JP4082160B2 - Prism and projection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a prism that separates illumination light emitted from a light source in accordance with the wavelength or polarization component, and modulates the illumination light emitted from the light source using a reflective light modulation element, and magnifies the projection using a lens. Projection device And Related.
[0002]
[Prior art]
Conventionally, in order to enable a large screen display, illumination light is irradiated from a lamp to a liquid crystal panel on which a pattern corresponding to an input video signal is displayed, and the liquid crystal panel modulates and reflects the reflected light. There is a projection apparatus that performs enlarged projection using a projection lens.
[0003]
In this projector, a polarizing beam splitter (hereinafter referred to as PBS: Polarized Beam) that separates the forward path and the return path in the optical path so that the illumination light to the liquid crystal panel and the reflected light modulated by the liquid crystal panel do not have the same optical path. Called Splitter). As shown in FIG. 10, the PBS 200 has a structure in which a pair of corner prisms 202 serving as a base material are bonded so as to sandwich the dielectric multilayer film 201. The PBS 200 is formed such that the dielectric multilayer film 201 has different reflectance and transmittance according to the wavelength or polarization direction of light, and functions as a beam splitter that separates the light flux according to the wavelength or polarization direction ( For example, see Patent Document 1.)
[0004]
The PBS 200 as described above can be classified into a McNile type in which the dielectric multilayer film 201 separates the light beam according to the polarization component, and a dichroic type that separates the light beam according to the wavelength.
[0005]
In PBSs that use interference of dielectric multilayer films, such as McNile type and dichroic type, the performance is determined by the combination of the refractive index of the substrate and the dielectric material to be laminated, and there is a limit to the desired performance . For example, with such a PBS, it is very difficult to maintain the separation characteristics of P-polarized light and S-polarized light at a wide incident angle. For this reason, when this PBS is incorporated in an optical system having a large angular distribution, that is, a small F value, the separation characteristics are poor and the light utilization efficiency is also deteriorated.
[0006]
As a solution, a flat diffraction grid PBS 210 as shown in FIG. 11 can be used (see, for example, Patent Document 2). In such a diffraction grid PBS 210, for example, a grid-like diffraction grid 212 formed of aluminum or the like is provided on a glass substrate 211, and the diffraction grid 212 separates light according to a polarization component.
[0007]
[Patent Document 1]
JP 2000-147246 A
[Patent Document 2]
JP 11-6989 A (6th page, FIG. 12)
[0008]
[Problems to be solved by the invention]
However, when the above-described diffraction grid 212 is used as a beam splitter, it is necessary to dispose the diffraction grid PBS 210 obliquely with respect to the chief ray, and therefore, when entering the optical path of the imaging optical system. Will cause astigmatism.
[0009]
In addition, when using a McNile type or dichroic type prism, light is transmitted through the base material due to distortion in the prism caused by a rise in temperature of the prism or a holding mechanism, and a non-uniform refractive index distribution of the base material. A phase difference occurs, and the extinction ratio is partially deteriorated by this influence. In a projection apparatus using such a prism, so-called black unevenness occurs in the projected image, and a clear image cannot be projected.
[0010]
For this reason, it is necessary to select a material having a low optical elastic constant that hardly causes distortion inside the prism as the base material of the prism. However, a material having a low optical elastic constant is expensive, and the cost of the prism using the material having such a low optical elastic constant, and the entire projection apparatus using the prism is also high. Moreover, it is very difficult to produce a prism with good performance with an inexpensive glass material having a high optical elastic constant.
[0011]
Accordingly, the present invention has been made in view of the above-described problems, and is a prism that suppresses the generation of astigmatism and has a uniform refractive index distribution of the base material. And using this An object is to provide a projection device.
[0012]
[Means for Solving the Problems]
A prism according to the present invention is a prism that transmits or reflects incident light in accordance with a polarization component, and includes a substantially grid-shaped diffraction grid formed of metal, and a pair of diffraction grid base materials sandwiching the diffraction grid. An adhesive layer provided on each surface side facing the diffraction grid of the pair of diffraction grid base materials, and a pair of block members respectively fixed to the pair of diffraction grid base materials via the adhesive layer, A space formed by the diffraction grid and the pair of diffraction grid base materials is filled with a medium having a refractive index substantially equal to that of the block member. The block member is formed by alternately laminating a plurality of plate-like members whose surfaces are mirror-polished via a soft adhesive layer having flexibility, and are optically coupled. It is characterized by.
[0013]
The prism according to the present invention configured as described above suppresses astigmatism in the imaging optical system by sandwiching the diffraction grid between a pair of block members, and makes the incident light excellent in a wide incident angle range. Maintains polarization separation characteristics and can transmit or reflect depending on the polarization component Furthermore, since a pair of block members are optically coupled by laminating a plurality of plate-like members alternately via a soft adhesive layer, it is possible to reduce the stress generated inside, thereby refraction. It can transmit light without disturbing the polarization state by keeping the rate distribution uniform, and reduce optical distortion. it can.
[0014]
Further, the projection device according to the present invention transmits or reflects a light source that emits illumination light, a condenser lens that collects illumination light emitted from the light source, and light from the condenser lens according to a polarization component. A prism, a light modulation element that modulates and reflects the illumination light transmitted or reflected by the prism, and a projection lens that magnifies and projects the reflected light modulated by the light modulation element reflected or transmitted by the prism. A substantially grid-like diffraction grid formed of metal, a pair of diffraction grid base materials sandwiching the diffraction grid, an adhesive layer provided on each side facing the diffraction grid of the pair of diffraction grid base materials, and adhesion A pair of block members respectively fixed to the pair of diffraction grid bases via the layers, and the block portion in the gap formed by the diffraction grid and the pair of diffraction grid bases Medium is filled with a refractive index substantially equal to The block member is formed by alternately laminating a plurality of plate-like members whose surfaces are mirror-polished through a soft adhesive layer having flexibility, and are optically coupled. It is characterized by that.
[0015]
The projector according to the present invention configured as described above, when the reflected light modulated by the light modulation element is transmitted or reflected through the prism, the reflected light is well polarized and generated with astigmatism. The image is projected by the projection lens.
[0018]
Furthermore, the prism according to the present invention is provided on a plate-like substrate, and is provided with a light separation layer having a property of transmitting or reflecting light according to a polarization component, and a light separation layer of the plate-like substrate. A block having a pair of adhesive layers provided on the main surface side that does not come into contact with the plate-like base material of the light separation layer and a pair of block members that sandwich the light separation layer via the adhesive layer The member is composed of a plurality of plate-like members whose surfaces are mirror-polished. Stacked alternately via soft adhesive layers with softness and optically coupled It is characterized by that.
[0019]
The prism according to the present invention configured as described above, plural Through the soft adhesive layer where the plate-like member has flexibility Alternatingly stacked, optically coupled Astigmatism is suppressed by sandwiching the light separation layer using the block member, and the incident light is transmitted or reflected according to the polarization component, and is emitted without disturbing the polarization state.
[0020]
Furthermore, the projection device according to the present invention transmits or reflects the light source that emits illumination light, the condensing lens that condenses the illumination light emitted from the light source, and the light from the condensing lens according to the polarization component. A prism, a light modulation element that modulates and reflects the illumination light transmitted or reflected by the prism, and a projection lens that magnifies and projects the reflected light modulated by the light modulation element reflected or transmitted by the prism. A light separation layer provided on the plate-like substrate and having a property of transmitting or reflecting light according to the polarization component; and a main surface side where the light separation layer of the plate-like substrate is not provided and the light separation layer And a pair of block members sandwiching the light separation layer via the adhesive layer, the block member having a mirror-polished surface A plurality of plate-shaped members Stacked alternately via soft adhesive layers with softness and optically coupled It is characterized by that.
[0021]
The projector according to the present invention configured as described above, when the reflected light modulated by the light modulation element is transmitted or reflected through the prism, the reflected light is well polarized and generated with astigmatism. The image is projected by the projection lens.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a projector device to which the present invention is applied will be described with reference to the drawings.
[0023]
As shown in FIG. 1, a projector device 10 to which the present invention is applied includes a lamp 11 serving as a light source that emits illumination light, a main condenser 12, a field lens 13, and a pre-polarized light in order of the optical path from the lamp 11 side. A plate 14, a diffraction prism 15, a reflective liquid crystal panel 16, and a projection lens 17 are provided.
[0024]
The lamp 11 includes a light emitter 11a that emits white light, and a reflector 11b that reflects light emitted from the light emitter 11a. As the light emitter 11a of the lamp 11, for example, a high-pressure mercury lamp, a halogen lamp, a metal halide lamp, a xenon lamp, or the like is used. A concave mirror is used as the reflector 11b of the lamp 11, and it is preferable that the mirror surface has a shape with good circumferential efficiency, for example, a shape of a rotationally symmetric surface such as a rotating surface or a rotating ellipsoid. Yes.
[0025]
The main capacitor 12 is composed of a convex lens that collects the illumination light emitted from the lamp 11.
[0026]
The field lens 13 is configured by a convex lens, and collects the illumination light transmitted through the main capacitor 12, and is arranged so that a light beam by the illumination light is modulated by the reflective liquid crystal panel 16 and output through the projection lens 17. Has been.
[0027]
The pre-polarizing plate 14 is a polarizing plate that transmits illumination light transmitted through the field lens 13 only with a predetermined polarization component. For example, the pre-polarization plate 14 transmits an S-polarized component.
[0028]
The diffraction prism 15 is configured to transmit or reflect the illumination light in accordance with the polarization component of the illumination light transmitted through the pre-polarizing plate 14 and to separate the illumination light. For example, the diffraction prism 15 transmits P-polarized light and reflects S-polarized light by the reflecting surface 15a inclined by 45 ° with respect to the optical path to change the traveling direction by 90 °.
[0029]
In the diffraction prism 15, the illumination light transmitted through the pre-polarizing plate 14 is separated into light that travels straight through the diffraction prism 15 and light that reflects by the reflecting surface 15 a and changes in traveling direction by 90 °.
[0030]
In addition, the projector device 10 includes a reflective liquid crystal panel 16 in the traveling direction of the illumination light reflected by the reflecting surface 15 a of the diffraction prism 15.
[0031]
The reflective liquid crystal panel 16 receives a video signal, displays a pattern based on the video signal, and modulates and reflects the irradiation light when illumination light is incident thereon. The reflective liquid crystal panel 16 is a liquid crystal panel in which liquid crystal molecules are sealed, and can modulate light for each pixel.
[0032]
In the diffraction prism 15, the reflected light modulated by the reflective liquid crystal panel 16 passes through the reflecting surface 15a and travels straight.
[0033]
Further, the projector device 10 includes a projection lens 17 in the traveling direction of the reflected light modulated by the reflective liquid crystal panel 16 that has passed through the reflecting surface 15 a of the diffraction prism 15.
[0034]
The projection lens 17 is a convex lens capable of enlarging and projecting the reflected light modulated by the reflective liquid crystal panel 16 transmitted through the reflecting surface 15a of the diffraction prism 15, and projects an image on a screen or the like (not shown). Have been able to.
[0035]
Here, the configuration of the above-described diffraction prism 15 will be described.
[0036]
As shown in FIG. 2, the diffractive prism 15 diffracts incident light, a pair of diffractive grid base materials 22 sandwiching the diffractive grid 21, and the diffractive grid base 22 facing the diffractive grid 21. And a pair of prism base materials 24 bonded to each other through the adhesive layer 23.
[0037]
The diffraction grid 21 is formed of a metal in a substantially grid shape between a pair of diffraction grid base materials 22. The diffraction grid 21 is made of, for example, aluminum. The diffraction grid 21 is not limited to aluminum, and other materials may be used depending on the optical system.
