JP2017040746A - projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector being capable of being reduced in size while suppressing a reduction in luminous efficiency.SOLUTION: A projector comprises: a light source section 10 emitting first light K; a first lens array 12a to which the first light K is incident; a second lens array 12b to which the first light K transmitted through the first lens array 12a is incident; a light separation element 14 separating the first light K transmitted through the second lens array 12b into a first bundle of rays BLp and a second bundle of rays BLs; a first superposition lens 15 to which the first bundle of rays BLp is incident; a wavelength conversion element 34 to which the first bundle of rays BLp emitted from the first superposition lens 15 is incident; a second superposition lens 17 to which the second bundle of rays BLs is incident; image formation sections 4R, 4G and 4B modulating second light YL emitted from the wavelength conversion element 34 and the second bundle of rays BLs emitted from the second superposition lens 17 on the basis of image information and forming image light; and a projection optical system 6 projecting the image light.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a projector.

  The projector modulates light emitted from the light source unit according to image information with a light modulation device, and enlarges and projects the obtained image with a projection lens. In recent years, a laser light source such as a semiconductor laser capable of obtaining light with high luminance and high output has attracted attention as a light source of a light source device used in such a projector.

  For example, the following Patent Document 1 discloses a projector that uses blue diffused light generated by diffusing blue laser light and fluorescent light generated by making the laser light incident on a phosphor layer as excitation light as illumination light. Is disclosed. The projector includes a first integrator optical system for making the illuminance distribution of blue diffused light uniform, and a second integrator optical system for making the illuminance distribution of fluorescent light uniform.

JP 2013-228530 A

By the way, irradiating strong excitation light to a small region of the phosphor layer is not preferable because the light emission efficiency is lowered. Therefore, it is conceivable to make the intensity distribution of the excitation light uniform on the phosphor layer by arranging the third integrator optical system on the optical path of the excitation light.
However, in this case, since three integrator optical systems are required, the number of parts increases and the apparatus becomes larger.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a projector that can be miniaturized while suppressing a decrease in luminous efficiency.

  According to one aspect of the present invention, a light source unit that emits first light, a first lens array that the first light is incident on, and the first light that is transmitted through the first lens array are An incident second lens array, a light separating element that separates the first light transmitted through the second lens array into a first light bundle and a second light bundle, and the first light bundle A first superimposing lens on which is incident, a wavelength conversion element on which the first light beam emitted from the first superimposing lens is incident, a second superimposing lens on which the second light beam is incident, An image forming unit that modulates the second light emitted from the wavelength conversion element and the second light beam emitted from the second superimposing lens based on image information to form image light; and A projector including a projection optical system that projects image light is provided.

According to the configuration according to the above aspect, the illuminance distribution of the first light bundle that illuminates the wavelength conversion element is made uniform by the first superimposing lens, the first lens array, and the second lens array.
Further, the illuminance distribution of the second light bundle that illuminates the image forming unit is made uniform by the second superimposing lens, the first lens array, and the second lens array. The first lens array and the second lens array function as an integrator optical system that equalizes the illumination distributions of the wavelength conversion element and the image forming unit, respectively. Thereby, the integrator optical system is shared by the wavelength conversion element and the image forming unit. Therefore, the number of parts can be reduced by reducing the number of integrator optical systems.
In addition, since the wavelength conversion element can be illuminated uniformly, the wavelength conversion element can efficiently generate the second light.
Therefore, it is possible to reduce the size of the wavelength conversion element while reducing the decrease in the light emission efficiency.

In the above aspect, the wavelength conversion element further includes a reflection portion provided on the opposite side of the first superimposing lens, and the light separation element separates the first light and the second light. The second light may have a separation function, and may be transmitted through the first superimposing lens and incident on the image forming unit via the light separation element.
According to this configuration, the second light can be efficiently incident on the image forming unit. Therefore, the utilization efficiency of the second light can be increased.

In the above aspect, the aspect ratio of the spot formed on the wavelength conversion element by the first light flux may be substantially equal to the aspect ratio of the light incident area of the image forming unit.
In this way, as described above, it is possible to realize a structure in which the integrator optical system that makes the illuminance distribution of the first light bundle and the second light uniform is common.

In the above aspect, the wavelength conversion element and the spot may be relatively movable, and the relative movement may be performed along the short side direction of the spot.
According to this configuration, the amount of light per unit time of the first light bundle incident on the wavelength conversion element can be reduced as compared with the case of relative movement in the long side direction of the spot. Thereby, the rise in the temperature of the wavelength conversion element can be reduced, and the reduction in luminous efficiency can be reduced.

In the above aspect, the wavelength conversion element may be provided on a disc that rotates around a central axis, and a longitudinal direction of the spot may be parallel to a radial direction of the disc.
According to this configuration, the spot can be easily moved relative to the wavelength conversion element.

FIG. 2 is a plan view illustrating a schematic configuration of the projector according to the first embodiment. The perspective view which shows schematic structure of a light source array. The figure which shows the principal part structure of a light emission part. The perspective view which shows schematic structure of a collimating optical system. (A) is the side view which looked at FIG. 4 from -X direction, (b) is the top view which looked at FIG. 4 from + Z direction. The top view which looked at the 2nd lens array which concerns on a comparative example from + X direction. The top view which looked at the 2nd lens array from + X direction. The figure which showed notionally the light-incidence surface of a 1st lens array. (A) is a front view of a fluorescence light emitting element, (b) is sectional drawing by the A1-A1 line arrow of (a). The top view which shows schematic structure of the projector in 2nd Embodiment. The top view which shows schematic structure of the projector in 3rd Embodiment. The top view which shows schematic structure of the projector in 4th Embodiment.

(First embodiment)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.

(projector)
First, an example of the projector 1 shown in FIG. 1 will be described.
FIG. 1 is a plan view showing a schematic configuration of the projector 1.

  The projector 1 of the present embodiment is a projection type image display device that displays a color video on a screen SCR. The projector 1 uses three light modulation devices corresponding to each color light of red light LR, green light LG, and blue light LB. The projector 1 uses a semiconductor laser that can obtain light with high luminance and high output as the light source of the illumination device.

