disposed in the optical path of the first color light Lb between the first color separation element 11 and the first reflective liquid crystal panel 31. In this embodiment, the relay optical system 20 is disposed in the optical path of the first color light Lb between the first color separation element 11 and the first reflecting member 13. The relay optical system 20 forms an erect image of an object on the object plane side of the relay optical system 20 on the image plane side of the relay optical system 20.

[0026] The relay optical system 20 includes a first condensing lens 21 disposed between the fourth reflecting member 16 and the fifth reflecting member 17, and a second condensing lens 22 and a third condensing lens 23 disposed between the fifth reflecting member 17 and the first reflecting member 13. The first condensing lens 21, the second condensing lens 22, and the third condensing lens 23 are each a convex lens. The third condensing lens 23 is optically conjugate with the second lens array 6B. Because the third condensing lens 23 and the second lens array 6B are optically conjugate and the second lens array 6B acts as a pupil of the first lens array 6A, an image of each microlens of the first lens array 6A is formed between the second lens array 6B and the third condensing lens 23. In this embodiment, a lens (e.g., the third condensing lens 23) included in the relay optical system 20 functions as a second optical component that adjusts the direction of bias in the light intensity distribution of the first color light Lb, which is blue light, separated by the cross separation element 9.

[0027] In this embodiment, the relay optical system 20 forms an erect image of an object on the image plane side of the relay optical system 20. For example, when an image X is formed on the object plane side of the relay optical system 20, the relay optical system 20 forms an inverted image of the image X between the first color separation element 11 and the first reflective liquid crystal panel 31, which is the image plane, and forms an erect image of the image X on the image plane side of the relay optical system 20. In this embodiment, the image X refers to each of the images of a portion of the light emitted from the light source device 1 and received by each of the multiple microlenses of the first lens array 6A.

[0028] The first reflective liquid crystal panel 31 is disposed in the optical path of the first color light Lb. The first reflective liquid crystal panel 31 is an optical modulation element that optically modulates the first color light Lb from the first reflecting member 13 based on image data. The first reflective liquid crystal panel 31 is disposed on the +Z side of the first reflecting member 13. The first color light Lb traveling in the +Z direction from the first reflecting member 13 is incident on the first reflective liquid crystal panel 31.

[0029] The first reflective liquid crystal panel 31 has a first incident surface 31A onto which the first color light Lb from the first reflecting member 13 is incident. The first reflective liquid crystal panel 31 reflects the first color light Lb from the first reflecting member 13 in the −Z direction.

[0030] The second reflective liquid crystal panel 32 is disposed in the optical path of the second color light Lr. The second reflective liquid crystal panel 32 is a light modulation element that optically modulates the second color light Lr from the second reflecting member 14 based on image data. The second reflective liquid crystal panel 32 is disposed on the +Z side of the second reflecting member 14. The second color light Lr traveling in the +Z direction from the second reflecting member 14 is incident on the second reflective liquid crystal panel 32.

[0031] The second reflective liquid crystal panel 32 has a second incident surface 32A onto which the second color light Lr is incident from the second reflecting member 14. The second reflective liquid crystal panel 32 reflects the second color light Lr from the second reflecting member 14 in the −Z direction.

[0032] The third reflective liquid crystal panel 33 is disposed in the optical path of the third color light Lg. The third reflective liquid crystal panel 33 is an optical modulation element that optically modulates the third color light Lg from the third reflecting member 15 based on image data. The third reflective liquid crystal panel 33 is disposed on the +Z side of the third reflecting member 15. The third color light Lg traveling in the +Z direction from the third reflecting member 15 is incident on the third reflective liquid crystal panel 33.

[0033] The third reflective liquid crystal panel 33 has a third incident surface 33A onto which the third color light Lg is incident from the third reflecting member 15. The third reflective liquid crystal panel 33 reflects the third color light Lg from the third reflecting member 15 in the −Z direction.

[0034] The first incident surface 31A of the first reflective liquid crystal panel 31 is parallel to the XY plane and faces in the -Z direction. Similarly, the second incident surface 32A of the second reflective liquid crystal panel 32 and the third incident surface 33A of the third reflective liquid crystal panel 33 are parallel to the XY plane and face in the -Z direction. In this embodiment, the first incident surface 31A of the first reflective liquid crystal panel 31, the second incident surface 32A of the second reflective liquid crystal panel 32, and the third incident surface 33A of the third reflective liquid crystal panel 33 are arranged in the same plane that is parallel to the XY plane.