[0038]
The diffraction grid base material 22 is a thin flat plate such as glass, for example, and sandwiches the diffraction grid 21.
[0039]
The adhesive layer 23 is formed of a soft adhesive having flexibility, and for example, a UV adhesive having rubber properties, a silicon adhesive having rubber properties, or the like is used. Further, the adhesive layer 23 is provided on the surface side of the diffraction grid base material 22 that faces the diffraction grid 21.
[0040]
The prism base 24 is a so-called corner prism made of a glass material such as quartz having a low birefringence or SF57 manufactured by Schott, and having a substantially prismatic shape. In this embodiment, the prism base material 24 has a shape of a triangular prism with a bottom surface having a substantially right triangle shape, and is diffracted with respect to a rectangular side surface with a short side intersecting at a substantially right angle at the bottom surface of the prism base material 24. The grid base material 22 is disposed so as to be inclined along a side surface having a long side as a ridge.
[0041]
A gap between the diffraction grid 21 and the diffraction grid base material 22 is filled with a diffraction grid medium 25 that optically couples the diffraction grid 21 and the diffraction grid base material 22. Note that when the gap between the diffraction grid 21 and the diffraction grid base material 22 is not filled with the diffraction grid medium 25, this gap becomes an air gap, which is caused by a difference in refractive index at the interface between the air and the diffraction grid base material 22. Reflection occurs and the separation characteristics deteriorate significantly.
[0042]
Here, the diffractive grid base material 22 and the diffractive grid medium 25 are designed and created with a refractive index substantially the same as that of the prism base material 24, and the interface between the prism base material 24 and the diffractive grid base material 22 is the adhesive layer 23. Are optically coupled. That is, the pitch and height of the diffraction grid 21 formed of metal are set so as to obtain a predetermined polarization separation characteristic in accordance with the diffraction grid base material 22 made of the diffraction grid medium 25, glass, or the like. A diffraction grid 21 is created that is coupled to each other.
[0043]
In such a diffractive prism 15, when non-polarized light is incident, all the interfaces are optically coupled as described above, so that they reach the diffractive grid 21 without being internally reflected. The S-polarized light is reflected by the reflecting surface 15a under the influence of diffraction, and the P-polarized light is transmitted through the reflecting surface 15a, so that the P-polarized light and the S-polarized light are well separated.
[0044]
As described above, the diffraction prism 15 is formed by the diffraction grid 21 and the diffraction grid base material 22, and has a configuration in which the diffraction grid PBS excellent in separation characteristics at a wide incident angle is sandwiched by the prism base material 24 via the adhesive layer 23. Therefore, it has excellent separation characteristics at a wide incident angle and can suppress astigmatism even when used in an imaging optical system.
[0045]
Further, since the diffraction prism 15 has a high degree of freedom in combining the constituent materials of the diffraction grid base material 22, the diffraction grid medium 25, the prism base material 24, etc., and easily obtains desired characteristics, it can be used in various optical systems. It can be used easily.
[0046]
Further, since the diffraction prism 15 has excellent separation characteristics at a wide incident angle, a desired characteristic can be obtained even when a high-grade glass material, that is, a base material having a refractive index not so high is used. Comparable performance can be obtained at low cost as compared with PBS using a multilayer film. Further, since the glass material having a high refractive index has a high specific gravity, the diffraction prism 15 can generally be reduced in weight by reducing the refractive index as much as possible.
[0047]
Furthermore, since the diffraction prism 15 is provided with a soft adhesive layer 23 between the diffraction grid base material 22 and the prism base material 24, the stress generated in the diffraction prism 15 can be moderated, and the optical Distortion can be reduced.
[0048]
Here, the operation of each part of the projector device 10 configured as described above will be described along the optical path of the illumination light emitted from the lamp 11.
[0049]
The illumination light emitted from the lamp 11 enters the main capacitor 12 as non-polarized light.
[0050]
Next, the illumination light incident on the main condenser 12 is condensed by the main condenser 12 and guided to the field lens 13, condensed by the field lens 13 and guided to the pre-polarizing plate 14.
[0051]
Next, the illumination light guided to the pre-polarizing plate 14 transmits, for example, only the S-polarized light component and is guided to the diffraction prism 15.
[0052]
Next, the illumination light guided to the diffractive prism 15 is S-polarized light, and only unnecessary P-polarized light is transmitted through the reflecting surface 15a of the diffractive prism 15 and travels straight, while the S-polarized light is reflected by the reflecting surface 15a and travels. Change direction by 90 °. That is, the illumination light is reflected by the reflecting surface 15 a of the diffraction prism 15 and is guided to the reflective liquid crystal panel 16 with the traveling direction changed by 90 °.
[0053]
Next, the illumination light guided to the reflective liquid crystal panel 16 is S-polarized light, and is modulated and reflected by the reflective liquid crystal panel 16 on which a pattern based on the video signal is displayed to change the traveling direction by 180 °. At this time, P-polarized light is generated and returned to the diffraction prism 15.
[0054]
Next, the reflected light from the reflective liquid crystal panel 16 returned to the diffraction prism 15 is P-polarized light and S-polarized light that is unnecessary OFF light, and the P-polarized light is transmitted through the reflecting surface 15 a of the diffraction prism 15. Then, the light is guided to the projection lens 17, and the S-polarized light is reflected by the reflecting surface 15a, changes the traveling direction by 90 °, and is returned to the lamp 11 side.
[0055]
As described above, the illumination light emitted from the lamp 11 is guided to the reflective liquid crystal panel 16 by the diffraction prism 15 and is modulated and reflected by the reflective liquid crystal panel 16. Then, the reflected light modulated by the reflective liquid crystal panel 16 is guided to the projection lens 17 and is enlarged and projected on the screen or the like by the projection lens 17.
[0056]
As described above, the projector device 10 uses the diffraction prism 15 having the diffraction grid 21, thereby reducing the dependency of the polarization separation characteristic on the incident angle of light and maintaining the separation characteristic at a high NA. Therefore, it is possible to project an image with good contrast, improve the light utilization efficiency, and project a bright image.
[0057]
Further, the projector device 10 can suppress astigmatism generated in the imaging optical system by using only the conventional flat diffraction grating PBS by using the diffraction prism 15, so that a clear image can be obtained. Can be projected.
[0058]
Furthermore, since the diffraction prism 15 can be produced at low cost and light weight as described above, the projector device 10 can reduce the cost and weight of the entire device.
[0059]
Furthermore, since the diffraction prism 15 can reduce optical distortion, the projector device 10 can suppress black unevenness in the projected image.
[0060]
Next, as another projector apparatus to which the present invention is applied, a projector apparatus 30 shown in FIG. 3 will be described.
[0061]
The projector device 30 includes a lamp 31 serving as a light source that emits illumination light, and a main capacitor 32, a field lens 33, a pre-polarizing plate 34, and a diffraction prism 35 in order of the optical path from the lamp 31 side.
[0062]
The lamp 31 can emit white light. Such a lamp 31 includes a light emitter 31a that emits white light, and a reflector 31b that reflects light emitted from the light emitter 31a. As the light emitter 31a of the lamp 31, for example, a high pressure mercury lamp, a halogen lamp, a metal halide lamp, a xenon lamp, or the like is used. As the reflector 31b of the lamp 31, a concave mirror is used, and it is preferable that the mirror surface has a shape with good circumferential efficiency, for example, a shape of a rotationally symmetric surface such as a rotating surface or a rotating ellipsoid. Yes.
[0063]
The main capacitor 32 is a convex lens that collects the illumination light emitted from the lamp 31.
[0064]
The field lens 33 is a convex lens that collects the illumination light transmitted through the main condenser 32.
[0065]
The pre-polarizing plate 34 is a polarizing element that transmits only a predetermined polarization component of the illumination light transmitted through the field lens 33. For example, the pre-polarizing plate 34 transmits an S-polarized component. PBS may be used as this polarizing element.
[0066]
The diffraction prism 35 is configured to transmit or reflect the illumination light according to the polarization component of the illumination light transmitted through the pre-polarizing plate 34 and separate it. For example, the diffraction prism 35 transmits P-polarized light and reflects S-polarized light by the reflecting surface 35a inclined by 45 ° with respect to the optical path to change the traveling direction by 90 °.
[0067]
In the diffraction prism 35, the illumination light transmitted through the pre-polarizing plate 34 is separated into light that travels straight through the diffraction prism 35 and light that is reflected by the reflecting surface 35a and whose traveling direction changes by 90 °.
[0068]
In addition, the projector device 30 includes a reflective liquid crystal panel 36 in the traveling direction of the illumination light reflected by the reflecting surface 35 a of the diffraction prism 35.
[0069]
The reflective liquid crystal panel 36 receives a video signal, displays a pattern based on the video signal, and modulates and reflects the irradiation light when illumination light is incident thereon. The reflective liquid crystal panel 36 is a liquid crystal panel in which liquid crystal molecules are sealed, and can modulate light for each pixel.
[0070]
In the diffraction prism 35, the reflected light modulated by the reflective liquid crystal panel 36 passes through the reflecting surface 35a and travels straight.
[0071]
Further, the projector device 30 includes a projection lens 37 in the traveling direction of the reflected light modulated by the reflective liquid crystal panel 36 that has passed through the reflecting surface 35 a of the diffraction prism 35.
[0072]
The projection lens 37 is a convex lens that is capable of enlarging and projecting the reflected light modulated by the reflective liquid crystal panel 36 that has passed through the reflective surface 35a of the diffraction prism 35, and projects an image on a screen (not shown). Have been able to.
[0073]
By the way, the optical member such as the diffraction prism 35 as described above is subjected to stress due to heating by light from the light source, external holding force or adhesive force when fixing or bonding to the apparatus, and the like, and optical distortion is caused. appear.
[0074]
Therefore, as shown in FIG. 4, such a problem can be solved by dividing the optical member 40 into a plurality of flat plate members 41 and laminating them through the soft adhesive layer 42.
[0075]
That is, the optical member 40 includes a plurality of flat plate members 41 and a soft adhesive layer 42 having a softness to bond them. The flat plate member 41 is a member whose surface is mirror-polished and is made of a material substantially equivalent to the optical member 40. The soft adhesive layer 42 is formed of a soft soft adhesive, and for example, a rubbery UV adhesive, a rubbery silicon adhesive, or the like is used.
[0076]
The optical member 40 configured as described above has an interface between the flat plate member 41 and the soft adhesive layer 42 that is optically coupled, and functions as one member.
[0077]
Further, the optical member 40 divides the constituent members into a plurality of flat plate members 41 and inserts a soft adhesive layer 42 at the interface thereof, so that the stress applied in the interface direction is released by the soft adhesive layer 42 and is optically Generation of a large distortion can be suppressed. That is, the optical elastic constant of the entire optical member 40 can be reduced. In other words, the optical member 40 having a low optical elastic constant can be created by dividing the member having a high optical elastic constant into the plurality of flat plate members 41 as described above.
[0078]
As described above, in order to release the stress of a predetermined optical member, the optical member is divided into a plurality of flat plates, and the interface between these flat plates is optically bonded with a soft adhesive, and applied in the interface direction. The stress can be released by the adhesive, and the generation of optical distortion can be suppressed. Therefore, even if the incident light passes through the optical component and is separated by a polarization separation layer or the like and becomes light of a predetermined polarization state such as S-polarized light or P-polarized light, it is polarized light due to optical distortion. The light can be transmitted and emitted without causing a disturbance in direction.
[0079]
Further, for example, when an optical member having a shape such as a triangular prism or a pyramid is divided into a plurality of flat plate members whose cross-sectional shape gradually changes, and the flat plate member is configured by laminating via a soft adhesive, that is, When the shape of two laminated surfaces where each flat plate member is laminated via a soft adhesive is different and the laminated surface has the same shape as the laminated surface of another adjacent flat plate member, It is preferable because stress due to temperature changes of different flat plate members is absorbed by the adhesive having flexibility.
