JP2015108758A - Illumination apparatus, projection type video display device, illumination method, and projection type video display method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination apparatus, a projection type video display device, an illumination method, and a projection type video display method, which can guide light from a fluorescent body to a light modulation element efficiently.SOLUTION: An illumination apparatus 100 generates illumination light, which is not subjected to polarization conversion, using: an excitation light source unit 101 that emits excitation light; a fly-eye lens pair 108 for excitation light, that divides a light flux of the excitation light into a plurality of partial light fluxes; a condensing optical system 110 that condenses the plurality of partial light fluxes of the excitation light into a rectangular light spot; a fluorescent body 111 that emits illumination light by the excitation light condensed by the condensing optical system 110; and a fly-eye lens pair 117 for illumination light, that divides a light flux of illumination light into a plurality of partial light fluxes.

Description

  The present invention relates to an illumination device, a projection video display device, an illumination method, and a projection video display method. For example, the present invention relates to a technique for efficiently guiding light emitted from a phosphor to a light modulation element.

  Conventionally, by irradiating a phosphor with laser light or the like as excitation light, an illumination device that outputs light generated by the phosphor as illumination light, and optically modulating the illumination light to generate image light, A projection-type image display device that projects this image light is known.

  For example, in Patent Document 1, an elliptical condensing surface is formed on a phosphor by providing an anisotropic diffusion plate in the optical path of excitation light, and the shape of this condensing surface is changed to a fly-eye lens in the subsequent stage. A configuration similar to the shape of the incident surface of a polarizing beam splitter (that is, a polarization conversion element) disposed in combination with the above is disclosed. Thereby, the utilization efficiency of illumination light can be improved. Note that the fly-eye lens is an element that equalizes the luminance distribution of illumination light. The polarization conversion element is an element for converting illumination light into polarized light that can be transmitted through a transmissive liquid crystal panel as a light modulation element.

  Further, Patent Document 1 discloses a configuration in which a fly-eye lens and a polarization conversion element are removed and a rod integrator is used instead when a DMD (Digital Micromirror Device) is used as a light modulation element instead of a liquid crystal. ing. This is because the light reflected by the DMD does not need to be polarized light and does not require a polarization conversion element.

  Patent Document 2 discloses a configuration in which a fly-eye lens is provided in the optical path of excitation light. Thereby, since excitation light can be irradiated with uniform intensity | strength with respect to fluorescent substance, local light saturation can be suppressed and the emitted light intensity fall of fluorescent substance can be suppressed.

JP2013-120250A JP 2013-114980 A

  Conventionally, when a light modulation element that does not require a polarization conversion element, such as a DMD, is to be adopted, light is transmitted to the front stage of the light modulation element by a rod integrator having a configuration described in Patent Document 1 or several mirrors. It is common to have a mirror tunnel that mixes the angular distribution of light by multiple reflection.

  However, since the rod integrator and mirror tunnel require a certain mounting space, they have become barriers to downsizing the apparatus.

  In addition, it is desired to employ an element that has a function of uniforming the luminance distribution of illumination light and that can achieve better optical efficiency than the case of using a rod integrator or a mirror tunnel.

  The present invention has been made to solve such problems, and an illumination device, a projection-type image display device, an illumination method, and an illumination device capable of efficiently guiding light emitted from a phosphor to a light modulation element, and An object of the present invention is to provide a projection type image display method.

  Other problems and novel features will become apparent from the description of the specification and the accompanying drawings.

  An illumination device according to the present invention includes an excitation light source unit that emits excitation light, a pair of excitation light fly-eye lenses that divides the beam bundle of excitation light into a plurality of partial beam bundles, and a plurality of partial beams of the excitation light. A condensing optical system that condenses the bundle into a rectangular condensing spot, a phosphor that emits illumination light by the excitation light condensed by the condensing optical system, and a bundle of light beams of the illumination light. The illumination light that has not undergone polarization conversion is generated by the pair of fly-eye lenses for illumination light that is divided into light bundles.