  Specifically, as shown in FIG. 1, the projector 1 includes an illumination device 2, a first total reflection mirror 7 a, a second total reflection mirror 7 b, a third total reflection mirror 7 c, and a dichroic mirror 8. A light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a combining optical system 5, and a projection optical system 6.

  The illumination device 2 emits blue light LB and yellow light YL.

  The dichroic mirror 8 has a function of separating the yellow light YL from the illumination device 2 into a red light LR and a green light LG. The dichroic mirror 8 transmits the separated red light LR and reflects the green light LG.

The first total reflection mirror 7a is disposed in the optical path of the blue light LB, and reflects the blue light LB emitted from the illumination device 2 toward the light modulation device 4B.
The second total reflection mirror 7b is disposed in the optical path of the green light LG, and reflects the separated green light LG toward the light modulation device 4G.
The third total reflection mirror 7c is disposed in the optical path of the red light LR, and reflects the separated red light LR toward the light modulation device 4R.

  The light modulation device 4R modulates the red light LR according to image information while allowing the red light LR to pass therethrough, and forms image light corresponding to the red light LR. The light modulation device 4G modulates the green light LG according to image information while allowing the green light LG to pass therethrough, and forms image light corresponding to the green light LG. The light modulation device 4B modulates the blue light LB according to image information while allowing the blue light LB to pass therethrough, and forms image light corresponding to the blue light LB. In the present embodiment, the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B correspond to an “image forming unit” recited in the claims.

  For example, a transmissive liquid crystal panel is used for the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. In addition, a pair of polarizing plates (not shown) are arranged on the incident side and the emission side of the liquid crystal panel so that only linearly polarized light in a specific direction passes therethrough.

  A field lens 9R, a field lens 9G, and a field lens 9B are disposed on the incident side of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, respectively.

  The combining optical system 5 combines the image light corresponding to the red light LR, the green light LG, and the blue light LB, and emits the combined image light toward the projection optical system 6. For example, a cross dichroic prism is used for the combining optical system 5.

  The projection optical system 6 is composed of a projection lens group. The projection optical system 6 enlarges and projects the image light combined by the combining optical system 5 toward the screen SCR. As a result, an enlarged color image is displayed on the screen SCR.

(Lighting device)
Next, the configuration of the lighting device 2 will be described.
The illumination device 2 includes a light source array 10, a collimating optical system 11, a first integrator optical system 12, a phase difference plate 13, a polarization separation element 14, a pickup optical system 15, a fluorescent light emitting element 16, and a blue color. The light superimposing lens 17, the total reflection mirror 18, the second integrator optical system 19, the polarization conversion element 20, the yellow light superimposing lens 21, and the total reflection mirror 22 are provided. In the following description, the optical axis of the light source array 10 is an optical axis ax1. An optical axis that is in the same plane as the optical axis ax1 and is orthogonal to the optical axis ax1 is defined as an optical axis ax2.

The light source array 10, the collimating optical system 11, the first integrator optical system 12, the phase difference plate 13, the polarization separation element 14, the pickup optical system 15, and the fluorescent light emitting element 16 are on the optical axis ax1. They are arranged side by side.
On the other hand, a total reflection mirror 18, a blue light superimposing lens 17, a polarization separating element 14, a second integrator optical system 19, a polarization conversion element 20, a yellow light superimposing lens 21, and a total reflection mirror 22 Are sequentially arranged on the optical axis ax2.

  FIG. 2 is a perspective view showing a schematic configuration of the light source array 10. The light source array 10 has a plurality of light emitting units 40. Hereinafter, in the description using the drawings, description will be made using the XYZ coordinate system. In FIG. 2, the X direction defines the arrangement direction of the light emitting units 40, the Y direction defines the principal ray direction of light emitted from the light emitting unit 40, and the Z direction is orthogonal to the X direction and the Y direction, respectively. And the vertical direction is defined.

  As shown in FIG. 2, the light source array 10 includes a main body portion 10A, a plurality of support members 10B, and a plurality of light emitting portions 40 supported by the support members 10B.

The main body 10A and the support member 10B are made of, for example, a metal material with excellent heat dissipation such as aluminum or copper.
The plurality of support members 10B are attached to the side surface 10A1 of the main body 10A. The support members 10B are arranged so that the intervals between the support members 10B are equal in the vertical direction of the side surface 10A1.

  Each support member 10B is a plate-like member and has an upper surface 10B1 and a lower surface 10B2. The planar shape of the upper surface 10B1 and the lower surface 10B2 is substantially rectangular, and has a long side in the X direction and a short side in the Y direction. The upper surface 10B1 is parallel to the XY plane and is a horizontal plane.

  In the present embodiment, the plurality of light emitting units 40 are each composed of a semiconductor laser. The plurality of light emitting units 40 are one-dimensionally mounted on the upper surface 10B1 of the support member 10B. The direction in which the plurality of light emitting units 40 are arranged is defined as a first direction (X direction). Each light emitting unit 40 emits a light beam BL composed of a blue light beam. The light source array 10 emits a light beam K including a plurality of light beams BL. In the present embodiment, the light beam K corresponds to “first light” in the claims.

FIG. 3 is a diagram illustrating a main configuration of the light emitting unit 40.
As shown in FIG. 3, the light emitting unit 40 has a light emitting surface 40a for emitting light. The light emission surface 40a has a substantially rectangular planar shape having a longitudinal direction W1 and a short direction W2 when viewed from the principal ray direction of the emitted light.

Here, the ratio of the width in the longitudinal direction W1 to the width in the short direction W2 of the light exit surface 40a (hereinafter sometimes referred to as an aspect ratio) is preferably 30: 1 or more. In the present embodiment, the width of the light emitting surface 40a in the longitudinal direction W1 is 40 μm, for example, and the width of the light emitting surface 40a in the short direction W2 is 1 μm, for example, but the shape of the light emitting surface 40a is limited to this. Not.
In FIG. 3, the longitudinal direction W1 is parallel to the X direction, and the lateral direction W2 is parallel to the Z direction.

