WO2000073844A1 - Systeme optique a reflexion et projecteur reflectif contenant ce systeme - Google Patents

Systeme optique a reflexion et projecteur reflectif contenant ce systeme Download PDF

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Publication number
WO2000073844A1
WO2000073844A1 PCT/JP1999/005335 JP9905335W WO0073844A1 WO 2000073844 A1 WO2000073844 A1 WO 2000073844A1 JP 9905335 W JP9905335 W JP 9905335W WO 0073844 A1 WO0073844 A1 WO 0073844A1
Authority
WO
WIPO (PCT)
Prior art keywords
lens
optical system
reflective
reflector
panel
Prior art date
Application number
PCT/JP1999/005335
Other languages
English (en)
Japanese (ja)
Inventor
Masahiko Yatsu
Satoshi Ohuchi
Nobuo Masuoka
Hidehiro Ikeda
Original Assignee
Hitachi, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi, Ltd. filed Critical Hitachi, Ltd.
Publication of WO2000073844A1 publication Critical patent/WO2000073844A1/fr

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/24—Optical objectives specially designed for the purposes specified below for reproducing or copying at short object distances
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/02—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the intensity of light
    • G02B26/04—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the intensity of light by periodically varying the intensity of light, e.g. using choppers

Definitions

  • the present invention relates to a reflection type optical system and a reflection type projector device using the same, and is suitable for a front projection type or rear projection type projection projector, and also for a general projection type television. . Background art
  • reflective projectors are roughly classified into two types based on the characteristics of reflective panels:
  • the first is a method of vertically entering and reflecting on a reflective panel.
  • a half mirror or half prism is arranged on the optical axis of the projection lens, and the light beam of the illumination optical system passes through a part of the projection lens and is reflected through the half mirror or half prism.
  • Conventionally there is a method in which the light reaches the panel surface, is reflected, and is projected on the screen surface via a projection lens.
  • the second is a method in which a light beam enters the reflective panel from an oblique direction and is reflected by a minute mirror corresponding to each pixel in the reflective panel.
  • the optical axis of the incident optical system is obliquely arranged with respect to the entire reflective panel, and the center of the reflected light beam from the reflective panel is reflected perpendicularly to the entire reflective panel. It reaches the screen via a projection lens arranged perpendicular to the whole panel.
  • the reflection type light flux area is usually used for the incident light flux area and the reflected light flux area. There is a space in front of the panel.
  • the second method there is an example in which an incident light beam is guided to a reflective panel using a total reflection prism.
  • I bending of the optical path of the illumination optical system, air conversion of the total reflection prism
  • the length is shortened, and the back focus of the projection lens can be shortened accordingly.
  • the back focus of the projection lens required a large value of several tens of mm or more.
  • both the illumination optical system and the projection lens system be telecentric, in order to improve the overall light utilization efficiency of a reflective projector using a reflective panel.
  • FIG. 8 is a view showing a configuration in which an illumination optical system 3 and a projection lens 5 are arranged on the right side of the reflection type panel 4, and shows only reflected light rays immediately before and immediately after the reflection type panel 4.
  • the reflection-type panel 4 shown in the figure contains the D ⁇ ' ⁇ D (Digital M icrom irror Device) (registered trademark of Texas Instruments Inc.). This is because the number of minute mirrors corresponding to each pixel is equal to the number of pixels, and by changing the inclination from 110 degrees to +10 degrees, the reflected light is reflected by the projection lens 5 (shown in FIG. 8). ) And a state where it does not enter the projection lens 5.
  • D ⁇ ' ⁇ D Digital M icrom irror Device
  • FIG. 8 (1) shows a case where the pupil (light) of the illumination optical system 3 is located on the right side of the reflection type panel 4, and the incident light beam emitted from the pupil position! 3 is reflected by each mirror of the reflective panel 4 and becomes reflected light '3 ⁇ 4': '.