  The projection type video display device according to the present invention includes the illumination device and a light modulation element that modulates the illumination light generated by the illumination device and not subjected to polarization conversion.

  In the illumination method according to the present invention, the excitation light source unit emits excitation light, the excitation light fly-eye lens pair divides the beam bundle of the excitation light into a plurality of partial beam bundles, An optical system condensing a plurality of partial beam bundles of the excitation light into a rectangular condensing spot; and a phosphor emitting illumination light by the excitation light condensed by the condensing optical system Then, the illumination light fly-eye lens pair generates the illumination light that has not undergone polarization conversion by dividing the light flux of the illumination light into a plurality of partial light fluxes.

  The projection-type image display method according to the present invention includes the illumination method and a step in which a light modulation element modulates the illumination light generated by the illumination method and not subjected to polarization conversion.

  According to the present invention, it is possible to provide an illumination device, a projection image display device, an illumination method, and a projection image display method that can efficiently guide light emitted from a phosphor to a light modulation element.

It is a figure which shows the structure of the projection type video display apparatus 100 concerning embodiment of this invention. It is a figure which shows the example of the phosphor wheel 111 concerning embodiment of this invention. It is a figure which shows the example of the fly eye lens for lasers and the fly eye lens 117 concerning embodiment of this invention. It is a figure which shows the example of the excitation light condensing spot concerning embodiment of this invention.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. First, the configuration of a projection display apparatus 100 according to an embodiment of the present invention will be described with reference to FIG.

  The projection display apparatus 1000 includes an illumination apparatus 100 that outputs illumination light and a light modulation element 200 that modulates the illumination light to generate image light.

  The illumination device 100 includes an optical system for guiding excitation light to the phosphor, a phosphor that generates the illumination light upon receiving the excitation light, and the excitation light transmitted through the transmission region of the illumination light and the phosphor wheel 111 as the light modulation element 200. Including an optical system.

  The optical system for guiding the excitation light to the phosphor is a semiconductor laser 101 composed of a plurality of semiconductor laser arrays as an excitation light source, a collimator lens array 102 for collimating the emitted light of the semiconductor laser 101, and all the parallel light is the same. The mirror array 103 provided so as to guide in the direction, the afocal lens 104 constituting the afocal optical system, the mirror 105, the afocal lens 106, the diffusion plate 107 that diffuses the excitation light to a certain degree, and the function as an integrator of the excitation light. The laser fly-eye lens 108 includes a dichroic mirror 109 that reflects only excitation light and transmits other light, and a condenser lens 110 that condenses the excitation light.

  The phosphor wheel 111 as a phosphor has a red phosphor, a green phosphor, and a blue transmission region that transmits excitation light (FIG. 2).

  An optical system for guiding the illumination light and the excitation light transmitted through the phosphor wheel 111 to the light modulation element 200 includes a blue light collimator lens 112 for guiding the excitation light transmitted through the phosphor wheel to the illumination system as blue light, Mirror 113, blue light collimator lens array 114, mirrors 115 and 116, fly-eye lens 117 having a function as an illumination light integrator, condenser lens 118 for guiding light from fly-eye lens 117 to the light modulation element, mirror 119, A condenser lens 120 and a total internal reflection (TIR) prism 121 are included.

  The light modulation element 200 in the present embodiment is a light modulation element that does not require prior polarization conversion, and is, for example, a DMD. A projection lens for projecting image light onto the projection surface may be provided at the subsequent stage of the DMD 200.

  Here, in this embodiment, as shown in FIG. 3, the aspect ratios (ratio of long side to short side) of all fly eye lens cells of the fly eye lens for laser 108 and the fly eye lens 117 are substantially the same. Degree. Specifically, the cell size of the fly eye lens 117 is 6.8 mm × 3.8 mm, the cell size of the fly eye lens 108 for laser is 2.5 mm × 1.4 mm, and the like.