[0080]
Therefore, the above-described method is used for the diffraction prism 35 in the projector device 30 described above.
[0081]
Here, the configuration of the above-described diffraction prism 35 will be described.
[0082]
As shown in FIG. 5, the diffraction prism 35 is bonded to the diffraction grid 51, a pair of diffraction grid base materials 52 that sandwich the diffraction grid 51, and the surface of the diffraction grid base material 52 that faces the diffraction grid 51. And a pair of prism base materials 54 joined via a layer 53.
[0083]
The diffraction grid 51 is formed of a metal in a substantially grid shape between the pair of diffraction grid bases 52. The diffraction grid 51 is made of, for example, aluminum. The diffraction grid 51 is not limited to aluminum, and other materials can be used depending on the optical system.
[0084]
The diffraction grid base material 52 is a thin flat plate such as glass, for example, and sandwiches the diffraction grid 51.
[0085]
The adhesive layer 53 is formed of a soft adhesive having softness, and for example, a UV adhesive having rubber properties, a silicon adhesive having rubber properties, or the like is used. The adhesive layer 53 is provided on the surface of the diffraction grid base material 52 that faces the diffraction grid 51.
[0086]
The prism base 54 is a so-called corner prism having a substantially prismatic shape.
[0087]
The prism base 54 is configured such that a plurality of flat plate members 55 whose surfaces are mirror-polished are joined via a soft adhesive layer 56, and each flat plate member 55 is optically connected via the soft adhesive layer 56. Is bound to.
[0088]
The soft adhesive layer 56 is formed of a soft adhesive having softness, and for example, a UV adhesive having rubber properties, a silicon adhesive having rubber properties, or the like is used.
[0089]
In this embodiment, a triangular prism-shaped prism base material 54 whose bottom surface is a substantially right triangle is divided into a plurality of flat plate members 55 having a square cross section. In this case, at least one flat plate member 55 is different in the shape of two laminated surfaces laminated via the soft adhesive layer 56, and the laminated surface is equal in shape to the laminated surface of other adjacent flat plate members 55. ing. A plurality of flat plate members 55 having different shapes are stacked to constitute a triangular prism-shaped prism base material 54 as a whole. The prism base material 54 configured in this manner functions as a single prism because the flat plate member 55 and the soft adhesive layer 56 are optically coupled to each other.
[0090]
Further, since the plurality of flat plate members 55 constituting the prism base material 54 are arranged in a direction in which the adhesive layer 53 and the soft adhesive layer 56 of the diffraction grid base material 52 are parallel, the diffraction grid base material 52 and the flat plate member. 55 can be satisfactorily optically coupled via the adhesive layer 53 with their planes facing each other.
[0091]
A gap between the diffraction grid 51 and the diffraction grid base material 52 is filled with a diffraction grid medium 57. When the gap between the diffraction grid 51 and the diffraction grid base material 52 is not filled with the diffraction grid medium 57, the gap becomes an air gap, which is caused by a difference in refractive index at the interface between the air and the diffraction grid base material 52. Reflection occurs and the separation characteristics are significantly deteriorated.
[0092]
Here, the diffractive grid base material 52 and the diffractive grid medium 57 are designed and created with a refractive index substantially the same as that of the prism base material 54, and the interface between the prism base material 54 and the diffractive grid base material 52 is an adhesive layer. 53 is optically coupled.
[0093]
In such a diffractive prism 35, when non-polarized light is incident, all the interfaces are optically coupled as described above, so that they reach the diffractive grid 51 without being internally reflected. The S-polarized light is reflected by the reflecting surface 35a under the influence of diffraction, and the P-polarized light is transmitted through the reflecting surface 35a, so that the P-polarized light and the S-polarized light are separated.
[0094]
Such a diffractive prism 35 is formed by a diffractive grid 51 and a diffractive grid base material 52, and is configured to sandwich a diffractive grid PBS excellent in separation characteristics at a wide incident angle by a prism base material 54 via an adhesive layer 53. Therefore, it has excellent separation characteristics at a wide incident angle and can suppress astigmatism even when used in an imaging optical system.
[0095]
Further, since the diffraction prism 35 is excellent in separation characteristics at a wide incident angle, a desired characteristic can be obtained even when a high-grade glass material, that is, a base material having a refractive index not so high is used. Comparable performance can be obtained at low cost as compared with PBS using a multilayer film. Further, since a glass material having a high refractive index has a high specific gravity, the diffraction prism 35 can generally be reduced in weight by reducing the refractive index as much as possible.
[0096]
Furthermore, since the diffraction prism 35 has a high degree of freedom in combining the materials of the respective constituent elements and easily obtains desired characteristics, it can be easily used in various optical systems.
[0097]
Furthermore, since the diffraction prism 35 is provided with the adhesive layer 53 having flexibility between the diffraction grid base material 52 and the prism base material 54, the stress generated in the diffraction prism 35 can be reduced. Distortion can be reduced.
[0098]
Furthermore, since the prism base 54 is provided with the soft adhesive layer 56 between the plurality of flat plate members 55, the diffraction prism 35 can further reduce the stress generated in the diffraction prism 35, and optically. Distortion can be reduced.
[0099]
Here, regarding the projector device 30 configured as described above, the operation of each unit will be described along the optical path of the illumination light emitted from the lamp 31.
[0100]
The illumination light emitted from the lamp 31 enters the main capacitor 32 as non-polarized light.
[0101]
Next, the illumination light incident on the main condenser 32 is condensed by the main condenser 32 and guided to the field lens 33, condensed by the field lens 33 and guided to the pre-polarizing plate 34.
[0102]
Next, the illumination light guided to the pre-polarizing plate 34 is transmitted only to the S-polarized light component and guided to the diffraction prism 35, for example.
[0103]
Next, the illumination light guided to the diffractive prism 35 is S-polarized light, and only unnecessary P-polarized light is transmitted through the reflecting surface 35a of the diffractive prism 35 and travels straight, while the S-polarized light is reflected by the reflecting surface 35a and travels. Change direction by 90 °. That is, the illumination light is reflected by the reflecting surface 35 a of the diffraction prism 35 and is guided to the reflective liquid crystal panel 36 with the traveling direction changed by 90 °.
[0104]
Next, the illumination light guided to the reflective liquid crystal panel 36 is S-polarized light, and is modulated and reflected by the reflective liquid crystal panel 36 on which a pattern based on the video signal is displayed to change the traveling direction by 180 °. At this time, P-polarized light is generated and returned to the diffraction prism 35.
[0105]
Next, the reflected light from the reflective liquid crystal panel 36 returned to the diffraction prism 35 is P-polarized light and S-polarized light that is unnecessary OFF light, and the P-polarized light is transmitted through the reflection surface 35 a of the diffraction prism 35. Then, the light is guided to the projection lens 17, and the S-polarized light is reflected by the reflecting surface 35a, changes the traveling direction by 90 °, and is returned to the lamp 31 side.
[0106]
As described above, the illumination light emitted from the lamp 31 is guided to the reflective liquid crystal panel 36 by the diffraction prism 35 and is modulated and reflected by the reflective liquid crystal panel 36. Then, the reflected light modulated by the reflective liquid crystal panel 36 is guided to the projection lens 37, and is enlarged and projected on the screen or the like by the projection lens 37.
[0107]
As described above, the projector device 30 can maintain a separation characteristic at a high NA by using the diffraction prism 35 having the diffraction grid 51, and therefore can project an image with good contrast, Utilization efficiency is improved and bright images can be projected.
[0108]
Further, the projector device 30 can suppress astigmatism that occurs in the imaging optical system by using only the conventional flat diffraction grid PBS by using the diffraction prism 35, so that a clear image can be obtained. Can be projected.
[0109]
Furthermore, as described above, since the diffraction prism 35 can be produced at a low cost in the projector device 30, the cost of the entire device can be reduced.
[0110]
Furthermore, since the diffraction prism 35 can reduce optical distortion, the projector device 30 can suppress black unevenness in the projected image.
[0111]
Furthermore, since the projector device 30 can reduce the weight of the diffraction prism 35, the entire device can be reduced in weight.
[0112]
Furthermore, since the diffraction prism 35 can suppress distortion due to thermal stress, the projector device 30 can reduce the influence of heat generation caused by increasing the amount of input light, thereby improving the brightness of the projected image. Can be made.
[0113]
Note that the diffraction prism 35 described above may have a configuration in which the stacking directions of the flat plate members 55 of the prism base material 54 are different as shown in FIG. The lamination direction of the flat plate member 55 is not limited to the direction shown in FIGS. 5 and 6, and may be an optimum direction depending on the optical system used.
[0114]
The present invention can also be used for a projector apparatus that can project a color image using a plurality of the diffraction prisms 15 and / or diffraction prisms 35 described above.
[0115]
First, a projector device 60 shown in FIG. 7 will be described as a projector device capable of projecting a color image to which the present invention is applied.
[0116]
The projector device 60 includes a lamp 61 serving as a light source that emits illumination light, a fly-eye integrator 62, a PS conversion composition element 63, a main capacitor 64, a field lens 65, and a pre-polarized light in order of the light path from the lamp 61 side. A plate 66, a first G polarization rotation element 67, and an incident PBS 68 are provided.
[0117]
The lamp 61 can emit white light including light in the wavelength bands of red, green, and blue, which are the three primary colors of light, necessary for displaying a color image. Such a lamp 61 includes a light emitter 61a that emits white light, and a reflector 61b that reflects light emitted from the light emitter 61a. As the light emitter 61a of the lamp 61, for example, a high-pressure mercury lamp, a halogen lamp, a metal halide lamp, a xenon lamp, or the like is used. As the reflector 61b of the lamp 61, a concave mirror is used, and it is preferable that the mirror surface has a shape with good circumferential efficiency, for example, a shape of a rotationally symmetric surface such as a rotating surface or a rotating ellipsoid. Yes.
[0118]
The fly eye integrator 62 uniformizes the illuminance distribution by using the illumination light as a light beam having the effective area of the liquid crystal panel so that the illumination light emitted from the lamp 61 uniformly illuminates the effective area of the liquid crystal panel, which will be described later. Have been to. Such a fly eye integrator 62 is also referred to as a multi-lens array, and a combination of two small convex lenses provided in an array form, and the illumination light from the lamp 61 is collected by the multi-lens array 62a on the lamp 61 side. A small point light source is created, and the illumination light from each point light source is synthesized by the other multi-lens array 62b.
[0119]
The PS conversion composition element 63 is configured to align the polarization components of the illumination light in order to effectively use the illumination light from the lamp 61. The PS conversion / combination element 63 is composed of a λ / 2 plate, a polarizing beam splitter, or the like, and is configured to convert P-polarized light into S-polarized light, for example, and transmits S-polarized light in incident illumination light. In addition, since the P-polarized light is converted to S-polarized light and output, all the illumination light can be converted to S-polarized light.
[0120]
The main capacitor 64 is a convex lens that condenses the illumination light transmitted through the PS conversion composition element 63.
[0121]
The field lens 65 is a convex lens that collects the illumination light transmitted through the main condenser 64.
[0122]
The pre-polarizing plate 66 is a polarizing plate that transmits the illumination light transmitted through the field lens 65 only with a predetermined polarization component. For example, the pre-polarization plate 66 transmits an S-polarized component.
[0123]
The first G polarization rotation element 67 rotates the green wavelength band, that is, the polarization plane of the green component of the illumination light collected by the field lens 65 by 90 °, and the other wavelength band, that is, red. And a laminated retardation film optimized to transmit while maintaining the polarization state of the blue component.