[0035] A condenser lens 25, a first polarizer 61, and a second polarizer 62 are arranged in the optical path of the first color light Lb between the first reflecting member 13 and the first reflective liquid crystal panel 31. A condenser lens 26, a third polarizer 63, and a fourth polarizer 64 are arranged in the optical path of the second color light Lr between the second reflecting member 14 and the second reflective liquid crystal panel 32. A condenser lens 27, a fifth polarizer 65, and a sixth polarizer 66 are arranged in the optical path of the third color light Lg between the third reflecting member 15 and the third reflective liquid crystal panel 33.

[0036] The first polarizer 61 transmits the first color light Lb in the first polarization state reflected by the first reflecting member 13. The first color light Lb in the first polarization state transmitted through the first polarizer 61 is incident on the first reflective liquid crystal panel 31 via the second polarizer 62. The first reflective liquid crystal panel 31 optically modulates the first color light Lb from the first polarizer 61 based on image data. The second polarizer 62 is disposed in the optical path of the first color light Lb between the first polarizer 61 and the first reflective liquid crystal panel 31. The second polarizer 62 transmits the first color light Lb in the first polarization state from the first polarizer 61 and reflects the first color light Lb in the second polarization state from the first reflective liquid crystal panel 31 to the combining optical system 40.

[0037] The third polarizer 63 transmits the second color light Lr in the first polarization state reflected by the second reflecting member 14. The second color light Lr in the first polarization state transmitted through the third polarizer 63 is incident on the second reflective liquid crystal panel 32 via the fourth polarizer 64. The second reflective liquid crystal panel 32 optically modulates the second color light Lr from the third polarizer 63 based on image data. The fourth polarizer 64 is disposed in the optical path of the second color light Lr between the third polarizer 63 and the second reflective liquid crystal panel 32. The fourth polarizer 64 transmits the second color light Lr in the first polarization state from the third polarizer 63 and reflects the second color light Lr in the second polarization state from the second reflective liquid crystal panel 32 to the combining optical system 40.

[0038] The fifth polarizer 65 transmits the third color light Lg in the first polarization state reflected by the third reflecting member 15. The third color light Lg in the first polarization state transmitted through the fifth polarizer 65 is incident on the third reflective liquid crystal panel 33 via the sixth polarizer 66. The third reflective liquid crystal panel 33 optically modulates the third color light Lg from the fifth polarizer 65 based on image data. The sixth polarizer 66 is disposed in the optical path of the third color light Lg between the fifth polarizer 65 and the third reflective liquid crystal panel 33. The sixth polarizer 66 transmits the third color light Lg in the first polarization state from the fifth polarizer 65 and reflects the third color light Lg in the second polarization state from the third reflective liquid crystal panel 33 to the combining optical system 40.

[0039] A transmissive polarizer 67 is disposed in the optical path of the first color light Lb between the second polarizer 62 and the combining optical system 40. The transmissive polarizer 67 transmits the first color light Lb in the second polarization state out of the first color light Lb emitted from the second polarizer 62 to the combining optical system 40, and prevents the transmission of unnecessary first color light Lb in the first polarization state.

[0040] A transmission polarizer 68 is disposed in the optical path of the second color light Lr between the fourth polarizer 64 and the combining optical system 40. The transmission polarizer 68 transmits the second color light Lr in the second polarization state out of the second color light Lr emitted from the fourth polarizer 64 to the combining optical system 40, and prevents the transmission of the unnecessary second color light Lr in the first polarization state.

[0041] A transmission polarizer 69 is disposed in the optical path of the third color light Lg between the sixth polarizer 66 and the combining optical system 40. The transmission polarizer 69 transmits the third color light Lg in the second polarization state out of the third color light Lg emitted from the sixth polarizer 66 to the combining optical system 40, and prevents the transmission of the unnecessary third color light Lg in the first polarization state. The first polarization state is, for example, a P polarization state. The second polarization state is, for example, an S polarization state.