  The light beam BL emitted from the light emitting unit 40 is composed of linearly polarized light having a polarization direction parallel to the longitudinal direction W1. The spread of the light beam BL in the short direction W2 is larger than the spread of the light beam BL in the longitudinal direction W1. In the present embodiment, the maximum value (maximum radiation angle) of the spreading angle of the light beam BL in the longitudinal direction W1 is 20 °, for example, and the maximum value (maximum radiation angle) of the spreading angle in the short direction W2 is 70 °, for example. It is.

  Therefore, the cross-sectional shape BS of the light beam BL has an elliptical shape with the Z direction (short direction W2) as the major axis direction.

  In the present embodiment, the plurality of light emitting units 40 are mounted on the upper surface 10B1 so that the principal ray BLa of the light beam BL emitted from each light emitting unit 40 is parallel to the Y direction. In other words, the principal ray of the light bundle K is parallel to the upper surface 10B1.

The light beam K emitted from the light source array 10 enters the collimating optical system 11.
As shown in FIG. 1, the collimating optical system 11 includes a first cylindrical lens array 50 and a second cylindrical lens array 55.

FIG. 4 is a perspective view showing a schematic configuration of the collimating optical system 11.
As shown in FIG. 4, the first cylindrical lens array 50 is disposed closer to the light source array 10 than the second cylindrical lens array 55. The first cylindrical lens array 50 includes a plurality of first cylindrical lenses 51. Note that each of the plurality of first cylindrical lenses 51 may be integrally formed, or may be configured separately.

The first cylindrical lens 51 has a first bus bar 51M along the X direction, a convex lens surface 52, and a flat back surface 53. First bus bar 51M is parallel to upper surface 10B1.
In the present embodiment, since the first cylindrical lens 51 is a plano-convex lens, the manufacturing cost can be reduced.

  In the present embodiment, the first cylindrical lens 51 has the back surface 53 opposed to the light emitting surface 40 a of each light emitting unit 40. The number of first cylindrical lenses 51 corresponds to the number of support members 10B.

  In the present embodiment, as shown in FIG. 2, since the support member 10 </ b> B is provided in five stages, the first cylindrical lens array 50 is composed of five first cylindrical lenses 51.

  Based on such a configuration, the light beam BL emitted from the light emitting unit 40 is collimated in the XZ plane by the corresponding first cylindrical lens 51.

  On the other hand, the second cylindrical lens array 55 includes a plurality of second cylindrical lenses 56. The second cylindrical lens array 55 includes a number of second cylindrical lenses 56 corresponding to the number of light emitting units 40 mounted on each support member 10B. Each of the plurality of second cylindrical lenses 56 may be integrally formed, or may be configured separately.

  The second cylindrical lens 56 is disposed so that the direction of the second bus bar 56M intersects the upper surface 10B1 of the support member 10B. In the present embodiment, the direction of the second bus bar 56M is orthogonal to the upper surface 10B1. In the second cylindrical lens 56, the second bus 56 </ b> M is orthogonal to the direction of the first bus 51 </ b> M of the first cylindrical lens 51.

  The second cylindrical lens 56 is a plano-convex lens having a convex lens surface 57 and a flat back surface 58.

In the present embodiment, the second cylindrical lens 56 has the back surface 58 opposed to the lens surface 52 of the first cylindrical lens 51. The number of second cylindrical lenses 56 corresponds to the number of light emitting units 40 arranged along the X direction of each upper surface 10B1.
In the present embodiment, as shown in FIG. 4, since the five light emitting portions 40 are arranged on the upper surface 10B1 of the support member 10B, the second cylindrical lens array 55 has five second cylindrical lenses 56. doing.

  Based on such a configuration, the light beam BL transmitted through the first cylindrical lens 51 is collimated in the XY plane by the corresponding second cylindrical lens 56.

FIG. 5 is a diagram for explaining the lens effect of the collimating optical system 11, FIG. 5 (a) is a side view of FIG. 4 viewed from the −X direction, and FIG. 5 (b) is FIG. 4 in the + Z direction. It is the top view seen from.
As shown in FIG. 5A, the first cylindrical lens 51 is emitted from the light emitting unit 40 by having a lens effect only in a plane parallel to the YZ plane orthogonal to the first generatrix 51M. The light beam BL is collimated in a plane parallel to the YZ plane. On the other hand, the first cylindrical lens 51 has no lens effect in a plane parallel to the XY plane parallel to the first bus 51M. Therefore, as shown in FIG. 5B, the light beam BL passes through the first cylindrical lens 51 without receiving the lens effect in a plane parallel to the XY plane.

In the present embodiment, in the cross section perpendicular to the first generatrix 51M of the first cylindrical lens 51, the cross-sectional shape of the lens surface 52 is an aspherical surface. In the present embodiment, the cross-sectional shape is a shape in which the conic constant T is approximated by -1 <T <0.
According to this configuration, since the spherical aberration can be corrected favorably, even when the spread angle of the light beam BL is large (70 °), the first cylindrical lens 51 can collimate well.

  As shown in FIG. 5A, the second cylindrical lens 56 has no lens effect in a plane parallel to the YZ plane parallel to the second generatrix 56M. Therefore, the light beam BL is a plane parallel to the YZ plane. It passes through the second cylindrical lens 56 without receiving any lens effect. On the other hand, as shown in FIG. 5B, the second cylindrical lens 56 has a lens effect in a plane parallel to the XY plane orthogonal to the second generatrix 56M, so that the light beam transmitted through the first cylindrical lens 51 is transmitted. BL is parallelized in a plane parallel to the XY plane.

  In the present embodiment, the distance between the first cylindrical lens 51 and the second cylindrical lens 56, the refractive power of the first cylindrical lens 51, and the refractive power of the second cylindrical lens 56 are determined by the second cylindrical lens 56. The aspect ratio of the cross section of the transmitted light beam BL is set to be approximately 1. That is, in the present embodiment, the cross-sectional shape BS of the light beam BL transmitted through the collimating optical system 11 is not an ellipse shown in FIG. 3 but a substantially circular shape.

  As described above, according to the present embodiment, the light bundle K emitted from the light source array 10 can be converted into parallel light by the collimating optical system 11 including two cylindrical lenses.