[0124]
The incident PBS 68 is configured to transmit or reflect the illumination light according to the polarization component of the illumination light that has passed through the first G polarization rotation element 67 and separate it. The incident PBS 68 has substantially the same configuration as the diffraction prism 15 or the diffraction prism 35 described above. For example, the incident PBS 68 transmits the P-polarized light and reflects the S-polarized light by the reflecting surface 68a inclined by 45 ° with respect to the optical path. Change direction by 90 °.
[0125]
In the incident PBS 68, the illumination light transmitted through the first G-polarization rotating element 67 is separated into light that travels straight through the incident PBS 68 and light that is reflected by the reflecting surface 68a and whose traveling direction changes by 90 °. .
[0126]
In addition, the projector device 60 is provided with a G-PBS 69 in the traveling direction of the illumination light transmitted through the incident PBS 68.
[0127]
The G-PBS 69 is configured to transmit or reflect the illumination light according to the polarization component of the illumination light transmitted through the reflecting surface 68a of the incident PBS 68. The G-PBS 69 has substantially the same configuration as the diffraction prism 15 or the diffraction prism 35 described above. For example, the G-PBS 69 transmits a P-polarized light and travels straight, and the S-polarized light is reflected by a reflecting surface 69a inclined by 45 ° with respect to the optical path. Reflect and change the direction of travel by 90 °.
[0128]
In the G-PBS 69, the illumination light transmitted through the incident PBS 68 is transmitted.
[0129]
Furthermore, the projector device 60 includes a first liquid crystal panel 70 in the traveling direction of the light transmitted through the G-PBS 69.
[0130]
The first liquid crystal panel 70 receives a green video signal among video signals separated for each of the three primary colors of light, displays a pattern based on the green video signal, and receives illumination light. The irradiation light is modulated and reflected. The first liquid crystal panel 70 is a display panel in which liquid crystal molecules are sealed, and can modulate light for each pixel.
[0131]
In the G-PBS 69, the reflected light modulated by the first liquid crystal panel 70 is reflected by the reflecting surface 69a to change the traveling direction by 90 °.
[0132]
Furthermore, the projector device 60 includes a first R polarization rotating element 71 and an RB-PBS 72 in the optical path order of the illumination light reflected by the reflecting surface 68a of the incident PBS 68.
[0133]
The first R polarization rotation element 71 rotates a predetermined wavelength band, that is, a polarization plane of a component of a predetermined color, of the illumination light reflected by the reflection surface 68a of the incident PBS 68 by 90 °, and other wavelength bands. The retardation film is optimized so as to transmit while maintaining the polarization state. For example, since the green component is already transmitted and separated by the incident PBS 68, the first R polarization rotation element 71 changes the polarization plane of the red illumination light out of the blue and red components reflected by the reflection surface 68a. Rotate to maintain the polarization state of the illumination light in the other wavelength band, that is, the blue illumination light, and transmit it respectively.
[0134]
The RB-PBS 72 is configured to transmit or reflect the illumination light according to the polarization component of the illumination light transmitted through the first R polarization rotation element 71 and separate it. The RB-PBS 72 has substantially the same configuration as that of the diffraction prism 15 or the diffraction prism 35 described above. For example, the RB-PBS 72 is a reflection surface 72a that transmits P-polarized light and travels straight and tilts S-polarized light by 45 ° with respect to the optical path. Reflect and change the direction of travel by 90 °.
[0135]
In the RB-PBS 72, the illumination light transmitted through the first R polarization rotating element 71 and the reflected light modulated by the liquid crystal panel described later are reflected by the light that passes through the RB-PBS 72 and travels straight on the reflection surface 72a. It is separated into light whose traveling direction changes by 90 °.
[0136]
Furthermore, the projector device 60 includes a second liquid crystal panel 73 in the traveling direction of the illumination light transmitted through the RB-PBS 72 and a third liquid crystal panel 74 in the traveling direction of the illumination light reflected by the reflecting surface 72a of the RB-PBS 72. With.
[0137]
The second liquid crystal panel 73 receives a red video signal among video signals separated for each of the three primary colors of light, displays a pattern based on the red video signal, and receives illumination light. The irradiation light is modulated and reflected. The second liquid crystal panel 73 is a liquid crystal panel in which liquid crystal molecules are sealed, and can modulate light for each pixel.
[0138]
The third liquid crystal panel 74 receives a blue video signal among video signals separated for each of the three primary colors of light, displays a pattern based on the blue video signal, and receives illumination light. The irradiation light is modulated and reflected. The third liquid crystal panel 74 is a liquid crystal panel in which liquid crystal molecules are enclosed, and can modulate light for each pixel.
[0139]
In the RB-PBS 72, the reflected light modulated by the second liquid crystal panel 73 is reflected by the reflecting surface 72a and the traveling direction changes by 90 °, and the reflected light modulated by the third liquid crystal panel 74 is changed to RB. -Go straight through PBS 72 and pass through.
[0140]
Furthermore, the projector device 60 reflects the reflected light modulated by the second liquid crystal panel 73 reflected by the reflecting surface 72a of the RB-PBS 72 and the reflected light modulated by the third liquid crystal panel 74 transmitted through the RB-PBS 72a. The second R polarization rotation element 75 is provided in the order of the optical paths.
[0141]
The second R polarization rotation element 75 is modulated by the reflected light modulated by the second liquid crystal panel 73 reflected by the reflection surface 72 a of the RB-PBS 72 and the third liquid crystal panel 74 transmitted by the RB-PBS 72. A phase difference film optimized to transmit a predetermined wavelength band, that is, a polarization plane of a predetermined color component of reflected light by 90 ° while maintaining the polarization state of the other wavelength band. It is. For example, since the green component is already transmitted and separated by the incident PBS 68, the second R polarization rotation element 75 rotates the plane of polarization by 90 ° by the red light of the transmitted blue and red components, and so on. The polarization state of light in the wavelength band, that is, blue light is maintained and transmitted.
[0142]
Furthermore, the projector device 60 transmits the second liquid crystal transmitted through the second R-polarization rotating element 75 in the traveling direction of the reflected light modulated by the first liquid crystal panel 70 reflected by the reflective surface 69a of the G-PBS 69. An outgoing PBS 76 is provided in the traveling direction of the reflected light modulated by the panel 73 and the reflected light modulated by the third liquid crystal panel 74.
[0143]
The outgoing PBS 76 is the reflected light modulated by the first liquid crystal panel 70 reflected by the reflecting surface 69 a of the G-PBS 69 and the reflected light modulated by the second liquid crystal panel 73 that has passed through the second R polarization rotating element 75. The light and the reflected light modulated by the third liquid crystal panel 74 are transmitted or reflected according to the polarization component to be combined. The outgoing PBS 76 has substantially the same configuration as the diffraction prism 15 or the diffraction prism 35 described above. For example, the outgoing PBS 76 transmits P-polarized light and reflects S-polarized light by a reflection surface 76a inclined by 45 ° with respect to the optical path. Change direction by 90 °.
[0144]
In the outgoing PBS 76, the reflected light modulated by the first liquid crystal panel 70 reflected by the reflective surface 69 a of the G-PBS 69 is reflected by the reflective surface 76 a and transmitted through the second R polarization rotating element 75. The reflected light modulated by 73 and the reflected light modulated by the third liquid crystal panel 74 are transmitted and traveled straight and output in the same direction.
[0145]
Furthermore, the projector device 60 includes reflected light modulated by the first liquid crystal panel 70 reflected by the reflecting surface 76a of the outgoing PBS 76, reflected light modulated by the second liquid crystal panel 73 that has passed through the outgoing PBS 76, and A second G polarization rotation element 77, an output polarizing plate 78, and a projection lens 79 are provided in the order of the optical path in the traveling direction with the reflected light modulated by the third liquid crystal panel 74.
[0146]
The second G polarization rotation element 77 is reflected light that is modulated by the first liquid crystal panel 70 reflected by the reflecting surface 76 a of the outgoing PBS 76, and reflected light that is modulated by the second liquid crystal panel 73 that has passed through the outgoing PBS 76. And the reflected light modulated by the third liquid crystal panel 74, the polarization plane of the green wavelength band, that is, the green component is rotated by 90 °, and the other wavelength bands, that is, red and blue components It is a laminate type retardation film optimized so as to transmit while maintaining the polarization state.
[0147]
The output polarizing plate 78 is a reflected light modulated by the first liquid crystal panel 70, a reflected light modulated by the second liquid crystal panel 73, and a third liquid crystal that has been transmitted through the second G polarization rotating element 77. The polarizing plate transmits only a predetermined polarization component of the reflected light modulated by the panel 74. For example, a P-polarized component is transmitted.
[0148]
The projection lens 79 is reflected by the first liquid crystal panel 70, the reflected light modulated by the second liquid crystal panel 73, and the third liquid crystal panel 74 that is transmitted through the output polarizing plate 78. The convex lens can project the reflected light together and can project an image on a screen or the like (not shown).
[0149]
Regarding the projector device 60 configured as described above, the operation of each unit will be described along the optical path of the illumination light emitted from the lamp 61.
[0150]
The illumination light emitted from the lamp 61 includes red, green, and blue wavelength bands that are the three primary colors of light, and is guided to the fly-eye integrator 62 as non-polarized light.
[0151]
Next, the illumination light guided to the fly eye integrator 62 is transmitted with the illuminance distribution made uniform by the fly eye integrator 62, and is incident on the PS conversion composition element 63.
[0152]
Next, the illumination light incident on the PS conversion / combination element 63 transmits the S-polarized light as it is, and the P-polarized light is converted into the S-polarized light, and all enters the main capacitor 64 as the S-polarized light.
[0153]
Next, the illumination light incident on the main condenser 64 is condensed by the main condenser 64 and guided to the field lens 65, and is condensed by the field lens 65 and incident on the pre-polarizing plate 66.
[0154]
Next, the illumination light incident on the pre-polarizing plate 66 is guided to the first G polarization rotation element 67 as S-polarized light with the polarization components further aligned.
[0155]
Next, the illumination light incident on the first G-polarization rotating element 67 is rotated by 90 ° in the green wavelength band so that the polarization plane is turned into P-polarized light, is transmitted to the incident PBS 68, and has red and blue wavelengths. The band component is transmitted as S-polarized light and guided to the incident PBS 68.
[0156]
Next, the illumination light guided to the incident PBS 68 is P-polarized light in the green wavelength band and S-polarized light in the red and blue wavelength bands. Only the P-polarized light is transmitted through the reflecting surface 68a of the incident PBS 68 and travels straight. At the same time, the S-polarized light is reflected by the reflecting surface 68a to change the traveling direction by 90 °. That is, the illumination light in the green wavelength band passes through the incident PBS 68 and travels straight and is guided to the G-PBS 69, and the illumination light in the red and blue wavelength bands is reflected by the reflecting surface 68a of the incident PBS 68 and travels. The direction is changed by 90 ° and guided to the first R polarization rotation element 71.
[0157]
Here, among the illumination lights separated by the incident PBS 68 described above, the optical path of the illumination light in the green wavelength band that is transmitted through the incident PBS 68 and guided to the G-PBS 69 will be described.
[0158]
Next, the illumination light guided to the G-PBS 69 is P-polarized light in the green wavelength band, passes through the G-PBS 69, travels straight, and is guided to the first liquid crystal panel 70.
[0159]
The illumination light guided to the first liquid crystal panel 70 is P-polarized light in the green wavelength band, and is modulated and reflected by the first liquid crystal panel 70 on which a pattern based on the green video signal is displayed. At this time, S-polarized light is generated and returned to the G-PBS 69.
[0160]
Next, the reflected light from the first liquid crystal panel 70 returned to the G-PBS 69 is S-polarized light in the green wavelength band and P-polarized light that is unnecessary OFF light, and the S-polarized light is reflected by the reflective surface 69a. Then, the traveling direction is changed by 90 ° and guided to the outgoing PBS 76, and the P-polarized light is transmitted through the reflecting surface 69a and returned to the lamp 61 side.