  • the incident ray the incident ray at the same angle as I is reflected by the reflective panel 4 and reflected at the same angle as the reflected ray 1 ', but the position of the pupil (pupil) is as shown in the figure.
  • the normal angle of the incident light 2 and 3 at the mirror on the reflective panel 4 is shifted, so that the reflected light 2 'and 3' That is, the pupil position of the projection lens 5 needs to be on the left side of the reflective panel 4.
  • FIG. 8 (2) shows the case where the pupil position of the illumination optical system 3 is located on the left side of the reflective panel. And reflected light rays become ' ⁇ ', '3', respectively.
  • An incident ray having the same angle as the incident ray 1 is reflected by the reflective panel 4 and is reflected at the same angle as the reflected ray 1 ', but conversely, if the pupil position is small at a finite distance as shown in the figure, Since the normal angles of the mirrors on the reflective panel 4 of the incident light rays 1 and 3 are shifted to the opposite side, the reflected light rays 1 'and 3' are reflected inward as shown in the figure. That is, the pupil position of the projection lens 5 needs to be on the right side of the reflective panel 4 in the figure.
  • the illumination optical system 3 and the projection lens 5 for the reflective panel 4 are on opposite sides of each other. Therefore, in order to solve this problem, if a telecentric or equivalent state can be achieved, even if the pupil positions are opposite to each other with respect to the reflective panel 4, the substantial angular difference is small. can do.
  • a common means of realizing telecentricity is to place a convex lens in front of the image plane or mapping plane.
  • An object of the present invention is to make the illumination optical system and the projection lens telecentric without increasing the number of lenses and without increasing the size of the entire lens system.
  • a quantitative supplementary explanation will be made using the calculation results of the light transmittance based on the difference in the pupil position in a certain calculation model.
  • Fig. 9 shows a table of the calculation results
  • Fig. 10 shows the graph.
  • the pupil position of the illumination optical system was provided on the illumination optical system side with respect to the reflection type panel, and the pupil position of the projection lens was provided on the projection lens side with respect to the reflection type panel. This is a typical pupil position when no field lens is used, and the sign is represented by a negative value.
  • the purpose is to clarify the degree of deterioration of the light transmittance when the pupil positions of the illumination optical system and the projection lens do not match, so the pupil position of the projection lens is as short as 150 mm.
  • the pupil position of the illumination optical system is 100 mm, 1200 mm, 500 mm, 1000 mm, and 200 mm
  • the pupil position of the illumination optical system should be as large as about 120 mm.
  • Projection lens When the pupil position of the illumination optical system is as small as 150 mm and cannot be called telecentric, even if the pupil position of the illumination optical system is 100 mm, the light transmittance will be large. Deterioration can be quantitatively confirmed.
  • An object of the present invention is to provide a technique capable of displaying a high-luminance image with improved pseudo contours at high gradations in addition to high definition. Disclosure of the invention
  • a field lens with a positive focal length which is a part of the projection lens and is coaxial with the optical axis of the projection lens, is placed between the total reflection prism and the reflective panel, and passes through the field lens
  • the arrangement of the field lens and the illumination optical system is specified so that the optical axis of the illumination light before reflection is incident on the reflective panel at a predetermined angle at a predetermined angle at a predetermined angle after bending by the above-mentioned field lens.
  • FIG. 1 is a diagram showing a basic configuration of an optical system according to an embodiment of the present invention
  • FIG. 2 is an explanatory diagram of an operation of a field lens according to an embodiment of the present invention
  • FIG. 3 is an embodiment of the present invention.
  • FIG. 4 is a second configuration diagram using a lens array according to an embodiment of the present invention
  • FIG. 5 is a diagram illustrating the shape of a conventional lens array
  • FIG. 6 is an explanatory view of the shape of the lens array according to the embodiment of the present invention
  • FIG. 7 is a configuration diagram using the rod lens of the embodiment of the present invention
  • FIG. 8 is a field array of the present invention.
  • Fig. 9 is a diagram explaining the reason for the telecentricity by the lens
  • Fig. 9 is a diagram explaining the reason for the telecentricity by the lens, Fig.