  Furthermore, in the present embodiment, as shown in FIG. 3, the angle θ formed by the long side of the cell of the fly-eye lens 117 and the XZ plane that is a plane parallel to the optical path, and the fly-eye lens for laser 108 The angle θ formed by the long side of the cell and the XZ plane is the same. Specifically, the angle θ formed between the long side of the cell of the fly-eye lens 117 and the laser fly-eye lens 108 and the XZ plane is set to 36 degrees.

  In the present embodiment, as shown in FIG. 4, the center of the phosphor wheel 111 and the center of the excitation light condensing spot (that is, the rectangular range irradiated with the excitation light) on the phosphor wheel 111 are The connecting line is parallel to the long side direction of the excitation light condensing spot.

  Further, the shape of the excitation light condensing spot is similar to the shape of the cell of the laser fly-eye lens 108. Furthermore, the angle θ formed by the long side of the excitation light condensing spot and the XZ plane is the same as the angle θ formed by the long side of the cell of the laser fly-eye lens 108 and the XZ plane.

  Further, the shape of the excitation light condensing spot and the shape of the cell of the fly-eye lens 117 are similar. Further, the angle θ formed by the long side of the excitation light condensing spot and the XZ plane is the same as the angle θ formed by the long side of the cell of the fly-eye lens 117 and the XZ plane.

  That is, when the laser fly-eye lens 108 and the fly-eye lens 117 are viewed through the condenser lens 110 from the excitation light condensing spot that is the focal point of the condenser lens 110, the laser fly-eye lens 108 and the fly-eye lens are observed. The lens 117 is the same.

  The operation of the projection display apparatus 1000 according to the first embodiment will be described next.

  First, the semiconductor laser 101 emits laser light. This laser light becomes excitation light for generating illumination light in the phosphor wheel 111 at the subsequent stage.

  Next, the collimator lens array 102 converts the emitted laser light into parallel light.

  In the present embodiment, the semiconductor laser 101 is composed of two semiconductor laser arrays arranged in different directions. Therefore, the mirror array 103 reflects only the emitted light from one semiconductor laser array in the same direction as the emitted light from the other semiconductor laser array. Thereby, the laser beams emitted from all the semiconductor laser arrays are guided in the same direction.

  The afocal lens 104 is a lens that forms an afocal optical system, and receives parallel laser light and emits parallel light having different beam diameters. Light emitted from the afocal lens 104 reaches the diffusion plate 107 through the mirror 105 and the afocal lens 106. The diffusion plate 107 diffuses the incident laser light about once and makes it enter the laser fly-eye lens 108.

  As shown in FIG. 3, the laser fly-eye lens 108 is composed of a plurality of rectangular lenses (fly eye cells) arranged in a matrix. Each of these fly eye lenses spatially divides the incident laser light. In other words, the light bundle of excitation light is divided into a plurality of partial light bundles. By mixing this with the condensing lens 110 in the subsequent stage, it is possible to generate excitation light with no bias in light intensity.

  The dichroic mirror 109 is a mirror that reflects only excitation light and transmits other light, that is, illumination light. The excitation light emitted from the laser fly-eye lens 108 is reflected toward the phosphor wheel 111 by the dichroic mirror 109.

  The condensing lens 110 condenses the partial light beam of the excitation light and focuses it on the excitation light condensing spot on the phosphor wheel 111.