[0161]
Next, the reflected light from the first liquid crystal panel 70 guided to the outgoing PBS 76 is S-polarized light in the green wavelength band, is reflected by the reflecting surface 76a of the outgoing PBS 76, changes the traveling direction by 90 °, and is second. To the polarization rotation element 77.
[0162]
Next, the reflected light from the first liquid crystal panel 70 guided to the second G polarization rotation element 77 is S polarization in the green wavelength band, and the second G polarization rotation element 77 causes the green wavelength band to be reflected. Is rotated by 90 ° to become P-polarized light, which is guided to the output polarizing plate 78.
[0163]
Next, the reflected light from the first liquid crystal panel 70 guided to the output polarizing plate 78 is P-polarized light in the green wavelength band, and the polarization component is aligned with the P-polarized light by the output polarizing plate 78 and transmitted and projected. Guided to lens 79.
[0164]
On the other hand, of the illumination light separated by the incident PBS 68 described above, the optical path of the illumination light in the red and blue wavelength bands, which is reflected by the reflecting surface 68a of the incident PBS 68 and whose traveling direction is changed by 90 degrees, will be described.
[0165]
The illumination light guided to the first R polarization rotating element 71 is S-polarized light in the red and blue wavelength bands, and only the polarization plane in the red wavelength band is rotated by 90 ° by the first R polarization rotating element 71. P-polarized light is guided to the RB-PBS 72.
[0166]
Next, the illumination light guided to the RB-PBS 72 is P-polarized light in the red wavelength band and S-polarized light in the blue wavelength band, and the P-polarized light in the red wavelength band is transmitted through the reflecting surface 72a of the RB-PBS 72. Then, the light is guided to the second liquid crystal panel 73, and the S-polarized light in the blue wavelength band is reflected by the reflection surface 72 a of the RB-PBS 72, changes the traveling direction by 90 °, and is guided to the third liquid crystal panel 74.
[0167]
Next, the illumination light guided to the second liquid crystal panel 73 is P-polarized light in the red wavelength band, and is modulated and reflected by the second liquid crystal panel 73 on which a pattern based on the red video signal is displayed. The traveling direction is changed by 180 °, and S-polarized light is generated at this time and returned to the RB-PBS 72.
[0168]
Next, the illumination light guided to the third liquid crystal panel 74 is S-polarized light in the blue wavelength band, and is modulated and reflected by the third liquid crystal panel 74 on which a pattern based on the blue video signal is displayed. The traveling direction is changed by 180 °, and at this time, P-polarized light is generated and returned to the RB-PBS 72.
[0169]
Next, the reflected light from the second liquid crystal panel 73 returned to the RB-PBS 72 is S-polarized light in the red wavelength band and P-polarized light that is OFF light, and the P-polarized light is the reflecting surface 72a of the RB-PBS 72. And is returned to the lamp 61 side, and the S-polarized light is reflected by the reflecting surface 72a, changes the traveling direction by 90 °, and is guided to the second R-polarization rotating element 75. The reflected light from the third liquid crystal panel 74 returned to the RB-PBS 72 is P-polarized light in the blue wavelength band and S-polarized light that is OFF light, and the S-polarized light is reflected on the reflective surface 72 a of the RB-PBS 72. Reflected and returned to the lamp 61 side, the P-polarized light is transmitted through the reflecting surface 72 a of the RB-PBS 72 and guided to the second R-polarization rotating element 75.
[0170]
Next, the reflected light from the second liquid crystal panel 73 guided to the second R polarization rotation element 75 is S-polarized light in the red wavelength band, and the polarization plane is 90 by the second R polarization rotation element 75. Rotated to P-polarized light and guided to the outgoing PBS 76. The reflected light from the third liquid crystal panel 74 guided to the second R polarization rotating element 75 is P polarized light in the blue wavelength band, and is transmitted through the second R polarization rotating element 75 to be emitted. Guided to PBS 76.
[0171]
Next, the reflected light from the second liquid crystal panel 73 guided to the outgoing PBS 76 is P-polarized light in the red wavelength band, passes straight through the reflecting surface 76a of the outgoing PBS 76, and travels straight to the second G-polarization rotating element. 77. The reflected light from the third liquid crystal panel 74 guided to the outgoing PBS 76 is P-polarized light in the blue wavelength band, passes straight through the reflecting surface 76a of the outgoing PBS 76, and travels straight to the second G polarization rotating element 77. Led to.
[0172]
Next, the reflected light from the second liquid crystal panel 73 guided to the second G-polarization rotating element 77 is P-polarized light in the red wavelength band, passes through the reflecting surface 76a of the outgoing PBS 76, goes straight, and is emitted. Guided to the polarizing plate 78. The reflected light from the third liquid crystal panel 74 guided to the second G-polarization rotating element 77 is P-polarized light in the blue wavelength band, passes straight through the reflecting surface 76a of the outgoing PBS 76, and travels straight. Guided to the plate 78.
[0173]
Next, the reflected light from the second liquid crystal panel 73 guided to the output polarizing plate 78 is P-polarized light in the red wavelength band, and the polarized light component is aligned with the P-polarized light by the output polarizing plate 78 and is transmitted and projected. Guided to lens 79. The reflected light from the third liquid crystal panel 74 guided to the output polarizing plate 78 is P-polarized light in the blue wavelength band, and the polarized light component is aligned with the P-polarized light by the output polarizing plate 78 and is transmitted. 79 leads.
[0174]
As described above, the light of each wavelength band separated into the three optical paths by the incident PBS 68 and the RB-PBS 72 is incident on the liquid crystal panel corresponding to each wavelength band as illumination light and modulated by each liquid crystal panel. Reflected. Then, the reflected lights modulated by the respective liquid crystal panels are combined by the outgoing PBS 76, guided to the projection lens 79, and enlarged and projected onto the screen or the like by the projection lens 79.
[0175]
Such a projector device 60 uses the above-described diffraction prism 15 or diffraction prism 35 for the entrance PBS 68, G-PBS 69, RB-PBS 72, and exit PBS 76, respectively, and thus the projector device 10 and / or the projector device 30 described above. The same effect can be obtained.
[0176]
Next, a projector device 80 shown in FIG. 8 will be described as a projector device capable of projecting a color image to which the present invention is applied.
[0177]
The projector device 80 includes a lamp 81 serving as a light source that emits illumination light, and a fly-eye integrator 82, a PS conversion composition element 83, a main capacitor 84, and a cross dichroic mirror 85 in order of the optical path from the lamp 81 side. ing.
[0178]
The lamp 81 can emit white light including light in the wavelength bands of red, green, and blue, which are the three primary colors of light, necessary for displaying a color image. Such a lamp 81 includes a light emitter 81a that emits white light, and a reflector 81b that reflects light emitted from the light emitter 81a. As the light emitter 81a of the lamp 81, for example, a high pressure mercury lamp, a halogen lamp, a metal halide lamp, a xenon lamp or the like is used. As the reflector 81b of the lamp 81, a concave mirror is used, and it is preferable that the mirror surface has a shape with good circumferential efficiency. For example, the reflector 81b has a shape of a rotationally symmetric surface such as a rotating surface or a rotating ellipsoid. Yes.
[0179]
The fly eye integrator 82 makes the illumination light a light beam having a shape of the effective area of the liquid crystal panel so that the illumination light emitted from the lamp 81 uniformly illuminates the effective area of the liquid crystal panel, which will be described later, and uniforms the illuminance distribution. Have been to. Such a fly's eye integrator 82 is also called a multi-lens array, which combines two small convex lenses provided in an array, and collects illumination light from the lamp 81 by a multi-lens array 82a on the lamp 81 side. A small point light source is created, and the illumination light from each point light source is synthesized by the other multi-lens array 82b.
[0180]
The PS conversion composition element 83 is configured to align the polarization components of the illumination light in order to effectively use the illumination light from the lamp 81. The PS conversion / synthesizing element 83 is configured by a λ / 2 plate, a polarization beam splitter, or the like, and is configured to convert P-polarized light into S-polarized light, for example, and transmits S-polarized light in incident illumination light. In addition, since the P-polarized light is converted to S-polarized light and output, all the illumination light can be converted to S-polarized light.
[0181]
The main capacitor 84 is a convex lens that condenses the illumination light transmitted through the PS conversion composition element 83.
[0182]
The cross dichroic mirror 85 reflects the illumination light by the reflection surface 85a or the reflection surface 85b that is inclined by 45 ° with respect to the optical path and orthogonal to each other in accordance with the wavelength band of the illumination light collected by the main condenser 84. Has been. The cross dichroic mirror 85 is composed of a dielectric multilayer film or the like. For example, light in the blue wavelength band is reflected by a reflecting surface 85a inclined by 45 ° with respect to the optical path, the traveling direction is changed by 90 °, and red and red Light in the green wavelength band is reflected by the reflecting surface 85b inclined by 45 ° with respect to the optical path, and the traveling direction is changed by 90 °.
[0183]
In the cross dichroic mirror 85, the illumination light condensed by the main condenser 84 is reflected by the reflecting surface 85a of the cross dichroic mirror 85 and the traveling direction changes by 90 degrees, and the traveling direction is reflected by the reflecting surface 85b. It is separated into light that changes by 90 °.
[0184]
The projector device 80 also includes a first plane mirror 86, a first field lens 87, a B-PBS 88, and a first liquid crystal panel in the order of the optical path of the illumination light reflected by the reflecting surface 85a of the cross dichroic mirror 85. 89.
[0185]
The first plane mirror 86 is a plane-shaped mirror provided to reflect incident light, and is inclined at 45 ° with respect to the traveling direction of illumination light reflected by the reflecting surface 85a of the cross dichroic mirror 85. It is installed.
[0186]
The first field lens 87 is a convex lens configured to condense the illumination light reflected by the first plane mirror 86 onto the first liquid crystal panel 89.
[0187]
The B-PBS 88 is configured to separate the illumination light transmitted through the first field lens 87 by transmitting or reflecting the illumination light according to the polarization component. The B-PBS 88 has substantially the same configuration as the diffraction prism 15 or the diffraction prism 35 described above. For example, the B-PBS 88 transmits the P-polarized light and travels straight, and the S-polarized light is reflected by a reflecting surface 88a inclined by 45 ° with respect to the optical path. Reflect and change the direction of travel by 90 °.
[0188]
The first liquid crystal panel 89 receives a blue video signal among video signals separated for each of the three primary colors of light, displays a pattern based on the blue video signal, and receives illumination light. The irradiation light is modulated and reflected. The first liquid crystal panel 89 is a liquid crystal panel in which liquid crystal molecules are sealed, and can modulate light for each pixel.
[0189]
In the B-PBS 88, the illumination light transmitted through the first field lens 87 and the reflected light modulated by the first liquid crystal panel 89 are reflected by the light passing through the B-PBS 88 and traveling straight and reflected by the reflection surface 88a. Thus, the light is separated into light whose traveling direction changes by 90 °.
[0190]
Furthermore, the projector device 80 includes a second flat mirror 90 and a dichroic mirror 91 in the order of the optical path of the illumination light reflected by the reflecting surface 85 b of the cross dichroic mirror 85.
[0191]
The second plane mirror 90 is a planar mirror provided to reflect incident light, and is inclined at 45 ° with respect to the traveling direction of the illumination light reflected by the reflecting surface 85b of the cross dichroic mirror 85. It is installed.
[0192]
The dichroic mirror 91 is provided at an angle of 45 ° with respect to the optical path of the illumination light reflected by the second plane mirror 90, and transmits or reflects according to the wavelength band of the illumination light reflected by the second plane mirror 90. To be separated. The dichroic mirror 91 is composed of a dielectric multilayer film or the like. For example, light in the green wavelength band is reflected by a reflecting surface 91a inclined by 45 ° with respect to the optical path, the traveling direction is changed by 90 °, and the red wavelength is changed. Transmit light in the band and go straight.