[0042] In this embodiment, the projection display device 100 has the same optical path length from the cross separation element 9 to the second reflective liquid crystal panel 32 corresponding to red light and the same optical path length from the cross separation element 9 to the third reflective liquid crystal panel 33 corresponding to green light, and equivalent optical components are arranged on the optical paths of the red light and the green light. Therefore, the red light and green light separated by the cross separation element 9 can be appropriately sent to the second reflective liquid crystal panel 32 and the third reflective liquid crystal panel 33, where they can form images, respectively. On the other hand, the optical path length from the cross separation element 9 to the first reflective liquid crystal panel 31 corresponding to blue light is set longer than the optical path lengths of the red light and green light. By providing a relay optical system 20 in the optical path of the blue light, the blue light can be imaged once in the optical path and then re-imaged on the first reflective liquid crystal panel 31 via the relay optical system 20.

[0043] In this embodiment, the first, second, and third incident surfaces 31A, 32A, and 33A of the first, second, and third reflective liquid crystal panels 31, 32, and 33 are optically conjugate with the respective microlenses of the first lens array 6A. Therefore, the images of the respective microlenses of the first lens array 6A are superimposed on the first, second, and third incident surfaces 31A, 32A, and 33A of the first, second, and third reflective liquid crystal panels 31, 32, and 33. This makes the illuminance distribution at the first, second, and third incident surfaces 31A, 32A, and 33A of the first, second, and third reflective liquid crystal panels 31, 32, and 33 uniform.

[0044] The combining optical system 40 generates combined light by combining the first color light Lb optically modulated by the first reflective liquid crystal panel 31, the second color light Lr optically modulated by the second reflective liquid crystal panel 32, and the third color light Lg optically modulated by the third reflective liquid crystal panel 33. In this embodiment, the combining optical system 40 includes a cross dichroic prism. The combining optical system 40 has an incident surface 41 onto which the first color light Lb optically modulated by the first reflective liquid crystal panel 31 is incident, an incident surface 42 onto which the second color light Lr optically modulated by the second reflective liquid crystal panel 32 is incident, an incident surface 43 onto which the third color light Lg optically modulated by the third reflective liquid crystal panel 33 is incident, and an exit surface 46 from which the combined light emerges.

[0045] The incident surface 41 is parallel to the XZ plane and faces in the -Y direction. The incident surface 42 is parallel to the XZ plane and faces in the +Y direction. The incident surface 43 is parallel to the YZ plane and faces in the -X direction. The exit surface 46 is parallel to the YZ plane and faces in the +X direction.

[0046] The combining optical system 40 has a first combining surface 44 that combines the first color light Lb incident from the incident surface 41 and the third color light Lg incident from the incident surface 43, and a second combining surface 45 that combines the third color light Lg incident from the incident surface 43 and the second color light Lr incident from the incident surface 42. The first combining surface 44 and the second combining surface 45 are parallel to the Z axis. The first combining surface 44 and the second combining surface 45 are orthogonal to each other.

[0047] The first synthesis surface 44 reflects the first color light Lb that has exited the first reflective liquid crystal panel 31 and entered the incident surface 41 via the second polarizer 62. The first synthesis surface 44 transmits the third color light Lg that has exited the third reflective liquid crystal panel 33 and entered the incident surface 43 via the sixth polarizer 66.

[0048] The second combining surface 45 transmits the third color light Lg that has exited the third reflective liquid crystal panel 33 and entered the incident surface 43 via the sixth polarizer 66. The second combining surface 45 reflects the second color light Lr that has exited the second reflective liquid crystal panel 32 and entered the incident surface 42 via the fourth polarizer 64.

[0049] The projection optical system 50 projects the combined light generated by the combining optical system 40 and emitted from the emission surface 46 onto the screen 70. The projection optical system 50 is optically conjugate with the second lens array 6B. The surface of the screen 70 is also optically conjugate with each of the multiple microlenses of the first lens array 6A.

[0050] Next, the positional relationship between the dichroic mirror 4 and the first and second lens arrays 6A and 6B in the projection display device 100 according to this embodiment will be described. Fig. 3 is a schematic diagram showing a suitable positional relationship between the dichroic mirror 4 and the first and second lens arrays 6A and 6B in the projection display device 100 according to this embodiment. Fig. 4 is a schematic diagram showing an inappropriate positional relationship between the dichroic mirror 4 and the first and second lens arrays 6A and 6B in the projection display device 100 according to this embodiment.