  As shown in FIG. 2, the phosphor wheel 111 includes a plurality of regions divided in the circumferential direction, a red phosphor region 1111 coated with a red phosphor, and a green phosphor coated with a green phosphor. A region 1112 and a blue transmission region 1113 that transmits excitation light are provided. Further, as shown in FIG. 4, an excitation light condensing spot irradiated with excitation light exists on the phosphor wheel 111. The phosphor wheel 111 rotates about the wheel center, and any one of the red phosphor region 1111, the green phosphor region 1112, and the blue transmission region 113 is collected according to the timing when the excitation light is irradiated. Superimpose on the light spot. When the red phosphor region 1111 or the green phosphor region 1112 and the excitation light condensing spot overlap, red or green fluorescence is excited. On the other hand, when the blue transmissive region 113 and the excitation light condensing spot overlap, the excitation light passes through the phosphor wheel 111. These red, green fluorescence, and blue laser lights serve as illumination light for causing the DMD 200 in the subsequent stage to generate image light.

  Here, as shown in FIG. 4, the excitation light condensing spot is the center of the phosphor wheel 111 and the center of the excitation light condensing spot on the phosphor wheel 111 (that is, a rectangular range irradiated with the excitation light). Are set parallel to the long side direction of the excitation light condensing spot. That is, a rectangular region that is long in the radiation direction and short in the circumferential direction on the phosphor wheel 111 is used as an excitation light condensing spot. As a result, the spoke time at the time of color switching can be shortened to prevent the display image from being degraded. That is, when the phosphor wheel 111 crosses the transmission region with the phosphors of different colors or the phosphors in the middle of rotation, measures are taken such as turning off the excitation light source in order to avoid color mixing and deterioration of color purity. However, it is possible to shorten the turn-off period (spoke time).

  The shape of the excitation light condensing spot is similar to the shape of the cell of the laser fly-eye lens 108, and the angle θ with the XZ plane is the same. Thereby, the application area of the phosphor on the phosphor wheel 111 can be minimized.

  The excited red or green fluorescence is incident on the condenser lens 110 in the opposite direction to the previous time, and reaches the dichroic mirror 109. The dichroic mirror 109 transmits fluorescence and enters the fly-eye lens 117.

  On the other hand, the blue excitation light transmitted through the phosphor wheel 111 is guided to the dichroic mirror 109 via the blue light collimator lens 112, the mirror 113, the blue light collimator lens array 114, and the mirrors 115 and 116. The dichroic mirror 109 reflects the excitation light and makes it enter the fly-eye lens 117.

  The fly-eye lens 117 is composed of a plurality of rectangular lenses (fly eye cells) arranged in a matrix like the laser fly-eye lens 108. The red, green, or blue illumination light incident on the fly-eye lens 117 is spatially divided by each one of these fly-eye lenses. In other words, the illumination light is divided into a plurality of partial beam bundles. By mixing this with the subsequent condenser lenses 118 and 120, it is possible to generate illumination light with no bias in light intensity.

  Here, the shape of the cell of the fly-eye lens 117 is similar to the shape of the excitation light condensing spot on the phosphor wheel 111, and the angle θ with the XZ plane is the same. Thereby, the fluorescence excited in the excitation light condensing spot enters the fly-eye lens 117 without being missed. Therefore, optical efficiency can be improved.

  By the way, conventionally, a light tunnel, a rod integrator, or the like has been generally used for the purpose of making the illumination light uniform before the DMD 200. A light tunnel is an element that mixes the angular distribution of light by multiple reflection of light by a plurality of mirrors arranged in a cylindrical housing. The rod integrator is an element made of a square bar such as glass and mixing the angular distribution of light as in the light tunnel.

  However, the inventor has found that the optical efficiency is improved as a whole by adopting the fly-eye lens 117 instead of the light tunnel or the rod integrator.

  When a light tunnel or a rod integrator is used, the light tunnel or the rod integrator has a small entrance. Therefore, it is necessary to arrange a condenser lens or the like before the incident light. On the other hand, the fly-eye lens 117 does not require a condensing lens or the like. For this reason, if a fly-eye lens 117 is used instead of the light tunnel or the rod integrator, the mounting space and the manufacturing cost can be reduced.

  Illumination light emitted from the fly-eye lens 117 is superimposed by the condenser lenses 118 and 120, and is uniformly illuminated on the DMD 200 via the TIR prism 121.