[0193]
Furthermore, the projector device 80 includes a second field lens 92, an R-PBS 93, and a second liquid crystal panel 94 in the order of the optical path of the illumination light transmitted through the dichroic mirror 91.
[0194]
The second field lens 92 is a convex lens that condenses the illumination light transmitted through the dichroic mirror 91 on the second liquid crystal panel 94.
[0195]
The R-PBS 93 is configured to transmit or reflect the illumination light according to the polarization component of the illumination light transmitted through the second field lens 92 and separate it. The R-PBS 93 has substantially the same configuration as the diffraction prism 15 or the diffraction prism 35 described above. For example, the R-PBS 93 is a reflection surface 93a that transmits P-polarized light and travels straight and tilts S-polarized light by 45 ° with respect to the optical path. Reflect and change the direction of travel by 90 °.
[0196]
The second liquid crystal panel 94 receives a red video signal among video signals separated for each of the three primary colors of light, displays a pattern based on the red video signal, and receives illumination light. The irradiation light is modulated and reflected. The second liquid crystal panel 94 is a liquid crystal panel in which liquid crystal molecules are sealed, and can modulate light for each pixel.
[0197]
In the R-PBS 93, the illumination light transmitted through the second field lens 92 and the reflected light modulated by the second liquid crystal panel 94 are reflected by the light that passes straight through the R-PBS 93 and reflected by the reflecting surface 93a. Thus, the light is separated into light whose traveling direction changes by 90 °.
[0198]
Furthermore, the projector device 80 includes a third field lens 95, a G-PBS 96, and a third liquid crystal panel 97 in the order of the optical path of the illumination light reflected by the dichroic mirror 91.
[0199]
The third field lens 95 is a convex lens configured to collect the illumination light reflected by the dichroic mirror 91 on the third liquid crystal panel 97.
[0200]
The G-PBS 96 is configured to transmit or reflect the illumination light according to the polarization component of the illumination light transmitted through the third field lens 95 and separate it. The G-PBS 93 has substantially the same configuration as the diffraction prism 15 or the diffraction prism 35 described above. For example, the G-PBS 93 transmits the P-polarized light and travels straight, and the S-polarized light is inclined by 45 ° with respect to the optical path. Reflect and change the direction of travel by 90 °.
[0201]
The third liquid crystal panel 97 receives a green video signal among video signals separated for each of the three primary colors of light, displays a pattern based on the green video signal, and receives illumination light. The irradiation light is modulated and reflected. The third liquid crystal panel 97 is a liquid crystal panel in which liquid crystal molecules are sealed, and can modulate light for each pixel.
[0202]
In the G-PBS 96, the illumination light transmitted through the third field lens 95 and the reflected light modulated by the third liquid crystal panel 97 are reflected by the light passing through the G-PBS 96 and traveling straight and reflected by the reflecting surface 96a. Thus, the light is separated into light whose traveling direction changes by 90 °.
[0203]
Furthermore, the projector device 80 reflects reflected light modulated by the first liquid crystal panel 89 that has passed through the B-PBS 88, reflected light modulated by the second liquid crystal panel 94 that has passed through the R-PBS 93, and G- A synthesis prism 98 is provided in the direction of travel with the reflected light modulated by the third liquid crystal panel 97 that has passed through the PBS 96.
[0204]
The composite prism 98 transmits the reflected light modulated by the first liquid crystal panel 89 that has passed through the B-PBS 88, the reflected light modulated by the second liquid crystal panel 94 that has passed through the R-PBS 93, and the G-PBS 96. The reflected light modulated by the third liquid crystal panel 97 is transmitted or reflected according to the wavelength band to be combined. The synthetic prism 98 has a structure in which dielectric multilayer films having different characteristics are sandwiched by prisms so that their surfaces are orthogonal to each other. For example, light in the blue wavelength band is reflected by 45 ° with respect to the optical path. Reflected by the surface 98a, the traveling direction is changed by 90 °, light in the red wavelength band is reflected by the reflecting surface 99b inclined by 45 ° with respect to the optical path, the traveling direction is changed by 90 °, and the light in the green wavelength band is transmitted. Let go straight.
[0205]
In the combining prism 98, the reflected light modulated by the first liquid crystal panel 89 that has passed through the B-PBS 88 is reflected by the reflecting surface 98 a and the traveling direction is changed by 90 °, and the second liquid crystal panel 94 that has passed through the R-PBS 93. The reflected light modulated in step (b) is reflected by the reflecting surface 98b to change the traveling direction by 90 °, and the reflected light modulated by the third liquid crystal panel 97 transmitted through the G-PBS 96 is transmitted and travels straight. Output to.
[0206]
Furthermore, the projector device 80 modulates the reflected light modulated by the first liquid crystal panel 89 reflected by the reflecting surface 98a of the combining prism 98 and the second liquid crystal panel 94 reflected by the reflecting surface 98b of the combining prism 98. A projection lens 99 is provided in the traveling direction of the reflected light and the reflected light modulated by the third liquid crystal panel 97 that has passed through the combining prism 98.
[0207]
The projection lens 99 reflects the reflected light modulated by the first liquid crystal panel 89 reflected by the reflecting surface 98 a of the combining prism 98 and the reflected light modulated by the second liquid crystal panel 94 reflected by the reflecting surface 98 b of the combining prism 98. This is a convex lens capable of enlarging and projecting both the light and the reflected light modulated by the third liquid crystal panel 97 that has passed through the combining prism 98, and can project an image on a screen or the like (not shown). Has been.
[0208]
Regarding the projector device 80 configured as described above, the operation of each unit will be described along the optical path of the illumination light emitted from the lamp 81.
[0209]
The illumination light emitted from the lamp 81 includes red, green, and blue wavelength bands that are the three primary colors of light, and is guided to the fly eye integrator 82 as non-polarized light.
[0210]
Next, the illumination light guided to the fly eye integrator 82 is transmitted with the illuminance distribution made uniform by the fly eye integrator 82, and is incident on the PS conversion composition element 83.
[0211]
Next, the illumination light incident on the PS conversion / combination element 83 transmits S-polarized light as it is, and P-polarized light is converted to S-polarized light, and all enters the main capacitor 84 as S-polarized light.
[0212]
Next, the illumination light incident on the main condenser 84 is collected by the main condenser 84 and enters the cross dichroic mirror 85.
[0213]
Next, the illumination light incident on the cross dichroic mirror 85 is S-polarized light including all of the red, green, and blue wavelength bands. The blue wavelength band is reflected by the reflecting surface 85a, and the traveling direction is changed by 90 °. The green wavelength band is reflected by the reflecting surface 85b, and the traveling direction is changed by 90 °. Note that the illumination light in the blue wavelength band and the illumination light in the red and green wavelength bands are separated so that the traveling directions are different by 180 °, and the illumination light in the blue wavelength band is guided to the first plane mirror 86. The illumination light in the red and green wavelength bands is guided to the second plane mirror 90.
[0214]
Here, of the illumination light separated by the cross dichroic mirror 85 described above, the optical path of the illumination light of the blue wavelength band reflected by the reflecting surface 85a of the cross dichroic mirror 85 and guided to the first flat mirror 86 Will be described.
[0215]
The illumination light guided to the first plane mirror 86 is S-polarized light in the blue wavelength band, is reflected by the first plane mirror 86, changes its traveling direction by 90 °, and is applied to the first field lens 87. Led.
[0216]
Next, the illumination light guided to the first field lens 87 is S-polarized light in the blue wavelength band, and is condensed on the first liquid crystal panel 89 by the first field lens 87, and B -Guided to PBS 88.
[0217]
Next, the illumination light guided to the B-PBS 88 is S-polarized light in the blue wavelength band, is reflected by the reflection surface 88a of the B-PBS 88, changes its traveling direction by 90 °, and is guided to the first liquid crystal panel 89. It is burned.
[0218]
Next, the illumination light guided to the first liquid crystal panel 89 is S-polarized light in the blue wavelength band, and is modulated and reflected by the first liquid crystal panel 89 on which a pattern based on the blue video signal is displayed. The traveling direction is changed by 180 °, and at this time, P-polarized light is generated and returned to the B-PBS 88.
[0219]
Next, the reflected light from the first liquid crystal panel 89 returned to the B-PBS 88 is P-polarized light in the blue wavelength band and S-polarized light that is OFF light, and the P-polarized light is the reflecting surface 88a of the B-PBS 88. Is transmitted to the combining prism 98, and the S-polarized light is reflected by the reflecting surface 88a, and the traveling direction is changed by 90 ° and returned to the first field lens 87 side.
[0220]
Next, the reflected light modulated by the first liquid crystal panel 89 guided to the combining prism 98 is reflected by the reflecting surface 98 a of the combining prism 98, changes the traveling direction by 90 °, and is guided to the projection lens 99.
[0221]
On the other hand, of the illumination light separated by the cross dichroic mirror 85 described above, the optical path of the illumination light in the red and green wavelength bands reflected by the reflecting surface 85b of the cross dichroic mirror 85 and guided to the second plane mirror 90 explain.
[0222]
The illumination light guided to the second plane mirror 90 is S-polarized light in the red and green wavelength bands, and is reflected by the second plane mirror 90 to change its traveling direction by 90 °, and is guided to the dichroic mirror 91. It is burned.
[0223]
Next, the illumination light guided to the dichroic mirror 91 is S-polarized light in the red and green wavelength bands, and the red wavelength band passes through the dichroic mirror 91 and is guided to the second field lens 92, so that the green light The wavelength band is reflected by the dichroic mirror 91 and guided to the third field lens 95.
[0224]
Here, of the illumination light separated by the dichroic mirror 85 described above, the optical path of the illumination light in the red wavelength band that is transmitted through the cross dichroic mirror 85 and guided to the second field lens 92 will be described.
[0225]
The illumination light guided to the second field lens 92 is S-polarized light in the red wavelength band, and is condensed on the second liquid crystal panel 94 by the second field lens 92, and is applied to the R-PBS 93. Led.
[0226]
Next, the illumination light guided to the R-PBS 93 is S-polarized light in the red wavelength band, is reflected by the reflecting surface 93a of the R-PBS 93, changes its traveling direction by 90 °, and is guided to the second liquid crystal panel 94. It is burned.
[0227]
Next, the illumination light guided to the second liquid crystal panel 94 is S-polarized light in the red wavelength band, and is modulated and reflected by the second liquid crystal panel 94 on which a pattern based on the red video signal is displayed. The traveling direction is changed by 180 °. At this time, P-polarized light is generated and returned to the R-PBS 93.
[0228]
Next, the reflected light from the second liquid crystal panel 94 returned to the R-PBS 93 is P-polarized light in the red wavelength band and S-polarized light that is OFF light, and the P-polarized light is the reflecting surface 93a of the R-PBS 93. Is transmitted to the combining prism 98, and the S-polarized light is reflected by the reflecting surface 93a, and the traveling direction is changed by 90 ° and returned to the second field lens 92 side.
[0229]
Next, the reflected light modulated by the second liquid crystal panel 94 guided to the combining prism 98 is reflected by the reflecting surface 98 b of the combining prism 98 and the traveling direction thereof is changed by 90 ° and is guided to the projection lens 99.
[0230]
On the other hand, of the illumination light separated by the dichroic mirror 91 described above, the optical path of the illumination light in the green wavelength band reflected by the dichroic mirror 91 and guided to the third field lens 95 will be described.
[0231]
The illumination light guided to the third field lens 95 is S-polarized light in the green wavelength band, and is condensed on the third liquid crystal panel 97 by the third field lens 95, and is applied to the G-PBS 96. Led.