  The light beam K collimated by the collimating optical system 11 is incident on the first integrator optical system 12. The first integrator optical system 12 includes a first lens array 12a and a second lens array 12b. The first lens array 12a includes a plurality of first small lenses 12am, and the second lens array 12b includes a plurality of second small lenses 12bm. The plurality of second small lenses 12bm correspond to the plurality of first small lenses 12am, respectively. In the present embodiment, the first lens array 12a corresponds to the “first lens array” in the claims, and the second lens array 12b corresponds to the “second lens array” in the claims. .

  The first lens array 12a and the fluorescent light emitting element 16 are optically conjugate with each other, and the first lens array 12a and the light modulation device 4B are optically conjugate with each other. The light exit surface 40a of the light emitting unit 40 and the second lens array 12b are optically conjugate with each other.

  As will be described later, the first integrator optical system 12 cooperates with the pickup optical system 15 to uniformize the illuminance distribution (brightness) of the light that irradiates the fluorescent light-emitting element 16. Further, as described later, the first integrator optical system 12 cooperates with the blue light superimposing lens 17 to uniformize the illuminance distribution of light in the image forming region of the light modulation device 4B.

  By the way, in the illuminating device 2 having the light source array 10 including the plurality of light emitting units 40 as in the present embodiment, it is inevitable that a slight shift occurs in the alignment of the light emitting units 40. That is, in the present embodiment, the lighting device 2 has some mounting error.

  Here, as a comparative example, the configuration of the present embodiment will be described with reference to a homogenizer optical system 112 including a first lens array 112a and a second lens array 112b arranged at the subsequent stage.

FIG. 6 is a plan view of the second lens array 112b according to the comparative example viewed from the + Y direction.
When the mounting error occurs in the light source array 10, the uniformity of the illuminance distribution on the phosphor layer 34 decreases. This is because the position of the secondary light source image G formed on the second small lens 112bm by the light beam BL emitted from one light emitting unit 40 is a predetermined position of the second small lens 112bm, for example, the second small lens 112bm. This is because it is displaced from the center of

  Since the light exit surface 40a of the light emitting unit 40 and the second lens array 112b are optically conjugate, when the light exit surface 40a is a rectangle having a longitudinal direction in the X direction, it is formed on the second small lens 112bm. The secondary light source image G is a rectangle having a longitudinal direction in the X direction.

  Here, the movement of the secondary light source image G on the second small lens 112bm due to the mounting error occurs at the same rate in each direction. The planar shape of the second small lens 112bm is a square whose length in the X direction is equal to the length in the Z direction.

  When a mounting error occurs, the secondary light source image G deviates from a predetermined position. In the present embodiment, the plurality of light emitting units 40 are mounted on the upper surface 10B1 (horizontal plane) of the support member 10B. Therefore, mounting errors in the height direction (Z direction) orthogonal to the upper surface 10B1 are unlikely to occur in the plurality of light emitting units 40. However, on the upper surface 10B1, the mounting position of the light emitting unit 40 may be shifted in the X direction. In this case, the secondary light source image G is also shifted in the X direction.

  As can be seen from FIG. 6, the secondary light source image G shifted in the X direction may protrude from the second small lens 112bm. A component of the secondary light source image G that protrudes from the second small lens 112bm cannot irradiate a predetermined illuminated area. Therefore, when the secondary light source image G protrudes, the light bundle K emitted from the light source array 10 cannot be used efficiently, and the light use efficiency is lowered.

  Here, when the aspect ratio of the light emitting surface 40a of the light emitting unit 40 is, for example, 30: 1 or more, the secondary light source image G has an elongated shape in the longitudinal direction, so that the secondary light source image G is removed from the second small lens 112bm. Easy to protrude.

  In order to solve this problem, the illumination device 2 of the present embodiment includes the first integrator optical system 12 including the rectangular second small lens 12bm.

FIG. 7 is a plan view of the second lens array 12b viewed from the + Y direction.
As shown in FIG. 7, the planar shape of the second small lens 12bm of the second lens array 12b is a rectangle having a longitudinal direction along the X direction. Therefore, even if the secondary light source image G is shifted in the X direction due to a mounting error generated in the light emitting unit 40, the secondary light source image G is difficult to protrude from the second small lens 12bm.
Therefore, the light beam K emitted from the light source array 10 can be used efficiently. Further, since the mounting accuracy of the light emitting unit 40 required in the light source array 10 is lowered, the manufacturing is facilitated and the cost can be reduced.

  Further, according to the present embodiment, even when the aspect ratio of the light exit surface 40a is as large as, for example, 30: 1 or more and the secondary light source image G tends to protrude in the past, the protrusion of the secondary light source image G is reduced. be able to. The greater the aspect ratio of the light exit surface 40a, the more remarkable the present invention.

  The first cylindrical lens 51 has refractive power in the direction perpendicular to the upper surface 10B1, and the second cylindrical lens 56 has refractive power in the other direction. Further, since the second cylindrical lens 56 is disposed at the rear stage of the first cylindrical lens 51, the focal length of the second cylindrical lens 56 is longer than the focal length of the first cylindrical lens 51. Therefore, even when a mounting error of the light emitting unit 40 occurs in the first direction, the influence of the mounting error is relatively small.

  In order to improve the effect of the first integrator optical system 12, it is necessary to efficiently make the light beam BL incident on the first small lens 12am of the first lens array 12a. This is because the illuminance distribution in the illumination area is made uniform by superimposing the light incident on each first small lens 12am on the illumination area.

FIG. 8 is a diagram conceptually showing the light incident surface of the first lens array 12a. For comparison, FIG. 8 shows the light beam BL ′ when the aspect ratio is smaller than 1.
In the present embodiment, as described above, the aspect ratio of the cross-sectional shape BS of the light beam BL emitted from the collimating optical system 11 (second cylindrical lens 56) is approximately 1.

  As shown in FIG. 8, the light beam BL having an aspect ratio of the cross-sectional shape BS of approximately 1 has a larger incident area with respect to the first small lens 12am than the light beam BL ′ having an aspect ratio of the cross-sectional shape BS ′ smaller than 1. . Therefore, according to the present embodiment, it is possible to improve the light superimposing performance of the first integrator optical system 12.