  • Fig. 9 is the calculation result of the light transmittance based on the difference between the pupil position of the illumination optical system and the pupil position of the projection lens
  • Fig. 10 is the illumination optical system
  • Fig. 11 shows the calculation results of the ray transmittance based on the difference between the pupil position of the projection lens and the pupil position of the projection lens.
  • Fig. 13 shows the spatial relationship between the light flux and the reflected light flux.
  • Fig. 13 shows the state of incident light and reflected light when the total reflection prism is placed immediately before the reflective panel.
  • Fig. 15 shows a configuration in which a total reflection prism is composed of two triangular prisms of the same shape
  • Fig. 15 shows a configuration in which a total reflection prism and a field lens are bonded
  • Fig. 16 shows Fig. 17 is a block diagram in which a total reflection prism and a field lens are integrally molded with a mold.
  • Fig. 17 is a specific shape diagram of an embodiment in which a total reflection prism and a field lens are bonded. It is. BEST MODE FOR CARRYING OUT THE INVENTION
  • FIG. 1 is a basic configuration diagram of an optical system of a reflection type projection device according to an embodiment of the present invention.
  • 1 is a lamp
  • 2 is a reflector
  • 4 is a reflective panel
  • 5 is a projection lens
  • 6 is a field lens
  • 7 is a color wheel as color separation means
  • 20 is a total reflection prism.
  • Reference numeral 3 denotes an illumination optical system from a lamp 1 to a field lens 6.
  • the field lens 6 can be interpreted as a part of the projection lens 5, but here, the field lens 6 and the projection lens 5 will be distinguished from each other based on their functions.
  • the reflector 2 is an elliptical reflector whose cross-sectional shape is an elliptical surface.
  • the reflector 2 is located at or near the first focal point of the reflector 2.
  • the emitted light beam forms an image at or near the second focal position of the reflector 2 to form a spot image.
  • a portion of the color mirror of the color wheel 7 rotates at the position of the spot image, and is separated into colors such as R, G, and B.
  • the luminous fluxes of R, G, B, etc., separated by the color wheel 7 are totally reflected by the total reflection prism 20 and then converted into telecentric luminous fluxes by the field lens 6 to be incident at a predetermined incidence.
  • the light enters the reflective panel 4 at an angle.
  • the light beam reflected by the reflective panel 4 passes through the field lens 6 again, and then passes through the total reflection prism 20. Finally, the light is projected through a projection lens 5 onto a screen surface (not shown). The state before and after reflection by the reflective panel 4 will be described with reference to FIG.
  • Fig. 2 shows how rays on the optical axis of the illumination optical system 3 (a straight line connecting the vertices of the lamp 1 and the reflector 2) enter the field lens 6 and the reflective panel 4. It is the schematic which showed whether it reflects.
  • DMD described in the above-mentioned magazine “Photo Industry” is used.
  • this DMD there are minute mirrors corresponding to each pixel for the number of pixels, and by changing the inclination from 110 degrees to +1 () degrees, reflected light is reflected by the projection lens 5 (Fig. (Not shown) and a state where it does not enter the projection lens 5.
  • the states of 0N and 0FF of each pixel of the reflective panel 4 are created.
  • a ray overlapping the ray on the optical axis of the illumination optical system 3 (a straight line connecting the vertexes of the lamp 1 and the reflector 2) is refracted by the field lens 6 and is reflected on the entire surface of the reflective panel 4.
  • the incident light is incident at an angle of 20 degrees with respect to the normal, and the reflected light is emitted from the reflective panel 4 perpendicularly while the micromirrors are inclined at 10 degrees.
  • This light beam reaches the projection lens 5 via the field lens 6 which is arranged on the optical axis of the reflection type panel 4 without tilting.
  • the reflection angle is twice the angle of 20 degrees and differs by 40 degrees, and does not enter the projection lens 5.