[0232]
Next, the illumination light guided to the G-PBS 96 is S-polarized light in the green wavelength band, is reflected by the reflection surface 96a of the G-PBS 96, changes its traveling direction by 90 °, and is guided to the third liquid crystal panel 97. It is burned.
[0233]
Next, the illumination light guided to the third liquid crystal panel 97 is S-polarized light in the green wavelength band, and is modulated and reflected by the third liquid crystal panel 97 on which a pattern based on the green video signal is displayed. The traveling direction is changed by 180 °, and at this time, P-polarized light is generated and returned to the G-PBS 96.
[0234]
Next, the reflected light from the third liquid crystal panel 97 returned to the G-PBS 96 is P-polarized light in the green wavelength band and S-polarized light that is OFF light, and the P-polarized light is the reflecting surface 96a of the G-PBS 96. Is transmitted to the combining prism 98, and the S-polarized light is reflected by the reflecting surface 96a, and the traveling direction is changed by 90 ° and returned to the third field lens 95 side.
[0235]
Next, the reflected light modulated by the third liquid crystal panel 97 guided to the combining prism 98 passes through the combining prism 98 and travels straight and is guided to the projection lens 99.
[0236]
As described above, the light of each wavelength band separated into the three optical paths by the cross dichroic mirror 85 and the dichroic mirror 91 is incident on the liquid crystal panel corresponding to each wavelength band as illumination light. Modulated and reflected. Then, the reflected lights modulated by the respective liquid crystal panels are combined by the combining prism 98 and guided to the projection lens 99, and enlarged and projected onto the screen or the like by the projection lens 99.
[0237]
Such a projector device 60 uses the above-described diffraction prism 15 or diffraction prism 35 for the incident PBS 68, G-PBS 69, RB-PBS 72, and output PBS 76, respectively, so that the projector device 10 and / or the projector device described above. An effect equivalent to 30 can be obtained.
[0238]
Such a projector device 80 is equivalent to the projector device 10 and / or the projector device 30 described above by using the diffraction prism 15 or the diffraction prism 35 described above for the B-PBS 88, the R-PBS 93, and the G-PBS 96, respectively. The effect of can be obtained.
[0239]
Next, a projector device 100 shown in FIG. 9 will be described as a projector device capable of projecting a color image to which the present invention is applied.
[0240]
The projector apparatus 100 includes a lamp 101 serving as a light source that emits illumination light, a fly-eye integrator 102, a PS conversion composition element 103, a main capacitor 104, a field lens 105, and a PBS 106 in order of the optical path from the lamp 101 side. It has.
[0241]
The lamp 101 can emit white light including light in the wavelength bands of red, green, and blue, which are the three primary colors of light, necessary for displaying a color image. Such a lamp 101 includes a light emitter 101a that emits white light and a reflector 101b that reflects light emitted from the light emitter 101a. As the light emitter 101a of the lamp 101, for example, a high-pressure mercury lamp, a halogen lamp, a metal halide lamp, a xenon lamp, or the like is used. A concave mirror is used as the reflector 101b of the lamp 101, and it is preferable that the mirror surface has a shape with good circumferential efficiency. For example, the reflector 101b has a shape of a rotationally symmetric surface such as a rotating surface or a rotating ellipsoid. Yes.
[0242]
In order for the illumination light emitted from the lamp 101 to uniformly illuminate the effective area of the liquid crystal panel, which will be described later, the fly eye integrator 102 uses the illumination light as a light beam having a shape of the effective area of the liquid crystal panel, and uniformizes the illuminance distribution. Have been to. Such a fly-eye integrator 102 is also referred to as a multi-lens array. A combination of two small convex lenses arranged in an array is used to collect illumination light from the lamp 101 by the multi-lens array 102a on the lamp 101 side. However, a small point light source is created, and illumination light from each point light source is synthesized by the other multi-lens array 102b.
[0243]
The PS conversion combining element 103 is configured to align the polarization components of the illumination light in order to effectively use the illumination light from the lamp 101. The PS conversion / combination element 103 is configured by a λ / 2 plate, a polarization beam splitter, or the like. For example, the PS conversion combining element 103 can convert P-polarized light into S-polarized light, and transmits S-polarized light in incident illumination light. In addition, since the P-polarized light is converted to S-polarized light and output, all the illumination light can be converted to S-polarized light.
[0244]
The main capacitor 104 is a convex lens that condenses the illumination light transmitted through the PS conversion composition element 103.
[0245]
The field lens 105 is a convex lens configured to condense the illumination light collected by the main condenser 104 onto three liquid crystal panels described later.
[0246]
Note that these condenser lenses are not limited to convex lenses. For example, the function of the main capacitor 104 can also be obtained by decentering each lens element of the multi-lens array 102b of the fly-eye integrator 102 with respect to each lens element of the multi-lens array 102a.
[0247]
The PBS 106 is configured to transmit or reflect the illumination light according to the polarization component of the illumination light transmitted through the field lens 105 and separate it. The PBS 106 has substantially the same configuration as the diffraction prism 15 or the diffraction prism 35 described above. For example, the PBS 106 transmits P-polarized light and travels straight, and reflects S-polarized light by the reflecting surface 106a inclined by 45 ° with respect to the optical path. The traveling direction is changed by 90 °.
[0248]
In addition, the projector device 100 includes a separation / combination prism 107 in the traveling direction of the illumination light reflected by the reflection surface 106 a of the PBS 106.
[0249]
The separation / combination prism 107 reflects the illumination light at a reflection surface 107a that is inclined by 45 ° with respect to the optical path and orthogonal to each other according to the wavelength band of the illumination light reflected by the reflection surface 106a of the PBS 106, and reflected by the reflection surface 107b. Alternatively, the reflection surface 107a and the reflection surface 107b are transmitted and separated. The separation / combination prism 107 has a structure in which a dielectric multilayer film or the like is sandwiched between prisms so that the surfaces are orthogonal to each other. For example, a reflection surface in which light in the blue wavelength band is inclined by 45 ° with respect to the optical path. The light is reflected by 107a, the traveling direction is changed by 90 °, light in the green wavelength band is transmitted and traveled straight, and the light in the red wavelength band is reflected by the reflecting surface 107b inclined by 45 ° with respect to the optical path, and the traveling direction is 90 Change.
[0250]
Further, the projector device 100 transmits the illumination light transmitted through the first liquid crystal panel 108 and the reflection surfaces 107a and 107b of the separation / combination prism 107 in the traveling direction of the illumination light reflected by the reflection surface 107a of the separation / combination prism 107. A second liquid crystal panel 109 is provided in the traveling direction, and a third liquid crystal panel 110 is provided in the traveling direction of the illumination light reflected by the reflecting surface 107 b of the separation / combination prism 107.
[0251]
The first liquid crystal panel 108 receives a blue video signal among video signals separated for each of the three primary colors of light, displays a pattern based on the blue video signal, and receives illumination light. The irradiation light is modulated and reflected. The first liquid crystal panel 108 is a liquid crystal panel in which liquid crystal molecules are sealed, and can modulate light for each pixel.
[0252]
The second liquid crystal panel 109 receives a green video signal among video signals separated for each of the three primary colors of light, displays a pattern based on the green video signal, and receives illumination light. The irradiation light is modulated and reflected. The second liquid crystal panel 109 is a liquid crystal panel in which liquid crystal molecules are enclosed, and can modulate light for each pixel.
[0253]
The third liquid crystal panel 110 receives a red video signal among video signals separated for each of the three primary colors of light, displays a pattern based on the red video signal, and receives illumination light. The irradiation light is modulated and reflected. The third liquid crystal panel 110 is a liquid crystal panel in which liquid crystal molecules are sealed, and can modulate light for each pixel.
[0254]
In the separation / combination prism 107, the illumination light transmitted through the field lens 105 and the reflected light modulated by the first liquid crystal panel 108, the second liquid crystal panel 109, and the third liquid crystal panel 110 are separated into the separation / combination prism 107. Is separated into light that travels straight through and is reflected by the reflecting surface 107a or the reflecting surface 107b and whose traveling direction changes by 90 °.
[0255]
In the PBS 106, the reflected light modulated by the first liquid crystal panel 108, the second liquid crystal panel 109, and the third liquid crystal panel 110 passes through the PBS 106 and travels straight.
[0256]
Furthermore, the projector device 100 reflects the reflected light modulated by the first liquid crystal panel 108 transmitted through the reflective surface 106a of the PBS 106 and the reflected light modulated by the second liquid crystal panel 109 transmitted through the reflective surface 106a of the PBS 106. And a projection lens 111 in the traveling direction of the reflected light modulated by the third liquid crystal panel 110 that has passed through the reflective surface 106a of the PBS 106.
[0257]
The projection lens 111 includes reflected light modulated by the first liquid crystal panel 108 transmitted through the reflective surface 106a of the PBS 106, reflected light modulated by the second liquid crystal panel 109 transmitted through the reflective surface 106a of the PBS 106, and PBS 106 This is a convex lens that can enlarge and project the reflected light modulated by the third liquid crystal panel 110 that has passed through the reflective surface 106a, and can project an image on a screen (not shown) or the like. Has been.
[0258]
Regarding the projector device 100 configured as described above, the operation of each unit will be described along the optical path of the illumination light emitted from the lamp 101.
[0259]
The illumination light emitted from the lamp 101 includes red, green, and blue wavelength bands that are the three primary colors of light, and is guided to the fly eye integrator 102 as non-polarized light.
[0260]
Next, the illumination light guided to the fly-eye integrator 102 is transmitted with the illuminance distribution made uniform by the fly-eye integrator 102, and is incident on the PS conversion composition element 103.
[0261]
Next, the illumination light incident on the PS conversion / combination element 103 transmits the S-polarized light as it is, and the P-polarized light is converted into the S-polarized light, and all enters the main capacitor 104 as the S-polarized light.
[0262]
Next, the illumination light incident on the main condenser 104 is condensed by the main condenser 104 and guided to the field lens 105.
[0263]
Next, the illumination light guided to the field lens 105 is guided to the PBS 106 by the field lens 105 so as to be condensed on the first liquid crystal panel 108, the second liquid crystal panel 109, and the third liquid crystal panel 110.
[0264]
Next, the illumination light guided to the PBS 106 is S-polarized light including all the red, green, and blue wavelength bands, reflected by the reflecting surface 106 a of the PBS 106, changed in traveling direction by 90 °, and guided to the separation / combination prism 107. It is burned.
[0265]
Next, the illumination light incident on the separation / combination prism 107 is S-polarized light including all the red, green, and blue wavelength bands, and the blue wavelength band is reflected by the reflecting surface 107a, and the traveling direction is changed by 90 °. The green wavelength band is transmitted through the reflecting surface 107a and the reflecting surface 107b and travels straight and is guided to the second liquid crystal panel 109, and the red wavelength band is reflected by the reflecting surface 107b and changes its traveling direction. It is changed by 90 ° and guided to the third liquid crystal panel. Note that the illumination light in the blue wavelength band and the illumination light in the red wavelength band are separated so that the traveling direction differs by 180 °.
[0266]
Next, among the illumination lights separated by the separation / combination prism 107, the illumination light reflected by the reflection surface 107a of the separation / combination prism 107 and guided to the first liquid crystal panel 108 is S in the blue wavelength band. Polarized light and modulated by the first liquid crystal panel 108 on which a pattern based on a blue video signal is displayed and reflected to change the traveling direction by 180 °. At this time, P-polarized light is generated and returned to the separation / combination prism 107. It is. Among the illumination lights separated by the separation / combination prism 107 described above, the illumination light transmitted through the reflection surface 107a and the reflection surface 107b of the separation / combination prism 107 and guided to the second liquid crystal panel 109 has a green wavelength. The band is S-polarized light, which is modulated and reflected by the second liquid crystal panel 109 on which a pattern based on a green video signal is displayed, and changes the traveling direction by 180 °. At this time, P-polarized light is generated and separated and synthesized prism It returns to 107.