Further, since the light beam BL has an aspect ratio of approximately 1 and a large area, the illuminated area can be illuminated with high uniformity without reducing the first small lens 12am. That is, since the number of first small lenses 12am constituting the first lens array 12a can be reduced, manufacturing is easy and the cost of the first lens array 12a can be reduced.
Therefore, according to the present embodiment, by setting the aspect ratio of the light beam BL to approximately 1, the illuminated area can be illuminated with high uniformity using the low-cost first integrator optical system 12.

The light beam K transmitted through the first integrator optical system 12 enters the phase difference plate 13.
The phase difference plate 13 is, for example, a half-wave plate that can be rotated. By appropriately setting the rotation angle of the half-wave plate, the light bundle K transmitted through the phase difference plate 13 is converted to light including an S-polarized component and a P-polarized component with respect to the polarization separation element 14 at a predetermined ratio. be able to. As described above, in the present embodiment, by rotating the phase difference plate 13, it is possible to arbitrarily change the ratio of the S polarization component and the P polarization component of the light emitted from the phase difference plate 13.

  The polarization separation element 14 is disposed so as to form an angle of 45 ° with respect to the optical axis ax1 and the optical axis ax2. The polarization separation element 14 is composed of, for example, a polarization beam splitter, and has a polarization separation function for separating the light beam K that has passed through the phase difference plate 13 into an S polarization component and a P polarization component. The polarization separation element 14 has a wavelength separation function of reflecting yellow light YL made of fluorescent light, which will be described later, having a wavelength band different from that of the light beam K, regardless of its polarization state.

Specifically, the polarization separation element 14 reflects the S-polarized light beam BLs of the incident light (light bundle K) and transmits the P-polarized light beam BLp of the incident light.
The light beam BLs that is the S-polarized component is reflected by the polarization separation element 14 and travels toward the blue light superimposing lens 17. The light beam BLp, which is a P-polarized component, passes through the polarization separation element 14 and travels toward the fluorescent light-emitting element 16.

  In the present embodiment, the polarization separation element 14 corresponds to a “light separation element” recited in the claims. The P-polarized component light beam BLp corresponds to the “first light bundle” described in the claims, and the S-polarized component light beam BLs corresponds to the “second light bundle” described in the claims. To do.

  The S-polarized light beam BLs reflected by the polarization separation element 14 enters the blue light superimposing lens 17. The blue light superimposing lens 17 corresponds to a “second superimposing lens” recited in the claims.

  The blue light superimposing lens 17 cooperates with the first integrator optical system 12 to superimpose the blue light LB (light rays BLs) on the image forming region of the light modulation device 4B, thereby uniformizing the illuminance distribution of the blue light LB. Turn into. Specifically, the blue light LB emitted from the blue light superimposing lens 17 enters the light modulation device 4B as blue light LB via the total reflection mirror 18, the first total reflection mirror 7a, and the field lens 9B. .

  According to the present embodiment, since the first integrator optical system 12 includes the rectangular second small lens 12bm, the blue light LB having a uniform brightness with respect to the image forming area of the light modulation device 4B can be efficiently obtained. Can be irradiated.

  On the other hand, the light beam BLp, which is a P-polarized component, passes through the polarization separation element 14 and enters the pickup optical system 15. The pickup optical system 15 has a function of condensing the light beam BLp on the phosphor layer 34 of the fluorescent light-emitting element 16 and a function of picking up and collimating the later-described fluorescence emitted from the phosphor layer 34.

  The pickup optical system 15 includes, for example, pickup lenses 15a and 15b. The pickup optical system 15 corresponds to a “first superimposing lens” recited in the claims, and the phosphor layer 34 corresponds to a “wavelength conversion element” recited in the claims.

  The pickup optical system 15 superimposes the light beam BLp on the phosphor layer 34 of the fluorescent light emitting element 16 in cooperation with the first integrator optical system 12. In the present embodiment, since the first integrator optical system 12 includes the rectangular second small lens 12bm, the phosphor layer 34 can be efficiently irradiated with the light beam BLp with uniform brightness as excitation light. it can.

  According to the present embodiment, the first integrator optical system 12 (the first lens array 12a and the second lens array 12b) can make the illuminance distribution in the phosphor layer 34 and the light modulation device 4B uniform. That is, in this embodiment, the integrator optical system is shared by the phosphor layer 34 and the light modulation device 4B. Therefore, the number of parts can be reduced by suppressing the number of integrator optical systems as compared with the case where the integrator optical systems are individually provided for the phosphor layer 34 and the light modulation device 4B.

FIG. 9 is a diagram showing a schematic configuration of the fluorescent light emitting element 16. FIG. 9A is a front view of the fluorescent light emitting element 16, and FIG. 9B is a cross-sectional view taken along line A1-A1 in FIG. 9A.
As shown in FIG. 9A, the fluorescent light emitting element 16 includes a phosphor layer 34, a disk 35 that supports the phosphor layer 34, and a drive unit 36. The disc 35 can be rotated around the rotation axis O by the drive unit 36. The disc 35 is made of a metal disc having excellent heat dissipation, such as aluminum or copper. The phosphor layer 34 is provided on the upper surface 35 a of the disc 35 along the circumferential direction of the disc 35. The drive part 36 is comprised from drive sources, such as a motor, for example.

  The phosphor layer 34 includes phosphor particles that absorb the light beam BLp, convert it into yellow light YL made of fluorescence, and emit it. As the phosphor particles, for example, YAG (yttrium / aluminum / garnet) phosphors can be used. In addition, the material for forming the phosphor particles may be one kind, or a mixture of particles formed using two or more kinds of materials may be used as the phosphor particles.

  For the phosphor layer 34, it is preferable to use a layer excellent in heat resistance and surface processability. As such a phosphor layer 34, for example, a phosphor layer in which phosphor particles are dispersed in an inorganic binder such as alumina, a phosphor layer in which phosphor particles are sintered without using a binder, and the like are preferably used. be able to.

  By the way, when the phosphor particles absorb the light beam BLp made of laser light and the temperature of the phosphor layer 34 rises excessively, a phenomenon called temperature quenching occurs, and the luminous efficiency of the phosphor particles decreases.