[0051] As described above, the dichroic mirror 4 reflects the excitation light emitted from the solid-state light source 2 ( FIG. 1 ) toward the phosphor 3, and transmits the yellow fluorescence generated by the phosphor 3 in response to irradiation with the excitation light, guiding the fluorescence to the first lens array 6A and the second lens array 6B. The dichroic mirror 4 has a configuration in which a dichroic coating is applied to the surface 4c of a glass plate, for example, and is formed with an outer diameter smaller than that of the first lens array 6A in order to reduce the size of the light source device 1. In this embodiment, as shown in FIG. 3 , the dichroic mirror 4 is disposed obliquely with respect to the first lens array 6A, so that the projection width when projected onto the first lens array 6A is smaller than the width of the first lens array 6A.

[0052] In this way, if the projection width of the dichroic mirror 4 projected onto the first lens array 6A is smaller than the width of the first lens array 6A, the end faces (outer edges) 4a, 4b of the dichroic mirror 4 will overlap with the lens cells 110 of the first lens array 6A, which may result in problems such as deterioration in the image quality of the combined light projected onto the screen 70 and uneven brightness, and there is room for improvement in this regard.

[0053] For this reason, in this embodiment, the dichroic mirror 4 is positioned so that at least one end face 4 a is located between the vertices 110A, 110A of adjacent lens cells 110, 110 of the first lens array 6A. Specifically, the dichroic mirror 4 is positioned so that the point 4 a 1 where the thickness d of the glass plate at one end face 4 a is halfway overlaps with the recess 111 between adjacent lens cells 110, 110 of the first lens array 6A. With this configuration, as indicated by arrows 151 in the brightness distribution 150 of FIG. 3 , the area of ​​reduced brightness is located between the lens cells, thereby suppressing problems such as degradation of the image quality of the combined light projected onto the screen 70 and uneven brightness. This brightness distribution 150 is used to confirm the effect of the end faces 4 a, 4 b of the dichroic mirror 4 using an optical simulator, and uses the wavelength of light irradiated by the phosphor 3. In this case, because there is a lot of yellow fluorescence around the periphery of the dichroic mirror 4, the optical characteristics are adjusted to that of yellow fluorescence, but the reflection and scattering of light at the end faces 4a and 4b of the dichroic mirror 4 can be simulated with high accuracy by calculating the wavelengths of green light to red light. In Figure 3, the other end face 4b is also arranged so as to overlap with the recess 111 between adjacent lens cells 110 of the first lens array 6A.

[0054] Here, it is preferable that of the end faces 4a, 4b of the dichroic mirror 4, the end face farther from the first lens array 6A (end face 4a in FIG. 3) be positioned so that it overlaps with the recessed portion 111 between the lens cells 110, 110. In this case, the side farther from the first lens array 6A is more affected by light reflected or scattered by the end face 4a, so it is more effective to position the dichroic mirror 4 so that the end face 4a of the dichroic mirror 4 farther from the first lens array 6A overlaps with the recessed portion 111 between the lens cells 110, 110.

[0055] On the other hand, as shown in Figure 4, when the end faces (4a, 4b) of the dichroic mirror overlap the vertices 110A of the lens cells 110 of the first lens array 6A, the flatness of the light distribution at both ends is degraded compared to Figure 3. However, when one end face 4a of the dichroic mirror 4 (the side farther from the first lens array 6A) is positioned so as to overlap the vertices 110A of the lens cells 110 of the first lens array 6A, the portion of the brightness distribution 150A where the reduced brightness overlaps the lens cells 110 is shown by arrow 151. Therefore, problems such as degradation in the image quality of the combined light projected onto the screen 70 and uneven brightness are greater than in the case of the other end face 4b of the dichroic mirror 4 (the side closer to the first lens array 6A). In other words, it can be seen that the impact of the end face 4a, which is farther from the first lens array 6A, is greater. Therefore, it is desirable to align both end faces 4a and 4b of the dichroic mirror 4 with the recesses 111 between the lens cells 110 of the first lens array 6A, but it is better to give priority to improving the end face 4a that is farther away from the first lens array 6A.

[0056] As described above, the projection display device 100 according to this embodiment comprises a solid-state light source 2 that emits light of a specific wavelength, a phosphor 3 that is excited by irradiation with light and emits light of a different wavelength from the light emitted by the solid-state light source 2, a focusing optical system 5 that is arranged between the solid-state light source 2 and the phosphor 3 and focuses the light onto the phosphor 3, a dichroic mirror 4 that is arranged between the solid-state light source 2 and the focusing optical system 5 and reflects light toward the focusing optical system 5 and transmits the light irradiated by the phosphor 3, and a first lens array 6A and a second lens array 6B that are arranged on the opposite side of the dichroic mirror 4 from the focusing optical system 5 and have a plurality of lens cells 110 arranged therein, and the dichroic mirror 4 is arranged so that at least one end face 4a is located between the lens cells 110 of the first lens array 6A.