[0267]
Further, among the illumination lights separated by the separation / combination prism 107 described above, the illumination light reflected by the reflecting surface 107b of the separation / combination prism 107 and guided to the third liquid crystal panel 110 is S-polarized light in the red wavelength band. And is modulated and reflected by the third liquid crystal panel 110 on which a pattern based on the red video signal is displayed, and the traveling direction is changed by 180 °. At this time, P-polarized light is generated and returned to the separation / combination prism 107. .
[0268]
Next, the reflected light from the first liquid crystal panel 108 returned to the separation / combination prism 107 is P-polarized light in the blue wavelength band and S-polarized light that is OFF light, and is reflected by the reflective surface 107a to change the traveling direction. The angle is changed by 90 ° and returned to the PBS 106.
[0269]
The reflected light from the second liquid crystal panel 109 returned to the separation / combination prism 107 is P-polarized light in the green wavelength band and S-polarized light that is OFF light, and is transmitted through the reflective surface 107a and the reflective surface 107b. And go straight back to PBS 106.
[0270]
Further, the reflected light from the third liquid crystal panel 110 returned to the separation / combination prism 107 is P-polarized light in the red wavelength band and S-polarized light that is OFF light, and is reflected by the reflective surface 107b and travels in the traveling direction of 90. Changed and returned to PBS 106.
[0271]
Next, the reflected light from the first liquid crystal panel 108 returned to the PBS 106 is P-polarized light in the blue wavelength band and S-polarized light that is OFF light, and the P-polarized light is transmitted through the reflecting surface 106 a of the PBS 106. S-polarized light, which is OFF light, is guided by the projection lens 111, reflected by the reflecting surface 106a, changed in the traveling direction by 90 °, and returned to the lamp 101 side.
[0272]
The reflected light from the second liquid crystal panel 109 returned to the PBS 106 is P-polarized light in the green wavelength band and S-polarized light that is OFF light, and the P-polarized light is transmitted through the reflecting surface 106a of the PBS 106 and projected. S-polarized light, which is OFF light, is guided by the lens 111, reflected by the reflecting surface 106a, changed in the traveling direction by 90 °, and returned to the lamp 101 side.
[0273]
Further, the reflected light from the third liquid crystal panel 110 returned to the PBS 106 is P-polarized light in the red wavelength band and S-polarized light that is OFF light, and the P-polarized light is transmitted through the reflecting surface 106 a of the PBS 106 and projected. S-polarized light, which is OFF light, is guided by the lens 111, reflected by the reflecting surface 106a, changed in the traveling direction by 90 °, and returned to the lamp 101 side.
[0274]
As described above, the light in the respective wavelength bands separated into the three optical paths by the separation / combination prism 107 is incident on the liquid crystal panels corresponding to the respective wavelength bands as illumination light, and is modulated and reflected by the respective liquid crystal panels. The Then, the reflected lights modulated by the respective liquid crystal panels are combined by the separation / combination prism 107 and guided to the projection lens 111, and enlarged and projected onto the screen or the like by the projection lens 111.
[0275]
Such a projector device 100 can obtain the same effect as the projector device 10 and / or the projector device 30 described above by using the diffraction prism 15 or the diffraction prism 35 described above for the PBS 106.
[0276]
In the above description, a liquid crystal panel is used as the light modulation element. However, the present invention is not limited to this, and any type can be used as long as the element spatially modulates the polarization state.
[0277]
Further, instead of the diffraction grid 51 and the diffraction grid base material 52 shown in FIGS. 5 and 6, a light separation layer having a property of transmitting or reflecting light according to the wavelength component on a plate-like transparent base material. The prism base material 54 may be formed so that a plurality of flat plate members 55 are joined via the soft adhesive layer 56. Of course, the light separation layer may be formed directly on the predetermined flat plate member 55 without using a plate-like transparent member.
[0278]
【The invention's effect】
As described above, the prism according to the present invention has excellent light beam separation characteristics at a wide angle of incidence, and can suppress the occurrence of astigmatism even when used in an imaging optical system. In addition, because it has excellent separation characteristics, desired characteristics can be obtained without using a substrate with a high refractive index, so that equivalent performance can be obtained at a lower cost than PBS using dielectric multilayer films. it can. Moreover, since it is not necessary to use a base material with a high refractive index, cost reduction and weight reduction can be achieved. Furthermore, since the degree of freedom of combination of the materials of the respective constituent elements is high and desired characteristics can be easily obtained, they can be easily used in various optical systems.
[0279]
In addition, since a soft adhesive layer is provided between the grid base material and the prism base material, the stress generated inside can be reduced, optical distortion can be reduced, and the prism base can be reduced. Since the material is optically coupled with a plurality of flat plate members via a soft adhesive layer, the stress generated inside can be further reduced, and optical distortion can be reduced.
[0280]
In addition, since the projection device according to the present invention can maintain the separation characteristic at a high NA by using the above-described prism, it can project an image with good contrast and improve the light utilization efficiency. And bright images can be projected. Further, by using the above-described prism, it is possible to suppress the generation of astigmatism in the imaging optical system, so that a clear image can be projected. Furthermore, cost reduction and weight reduction can be achieved by using the above-described prism.
[0281]
In addition, since the prism can reduce optical distortion, black unevenness in the projected image can be suppressed, and distortion due to thermal stress can also be suppressed. Since the influence of heat generation due to increasing can be reduced, the brightness of an image projected by increasing the amount of light emitted from the light source can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a projector apparatus to which the present invention is applied.
FIG. 2 is a diagram showing a configuration of a prism to which the present invention is applied.
FIG. 3 is a diagram showing another configuration of a projector apparatus to which the present invention is applied.
FIG. 4 is a diagram showing a configuration of an optical member to which the present invention is applied.
FIG. 5 is a diagram showing a configuration in which a corner prism of a prism to which the present invention is applied has a laminated structure.
FIG. 6 is a diagram showing another configuration in which the corner prism of the prism to which the present invention is applied has a laminated structure.
FIG. 7 is a diagram showing another configuration of the projector apparatus configuration to which the present invention is applied.
FIG. 8 is a diagram showing still another configuration of the projector device configuration to which the invention is applied.
FIG. 9 is a diagram showing still another configuration of the projector device configuration to which the invention is applied.
FIG. 10 is a diagram showing a configuration of a conventional PBS.
FIG. 11 is a diagram showing a conventional diffraction grid PBS.
[Explanation of symbols]
15 Diffraction prism, 21 Diffraction grid, 22 Diffraction grid substrate, 23 Adhesive layer, 24 Prism substrate, 25 Diffraction grid medium

Claims (16)

A prism that transmits or reflects incident light according to a polarization component;
A substantially grid-like diffraction grid formed of metal;
A pair of diffraction grid substrates sandwiching the diffraction grid;
An adhesive layer provided on each side of the pair of diffraction grid bases facing the diffraction grid; and
A pair of block members respectively fixed to the pair of diffraction grid substrates via the adhesive layer,
A space formed by the diffraction grid and the pair of diffraction grid base materials is filled with a medium having a refractive index substantially equal to the block member,
The block member is formed by alternately laminating a plurality of plate-like members whose surfaces are mirror-polished through a soft adhesive layer having flexibility, and the prism is optically coupled. At least one of the plate-like members forming the block member is different in the shape of two laminated surfaces laminated via the soft adhesive layer, and the shape of the laminated surface is another plate shape adjacent to the laminated surface. The prism according to claim 1 , wherein the prism has the same shape as the laminated surface of the member. The block member is a prism having a triangular bottom surface having two sides intersecting substantially at right angles to each other, and the plurality of plate-like members are arranged so that the adhesion surface of the diffraction grid substrate and the laminated surface are parallel to each other. 3. The prism according to claim 2 , wherein the prism is formed by alternately laminating through the soft adhesive layer.   The prism according to claim 1, wherein the adhesive layer has flexibility. The block member is a prism having a triangular bottom surface having two sides intersecting substantially at right angles to each other,
The pair of diffractive grid base materials are arranged so as to be inclined along side surfaces having one side other than the two sides as a ridge with respect to the side surface having the two sides as a ridge, respectively. The prism according to claim 1. A light source that emits illumination light;
A condensing lens that condenses the illumination light emitted from the light source;
A prism that transmits or reflects light from the condenser lens according to a polarization component;
A light modulation element that modulates and reflects the illumination light transmitted or reflected by the prism;
A projection lens that magnifies and projects the reflected light modulated by the light modulation element reflected or transmitted by the prism;
The prism is provided on a substantially grid-like diffraction grid made of metal, a pair of diffraction grid base materials sandwiching the diffraction grid, and each surface side of the pair of diffraction grid base materials facing the diffraction grid. A gap formed by the diffraction grid and the pair of diffraction grid substrates, the adhesive layer and a pair of block members respectively fixed to the pair of diffraction grid substrates via the adhesive layer Are filled with a medium having a refractive index substantially equal to that of the block member ,
The projection device , wherein the block member is formed by alternately laminating a plurality of plate-like members whose surfaces are mirror-polished through a soft adhesive layer having flexibility . The projection apparatus according to claim 6 , further comprising a polarization unit that outputs the illumination light to the prism as light having a predetermined polarization direction between the light source and the prism. It said polarizing means, claims, characterized in that a pre-polarizing element which transmits light of a predetermined polarization component of the illumination light incident on the polarization conversion combining element or the prism, aligns the polarization component of the illumination light 8. The projection device according to 7 . The projection device according to claim 6 , wherein the adhesive layer has softness. The projection device according to claim 6 , wherein the prism is formed by laminating a plurality of plate-like members whose surfaces are mirror-polished with a soft adhesive layer having flexibility. A light separation layer provided on a plate-like substrate and having a property of transmitting or reflecting light according to a polarization component;
A pair of adhesive layers provided on the main surface side of the plate-like base material on which the light separation layer is not provided and on the main surface side of the light separation layer not in contact with the plate-like base material;
A pair of block members sandwiching the light separation layer via the adhesive layer, and the block members are alternately laminated via a soft adhesive layer having a plurality of plate-like members whose surfaces are mirror-polished. And a prism that is optically coupled . The prism according to claim 11 , wherein the adhesive layer has flexibility. 12. The prism according to claim 11 , wherein the block member is a prism having a triangular bottom surface having two sides intersecting at substantially right angles to each other. At least one of the plate-like members forming the block member has different areas of two laminated surfaces laminated via the soft adhesive layer, and the laminated surfaces of other plate-like members adjacent to the laminated surface are The prism according to claim 11, wherein the laminated surface has the same shape. A light source that emits illumination light;
A condensing lens that condenses the illumination light emitted from the light source;
A prism that transmits or reflects light from the condenser lens according to a polarization component;
A light modulation element that modulates and reflects the illumination light transmitted or reflected by the prism;
A projection lens that magnifies and projects the reflected light modulated by the light modulation element reflected or transmitted by the prism;
The prism is provided on a plate-like substrate, and has a light separation layer having a property of transmitting or reflecting light according to a polarization component, and a main surface side of the plate-like substrate on which the light separation layer is not provided And a pair of adhesive layers provided on the main surface side of the light separation layer that does not contact the plate-like substrate, and a pair of block members that sandwich the light separation layer via the adhesive layer, A projection apparatus characterized in that the block member is formed by alternately laminating a plurality of plate-like members whose surfaces are mirror-polished via soft adhesive layers having flexibility . 16. The projection apparatus according to claim 15 , further comprising a polarization unit that outputs the illumination light to the prism as light having a predetermined polarization direction between the light source and the prism.

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