According to this embodiment, since the phosphor layer 34 is irradiated with the light beam BLp that has been made uniform by the first integrator optical system 12, the surface temperature of the phosphor layer 34 is prevented from excessively rising. Therefore, the light emission efficiency is unlikely to decrease.
Therefore, according to the present embodiment, it is possible to reduce the size of the apparatus by reducing the number of components as described above while reducing the decrease in the light emission efficiency of the yellow light YL.

  A reflective portion 37 is provided on the opposite side of the phosphor layer 34 from the side on which the light beam BLp is incident. The reflection unit 37 has a function of reflecting the yellow light YL generated by the phosphor layer 34 toward the pickup optical system 15 side.

  As described above, the first lens array 12a and the fluorescent light emitting element 16 are optically conjugate with each other, and the first lens array 12a and the light modulation device 4B are optically conjugate with each other. For this reason, the spot S formed on the phosphor layer 34 by the light beam BLp and the spot formed on the light modulation device 4B are similar to each other. That is, the aspect ratio of the spot S formed by the light beam BLp on the phosphor layer 34 is substantially equal to the aspect ratio of the image forming area of the light modulation device 4B.

In the present embodiment, the long side direction of the spot S coincides with the radial direction of the disc 35. Since the disk 35 rotates, the spot S moves relatively on the phosphor layer 34 in the short side direction of the spot S. Therefore, the light amount of the light beam BLp incident on a predetermined portion of the phosphor layer 34 per unit time (per time when the disk 35 makes one rotation) makes the short side direction of the spot S coincide with the radial direction of the disk 35. Less than the case.
Thereby, since the temperature rise of the phosphor layer 34 is reduced, temperature quenching hardly occurs, and the phosphor layer 34 can efficiently generate the yellow light YL.

  The yellow light YL emitted from the phosphor layer 34 is converted into parallel light by the pickup optical system 15 and then enters the polarization separation element 14. Since the polarization separation element 14 has a wavelength separation function, the yellow light YL is reflected by the polarization separation element 14 and enters the second integrator optical system 19. Thereby, the yellow light YL can be efficiently used, and the light modulation devices 4R and 4G can be illuminated well as described later.

  The second integrator optical system 19 cooperates with the yellow light superimposing lens 21 to uniformize the illuminance distribution by the yellow light YL in the illuminated area.

  The second integrator optical system 19 includes, for example, a lens array 19a and a lens array 19b. The lens arrays 19a and 19b are composed of a plurality of lenses arranged in an array.

  The yellow light YL that has passed through the second integrator optical system 19 enters the polarization conversion element 20. The polarization conversion element 20 includes, for example, a polarization separation film and a retardation plate, and converts yellow light YL into linearly polarized light.

  The yellow light YL that has passed through the polarization conversion element 20 enters the yellow light superimposing lens 21. The yellow light superimposing lens 21 superimposes the yellow light YL emitted from the polarization conversion element 20 on the illuminated area. In the present embodiment, the second integrator optical system 19 and the yellow light superimposing lens 21 make the illuminance distribution uniform in the illuminated area.

Specifically, the yellow light YL emitted from the yellow light superimposing lens 21 is reflected by the total reflection mirror 22 and separated by the dichroic mirror 8 into red light LR and green light LG. The red light LR passes through the dichroic mirror 8 and illuminates the image forming area of the light modulation device 4R with uniform brightness through the third total reflection mirror 7c and the field lens 9R.
The green light LG is reflected by the dichroic mirror 8 and the second total reflection mirror 7b, and then illuminates the image forming area of the light modulation device 4G with uniform brightness through the field lens 9G.

  As described above, according to the projector 1 of the present embodiment, the light emitted from the light source array 10 is efficiently incident on the fluorescent light emitting element 16 or the light modulation device 4B, so that high light utilization efficiency can be realized. Therefore, an image with excellent quality can be displayed with bright illumination light.

(Second Embodiment)
Next, the projector according to the second embodiment will be described. The difference between this embodiment and 1st Embodiment is the structure of an illuminating device. Below, the same code | symbol is attached | subjected about the member and structure which are common in 1st Embodiment, and the description is abbreviate | omitted or simplified.

FIG. 10 is a plan view showing a schematic configuration of the projector 1A of the present embodiment.
As shown in FIG. 10, the projector 1A includes an illumination device 2A, a first total reflection mirror 7a, a second total reflection mirror 7b, a third total reflection mirror 7c, a dichroic mirror 8A, and light modulation. A device 4R, a light modulation device 4G, a light modulation device 4B, a combining optical system 5, and a projection optical system 6 are provided.

  The lighting device 2A emits green light LG and purple light LP including red light LR and blue light LB.

  The dichroic mirror 8A has a function of separating the purple light LP from the illumination device 2A into red light LR and blue light LB. The dichroic mirror 8A transmits the separated blue light LB and reflects the red light LR.

Next, the configuration of the illumination device 2A will be described.
The illumination device 2A includes a light source array 110, a collimating optical system 11, a first integrator optical system 12, a phase difference plate 13, a polarization separation element 14A, a pickup optical system 15, a fluorescent light emitting element 116, and a purple color. The light superimposing lens 67, the total reflection mirror 68, the second integrator optical system 19, the polarization conversion element 20, the green light superimposing lens 21, and the total reflection mirror 22 are provided.

  In the present embodiment, the light bundle K1 emitted from the light source array 110 includes a first light BL1 composed of a plurality of blue beams and a second light BL2 composed of a plurality of red beams. The light source array 110 and the light source array 10 have the same basic configuration except that the color of the light beam emitted from the light emitting unit 40 is different. The first light BL1 corresponds to “first light” recited in the claims.

  The light beam K1 transmitted through the first integrator optical system 12 is incident on the phase difference plate 13.

  The polarization separation element 14A is composed of, for example, a polarization beam splitter, and has a polarization separation function for separating the first light BL1 that has passed through the phase difference plate 13 into an S-polarization component and a P-polarization component for the polarization separation element 14A. ing. Further, the polarization separation element 14A has a wavelength separation function, and the second light BL2 composed of green light LG composed of fluorescent light and the red beam, which will be described later, and has a wavelength band different from that of the first light BL1. Reflects regardless of the polarization state.