[0057] With this configuration, the portion of the light that has reduced brightness due to reflection or scattering at the end face 4a of the dichroic mirror 4 overlaps the recess 111 between the lens cells 110, 110, thereby suppressing problems such as deterioration in the image quality of the combined light projected onto the screen 70 and uneven brightness.

[0058] In the projection display device 100 of this embodiment, the dichroic mirror 4 is positioned at an angle relative to the first lens array 6A, and the end face 4a of the dichroic mirror 4 on the side farther from the first lens array 6A is located between the lens cells 110, 110.Therefore, by suppressing the effects of light reflected or scattered at the end face 4a on the side farther from the first lens array 6A, problems such as deterioration in the image quality of the combined light projected onto the screen 70 and uneven brightness can be further suppressed.

[0059] In the projection display device 100 of this embodiment, the dichroic mirror 4 has a glass plate, and one end face 4a of this glass plate is located between the lens cells 110, 110. Therefore, by suppressing the effects of light reflected or scattered by this end face 4a, it is possible to further suppress problems such as deterioration in the image quality of the combined light projected onto the screen 70 and uneven brightness.

[0060] In the projection display device 100 of this embodiment, the projection width of the dichroic mirror 4 when projected onto the first lens array 6A is smaller than the width of the first lens array 6A, so that the light source device 1 equipped with this dichroic mirror 4 can be made smaller.

[0061] In the projection display device 100 of this embodiment, the wavelength of the light irradiated from the phosphor 3 is used to confirm the effect of the end face 4a of the dichroic mirror 4 using an optical simulator, so that the effect that the positional relationship between the end face 4a of the dichroic mirror 4 and the lens cell 110 has on the image quality and brightness of the combined light projected onto the screen 70 can be accurately determined.

[0062] Although the configuration of the projection type display device 100 according to this embodiment has been described above, the configuration of the projection type display device 100 is not limited to the above embodiment.

[0063] The projection display device of this embodiment can be used in light projection technology that generates composite light by combining a plurality of color lights modulated by a light modulation element and projects this composite light, for example.

[0064] REFERENCE SIGNS LIST 1 Light source device 2 Solid-state light source 3 Phosphor 4 Dichroic mirror 4a End surface (outer edge) 5 Condensing optical system 6A First lens array (fly's eye lens) 6B Second lens array (fly's eye lens) 9 Cross separation element 10 Illumination optical system 11 First color separation element 12 Second color separation element 20 Relay optical system 21 First condensing lens 22 Second condensing lens 23 Third condensing lens 31 First reflective liquid crystal panel 32 Second reflective liquid crystal panel 33 Third reflective liquid crystal panel 40 Combining optical system 50 Projection optical system 70 Screen 100 Projection display device 110 Lens cell 111 Recess

Claims

1. A projection display device comprising: a solid-state light source that emits light of a specific wavelength; a phosphor that is excited by irradiation with said light and emits light of a different wavelength from the light; a focusing lens that is arranged between said solid-state light source and said phosphor and focuses said light onto said phosphor; a dichroic mirror that is arranged between said solid-state light source and said focusing lens and reflects said light toward said focusing lens and transmits the light irradiated by said phosphor; and a fly's eye lens that is arranged on the opposite side of said focusing lens with said dichroic mirror in between and has a plurality of lens cells arranged therein, wherein at least one outer edge of said dichroic mirror is positioned between the lens cells of said fly's eye lens.

2. A projection display device according to claim 1, wherein the dichroic mirror is disposed at an angle to the fly's eye lens, and the outer edge of the dichroic mirror on the side farther from the fly's eye lens is positioned between the lens cells.

3. A projection display device according to claim 1 or 2, wherein the dichroic mirror has a glass plate, one end surface of which is positioned between the lens cells.

4. The projection display device according to claim 1 or 2, wherein the dichroic mirror has a projection width when projected onto the fly-eye lens that is smaller than the width of the fly-eye lens.

5. The projection display device according to claim 1 or 2, wherein the influence of the end face of the dichroic mirror is confirmed by an optical simulator using the wavelength of the light emitted from the phosphor.

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