  According to the present embodiment, the laser fly-eye lens 108, the phosphor wheel 111, and the fly-eye lens 117, which are in a conjugate relationship, have similar shapes, and thus light can be efficiently guided to the DMD 200. Further, the spoke time and the phosphor coating area can be suppressed.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 Illuminating device 101 Semiconductor laser 102 Collimator lens array 103 Mirror array 104 Afocal lens 105 Mirror 106 Afocal lens 107 Diffusing plate 108 Fly eye lens for laser 109 Dichroic mirror 110 Condensing lens 111 Phosphor wheel 112 Collimator lens 113 for blue light Mirror 114 Blue light collimator lens array 115 Mirror 116 Mirror 117 Fly eye lens 118 Condenser lens 119 Mirror 120 Condenser lens 121 TIR prism 200 Light modulation element (DMD)
1000 Projection-type image display device

Claims (10)

An excitation light source that emits excitation light;
A pair of fly-eye lenses for excitation light that divides the light bundle of the excitation light into a plurality of partial light bundles;
A condensing optical system for condensing a plurality of partial beam bundles of the excitation light into a rectangular condensing spot;
A phosphor that emits illumination light by the excitation light collected by the condensing optical system;
An illumination device that generates the illumination light that has not undergone polarization conversion, with a pair of fly-eye lenses for illumination light that divides the light bundle of the illumination light into a plurality of partial light bundles. The illumination device according to claim 1, wherein an aspect ratio of the excitation light fly-eye lens pair and an aspect ratio of the illumination light fly-eye lens pair are substantially the same. When the excitation light fly-eye lens pair and the illumination light fly-eye lens pair are viewed from the focal point of the condenser lens through the condenser lens, the length of the fly-eye lens for excitation light The lighting device according to claim 1, wherein a side direction is the same as a long side direction of the fly-eye lens for illumination light. The phosphor is a phosphor wheel in which the circumferential direction of the rotatable wheel is divided by a plurality of phosphors,
The illuminating device according to any one of claims 1 to 3, wherein a line connecting a center of the phosphor wheel and a center of the condensing spot on the phosphor wheel is parallel to a long side direction of the condensing spot. . The lighting device according to any one of claims 1 to 4,
A light modulation element that modulates the illumination light generated by the illumination device and not subjected to polarization conversion, and a projection-type image display device. An excitation light source unit emitting excitation light;
A pair of excitation light fly-eye lenses divides the beam bundle of the excitation light into a plurality of partial beam bundles;
A condensing optical system condensing the plurality of partial light bundles of the excitation light into a rectangular condensing spot;
A phosphor emitting illumination light by the excitation light collected by the condensing optical system;
An illumination method in which a pair of illumination light fly-eye lenses divides a beam bundle of the illumination light into a plurality of partial beam bundles to generate the illumination light that has not undergone polarization conversion. The illumination method according to claim 6, wherein an aspect ratio of the pair of excitation light fly-eye lenses and an aspect ratio of the pair of illumination light fly-eye lenses are substantially the same. When the excitation light fly-eye lens pair and the illumination light fly-eye lens pair are viewed from the focal point of the condenser lens through the condenser lens, the length of the fly-eye lens for excitation light The illumination method according to claim 6 or 7, wherein a side direction is the same as a long side direction of the fly-eye lens for illumination light. The phosphor is a phosphor wheel in which the circumferential direction of the rotatable wheel is divided by a plurality of phosphors,
The illumination method according to any one of claims 6 to 9, wherein a line connecting the center of the phosphor wheel and the center of the condensing spot on the phosphor wheel is parallel to a long side direction of the condensing spot. . An illumination method according to any one of claims 6 to 9,
A light modulation element that modulates the illumination light that has been generated by the illumination method and has not undergone polarization conversion, and a projection-type image display method.