  Specifically, the polarization separation element 14A reflects the light beam BLs of the S polarization component and the second light BL2, and transmits the light beam BLp of the P polarization component.

The light beam BLp, which is a P-polarized component, passes through the polarization separation element 14A and enters the pickup optical system 15.
The pickup optical system 15 superimposes the light beam BLp on the phosphor layer 134 of the fluorescent light emitting element 116 in cooperation with the first integrator optical system 12. Since the first integrator optical system 12 has high light utilization efficiency and excellent superimposition characteristics, the phosphor layer 134 can be efficiently irradiated with the light beam BLp having uniform brightness as excitation light.

  In the present embodiment, the phosphor layer 134 includes phosphor particles that absorb the light beam BLp and emit green light LG made of fluorescence. The phosphor layer 134 corresponds to a “wavelength conversion element” recited in the claims.

  The green light LG emitted from the phosphor layer 134 is converted into parallel light by the pickup optical system 15. The green light LG that has passed through the pickup optical system 15 is reflected by the polarization separation element 14 </ b> A and enters the second integrator optical system 19. Thereby, the light modulation device 4G can be favorably illuminated with the green light LG.

  On the other hand, the light beam BLs and the second light BL2, which are S-polarized components, are reflected by the polarization separation element 14A and travel toward the purple light superimposing lens 67. The light beam BLs made of a blue beam and the second light BL2 made of a red beam apparently enter the violet light superimposing lens 67 as violet light LP. The purple light superimposing lens 67 corresponds to a “second superimposing lens” recited in the claims. The light beam BLs constitutes the blue light LB when the violet light LP is separated by the dichroic mirror 8A as will be described later, and the second light BL2 has the violet light LP formed by the dichroic mirror 8A as described later. When separated, it constitutes red light LR.

  The purple light superimposing lens 67 cooperates with the first integrator optical system 12 to superimpose the blue light LB on the light modulation device 4B and superimpose the red light LR on the light modulation device 4R. In the present embodiment, the illuminance distribution in the illuminated area is made uniform by the first integrator optical system 12 and the purple light superimposing lens 67.

The purple light LP emitted from the purple light superimposing lens 67 is reflected by the total reflection mirror 68 and enters the dichroic mirror 8A. The purple light LP is separated into red light LR and blue light LB by the dichroic mirror 8A. The blue light LB passes through the dichroic mirror 8A, and illuminates the light incident surface of the light modulation device 4B with uniform brightness through the first total reflection mirror 7a and the field lens 9B.
The red light LR is reflected by the dichroic mirror 8A and the third total reflection mirror 7c, and then illuminates the light incident surface of the light modulation device 4R with uniform brightness via the field lens 9R.

  According to the present embodiment, the first integrator optical system 12 (the first lens array 12a and the second lens array 12b) can make the illuminance distribution in the phosphor layer 134 and the light modulation device 4B uniform. That is, also in this embodiment, the integrator optical system is shared by the phosphor layer 134 and the light modulation device 4B. Therefore, the number of parts can be reduced by suppressing the number of integrator optical systems as compared with the case where the integrator optical systems are separately provided for the phosphor layer 134 and the light modulation device 4B.

  In the present embodiment, the illuminance distribution in the light modulation device 4 </ b> R can be made uniform by the first integrator optical system 12 and the violet light superimposing lens 67.

  As described above, according to the projector 1A of the present embodiment, the light emitted from the light source array 110 is efficiently incident on the fluorescent light emitting element 116 or the light modulation device 4B, so that high light utilization efficiency can be realized. Therefore, bright illumination light can be obtained. Therefore, an image with excellent quality can be displayed with bright illumination light.

(Third embodiment)
Next, the projector according to the third embodiment will be described. The difference between this embodiment and the said embodiment is a structure of an illuminating device. In the following, members and configurations common to those of the above embodiment are denoted by the same reference numerals, and descriptions thereof are omitted or simplified.

FIG. 11 is a plan view showing a schematic configuration of the projector 1B of the present embodiment.
As shown in FIG. 11, the projector 1B includes an illumination device 2B, a first total reflection mirror 7a, a second total reflection mirror 7b, a third total reflection mirror 7c, a dichroic mirror 8, and light modulation. A device 4R, a light modulation device 4G, a light modulation device 4B, a combining optical system 5, and a projection optical system 6 are provided.

  The illumination device 2B emits blue light LB and yellow light YL including red light LR and green light LG.

  The illumination device 2B includes a light source array 10, a collimating optical system 11, a first integrator optical system 12, a phase difference plate 13, a polarization separation element 14B, a blue light superimposing lens 17, and a total reflection mirror 18. , A pickup optical system 15, a fluorescent light emitting element 16, a second integrator optical system 19, a polarization conversion element 20, and a yellow light superimposing lens 23.

In the present embodiment, the light source array 10, the collimating optical system 11, the first integrator optical system 12, the phase difference plate 13, the polarization separation element 14B, the blue light superimposing lens 17, and the total reflection mirror 18 are provided. Are sequentially arranged on the optical axis ax1.
On the other hand, the fluorescent light-emitting element 16, the pickup optical system 15, the polarization separation element 14B, the second integrator optical system 19, the polarization conversion element 20, and the yellow light superimposing lens 23 are sequentially arranged on the optical axis ax2. They are arranged side by side.

  In the present embodiment, the polarization separation element 14B has an optical characteristic of transmitting the yellow light YL regardless of the polarization state. The light beam BLs that is the S-polarized component is reflected by the polarization separation element 14 and travels toward the fluorescent light-emitting element 16. The light beam BLp, which is a P-polarized component, passes through the polarization separation element 14 and travels to the blue light superimposing lens 17 as blue light LB.

  Also in the projector 1B of the present embodiment, since the integrator optical system can be shared with the phosphor layer 34 and the light modulation device 4B, the number of components can be reduced. Further, since the light emitted from the light source array 10 is efficiently incident on the fluorescent light emitting element 16 or the light modulation device 4B, the light use efficiency is high, and an image with excellent quality can be displayed with bright illumination light.