  • FIG. 2 shows a diagram in which the 0N light reflected at the center of the reflective panel 4 overlaps the optical axis of the projection lens 5.
  • the projection lens 5 A so-called optical axis shift is performed in which the optical axis of the reflective panel 4 and the center position of the reflective panel 4 are shifted.
  • incident light overlapping the optical axis of the illumination optical system is reflected by the optical axis of the projection lens 5 at the center of the reflective panel 4. Is almost parallel to.
  • Equation 1 t X ta ⁇ 7 (Equation 1)
  • ⁇ arcsin ((sin a) /) (Equation 2)
  • FIG. 3 is a configuration diagram using a lens array type integrator in the basic configuration of FIG. 8 is one or more first convex lenses, 9 is one or more second convex lenses, 10 is a first flat lens array, 11 is a second flat lens.
  • a lens array 12 is a light condensing lens having one or more convex lenses.
  • a parabolic reflector having a parabolic cross-sectional shape is used as the reflector 2, and one or more sheets for forming a spot image on the seven color wheels are used.
  • the first convex lens 8 is arranged.
  • one or more second convex lenses 9 are required to convert the spot image into a parallel light beam again.
  • FIG. 4 an elliptical reflector having an elliptical cross section is used for the reflector 2, so that the first convex lens 8 in FIG. 3 is unnecessary.
  • the basic configuration and basic operation are the same as in FIG.
  • FIG. 5 and FIG. 6 are explanatory diagrams of a lens array in a lens array system.
  • the basic function of the lens array method is that the light intensity distribution of each cell (individual lens) in the first flat lens array 10 is superimposed on the panel surface.
  • a rectangular cell having a rectangular shape is used as the cell on the flat lens array 10.
  • the 1 / cos 20 degrees may be considered without considering the trapezoidal distortion caused by the magnification difference due to the image plane position shift. Therefore, the shape of each cell of the first flat lens array 10 may be compressed in advance by cos 20 degrees in the direction in which the mirror rotates 10 degrees in soil.
  • 13 is a rod lens
  • 14 is a relay lens system having one or more convex lenses.
  • the reflector 2 an elliptical reflector having an elliptical cross section is used, and a spot image is formed directly on the seven surfaces of the color wheel.
  • the light beam incident on the rod lens 13 immediately after the color wheel 7 exits from the exit surface of the rod lens 13 and is reflected by the relay lens system 14 and the total reflection prism 20 to the reflection type panel 4.
  • An image of rod lens 13 is formed on the surface.
  • the light beam incident on rod lens 13 is incident on rod lens 13 at the incident surface, and is incident on the side surface of force rod lens 13 having an angular distribution due to the light distribution of lamp 1 itself.
  • the uniformity of the light flux distribution on the exit surface of the rod lens 13 is improved. Since the relay lens system 14 has a mapping relationship in which the exit surface of the rod lens 13 is the object plane and the four reflective panels are the image plane, the uniform distribution improved by the rod lens 13 is obtained.
  • the luminous flux is guided to the four reflective panels.
  • FIG. 11 is a schematic diagram showing the state of the incident light beam and the reflected light beam on the reflection panel 4 with reference to the reflection panel 4.
  • the luminous flux from the illumination optical system is incident on the reflective panel 4 at an incident angle of 20 degrees, and the reflected panel 4 changes the angle by 20 degrees to become a reflected luminous flux.
  • the optical components of the incident optical system are arranged, and for the reflected light beam, the optical components of the reflective optical system are arranged.However, if the light beam diameter of the incident light beam is large, the reflected light beam Some of them cannot fit in the reflection optical system. Therefore, in practice, the size of the incident light beam is limited so that the optical paths of the incident light beam and the reflected light beam do not physically interfere as shown in FIG.
  • the boundary between the incident light beam and the reflected light beam at the center of the panel and the boundary line between the incident light beam and the reflected light beam around the panel, which can be similarly drawn, are in a parallel relationship. Therefore, the light flux of the illumination optical system, which is the incident light flux, enters the panel via a mirror or the like. Since the mirror arrangement area required for reflection is different between the center of the panel and the periphery of the panel, the incident light beam is ideally applied to the center and the periphery of the panel via the reflection mirror. Can not do.