(Fourth embodiment)
Next, the projector according to the fourth embodiment will be described. The difference between this embodiment and the said embodiment is a structure of an illuminating device. In the following, members and configurations common to those of the above embodiment are denoted by the same reference numerals, and descriptions thereof are omitted or simplified.

FIG. 12 is a plan view showing a schematic configuration of the projector 1C according to the present embodiment.
As shown in FIG. 12, the projector 1C includes an illumination device 2C, a first total reflection mirror 7a, a second total reflection mirror 7b, a third total reflection mirror 7c, a dichroic mirror 8, and light modulation. A device 4R, a light modulation device 4G, a light modulation device 4B, a combining optical system 5, and a projection optical system 6 are provided.

  The lighting device 2C emits blue light LB and yellow light YL including red light LR and green light LG.

  The illumination device 2C includes a light source array 10, a collimating optical system 11, a first integrator optical system 12, a phase difference plate 13, a polarization separation element 14, a fluorescent superimposing lens 25, a fluorescent light emitting element 216, A pickup lens 26, a second integrator optical system 19, a polarization conversion element 20, a yellow light superimposing lens 23, a blue light superimposing lens 17, and a total reflection mirror 18 are provided.

In the present embodiment, the light source array 10, the collimating optical system 11, the first integrator optical system 12, the phase difference plate 13, the polarization separation element 14, the fluorescent superimposing lens 25, the fluorescent light emitting element 216, The pickup lens 26, the second integrator optical system 19, the polarization conversion element 20, and the yellow light superimposing lens 23 are sequentially arranged on the optical axis ax1.
On the other hand, the polarization separation element 14, the blue light superimposing lens 17, and the total reflection mirror 18 are sequentially arranged on the optical axis ax2.

  In this embodiment, the light beam BLp, which is a P-polarized component with respect to the polarization separation element 14, passes through the polarization separation element 14 and enters the fluorescence superimposing lens 25. The light beam BLs that is the S-polarized component with respect to the polarization separation element 14 is reflected by the polarization separation element 14 and travels to the blue light superimposing lens 17 as the blue light LB.

  In the fluorescent light emitting device 216 of the present embodiment, the circular plate 35A that supports the phosphor layer 34 is composed of a light transmissive member. Therefore, the fluorescent superimposing lens 25 cooperates with the first integrator optical system 12 to superimpose the light beam BLp on the phosphor layer 34 of the fluorescent light emitting element 216 from the back surface side of the circular plate 35A. The fluorescent superimposing lens 25 corresponds to a “first superimposing lens” recited in the claims.

  Also in the present embodiment, by using the first integrator optical system 12, the illuminance distribution in the phosphor layer 34 and the light modulation device 4B can be made uniform. That is, the number of parts can be reduced by sharing the integrator optical system with respect to the phosphor layer 34 and the light modulation device 4B.

  The phosphor layer 34 emits yellow light YL toward the pickup lens 26. The pickup lens 26 picks up and collimates the yellow light YL emitted from the phosphor layer 34.

  The yellow light YL collimated by the pickup lens 26 enters the second integrator optical system 19. The yellow light YL passes through the yellow light superimposing lens 23 and is separated into red light LR and green light LG by the dichroic mirror 8. The red light LR and the green light LG illuminate the light incident surfaces of the light modulation devices 4R and 4G with uniform brightness.

  Also in the projector 1C of the present embodiment, since the integrator optical system can be shared with the phosphor layer 34 and the light modulation device 4B, the number of parts can be reduced. In addition, since the light emitted from the light source array 10 is efficiently incident on the fluorescent light emitting element 216 or the light modulation device 4B, the light use efficiency is high, and an image with excellent quality can be displayed with bright illumination light.

In addition, although one embodiment of the present invention has been illustrated and described, the present invention is not necessarily limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. It is.
For example, the direction of the first bus bar 51M and the direction of the second bus bar 56M do not necessarily have to be orthogonal.

  In the above-described embodiment, the projectors 1, 1A, 1B, and 1C including the three light modulation devices 4R, 4G, and 4B are exemplified. However, the present invention can be applied to a projector that displays a color image with one light modulation device. It is. Furthermore, the light modulation device is not limited to the above-described liquid crystal panel, and for example, a digital mirror device can be used.

1, 1A, 1B, 1C ... projector, 2, 2A, 2B, 2C ... illumination device, 4B, 4G, 4R ... light modulation device, 6 ... projection optical system, 10, 110 ... light source array, 12a, 112a ... first Lens array, 12b, 112b ... second lens array, 15 ... pickup optical system, 17 ... blue light superimposing lens, 20 ... polarization conversion element, 34 ... phosphor layer, 35, 35A ... disc, 37 ... reflecting part, 67 ... Superimposing lens for purple light, BLp ... light, BLs ... light, BL1 ... first light, BL2 ... second light, S ... spot.

Claims (5)

A light source unit that emits first light;
A first lens array on which the first light is incident;
A second lens array on which the first light transmitted through the first lens array is incident;
A light separation element that separates the first light transmitted through the second lens array into a first light bundle and a second light bundle;
A first superimposing lens on which the first light beam is incident;
A wavelength conversion element on which the first light beam emitted from the first superimposing lens is incident;
A second superimposing lens on which the second light beam is incident;
An image forming unit that modulates the second light emitted from the wavelength conversion element and the second light flux emitted from the second superimposing lens based on image information to form image light;
A projection optical system that projects the image light. A reflection unit provided on the opposite side of the wavelength conversion element from the first superimposing lens;
The light separation element has a wavelength separation function of separating the first light and the second light,
The projector according to claim 1, wherein the second light is transmitted through the first superimposing lens and is incident on the image forming unit via the light separation element. The projector according to claim 1, wherein an aspect ratio of a spot formed by the first light beam on the wavelength conversion element is substantially equal to an aspect ratio of a light incident area of the image forming unit. The wavelength conversion element and the spot are relatively movable,
The projector according to claim 3, wherein the relative movement is performed along a short side direction of the spot. The wavelength conversion element is provided on a disk that rotates around a central axis,
The projector according to claim 4, wherein a longitudinal direction of the spot is parallel to a radial direction of the disc.

Images