  • FIG. 13 is a diagram showing optical paths of incident light and reflected light on the reflection panel 4 in the total reflection prism 20.
  • the light reflected at the center of the reflection panel 4 and the light incident on the periphery of the reflection panel 4 are totally reflected for clarity in the figure. This shows a state where the prism 20 passes through almost the same place.
  • the angle of incidence of the incident ray with respect to the normal line of the total reflection prism 20 and the reflected ray after being reflected by the reflective panel 4 differs by 20 degrees, and as a result, the total reflection surface prism 2
  • the angle of incidence with respect to the normal to 0 is smaller by 20 degrees, and the light is transmitted without being totally reflected by the total reflection surface.
  • the on-axis ray and the principal ray of the illumination optical system are shown as representatives.In actuality, however, the representative ray is a luminous flux obtained by adding an F-value ray.
  • the reference of the reflected light flux is 0 degree
  • FIG. 14 shows an example in which a total reflection prism 20 is formed by bonding two prism blocks having the same shape.
  • the cost of the total reflection prism 20 can be reduced.
  • it is reflected by the reflective panel 4.
  • the angle is preserved, so considering the F value of the projection lens 5, However, since reflection inside the lens barrel of the projection lens 5 may be considered, it is desirable to prevent the above total reflection for the contrast performance.
  • FIG. 15 is a diagram showing the operation of the present invention.
  • the shape of the field lens 6 is set such that the surface on the reflective panel 4 side is a convex surface and the surface on the opposite side is a flat surface. Further, the configuration is such that the field lens 6 is attached to the total reflection prism 20. The purpose of this is to reduce reflections such as ghost caused by the lens surface of the field lens 6 and the surface of the total reflection prism 20, respectively, and to achieve a good optical system with good contrast. .
  • the prism constituting the field lens 6 and the prism forming the total reflection prism 20 are molded integrally with plastic, the position of the bonding is adjusted. Work can be eliminated.
  • FIG. 17 is a view showing a specific shape in the case of the embodiment in which the field lens 6 and the total reflection prism 20 are bonded.
  • BK 7 commonly known as BK 7
  • N refractive index
  • two prisms whose interior angles of the triangle are 100 degrees, 3.396 degrees and 46.4 degrees are used.
  • the field lens 6 was 3 mm thick, with the convex surface having a radius of curvature of 84.5 mm facing the reflective panel 4 side.
  • the distance from the field lens 6 to the mirror reflecting surface of the reflective panel 4 was 10.3 mm in air conversion.
  • the TIR prism Total Internal Reflection Prism
  • the lens array method and the rod lens method are shown as an integral view.
  • any optical element having the same optical action can be used. Good.
  • the technology according to the present invention relates to a reflection type projector device, and can be widely used for a front projection type or a rear projection type projector. Furthermore, it can be widely used in fields such as general projection televisions.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Projection Apparatus (AREA)
  • Lenses (AREA)

Abstract

L'invention concerne une lentille de champ constituant une lentille de projection, qui est alignée sur l'axe optique de la lentille de projection et possède une longueur focale positive. La lentille de champ est disposée en face d'un panneau de réflexion, et cette disposition de la lentille de champ et d'un système optique d'éclairage est déterminée des sorte que l'axe optique de la lumière d'éclairage tombe, avant de passer à travers la lentille de champ et après avoir été réfracté par la lentille de champ, selon un angle préétabli, sur le centre général du panneau de réflexion. Le système optique d'éclairage et la lentille de projection peuvent être rendus télécentriques sans augmentation du nombre de lentilles ou agrandissement de l'ensemble du système de lentille.
PCT/JP1999/005335 1999-05-28 1999-09-29 Systeme optique a reflexion et projecteur reflectif contenant ce systeme WO2000073844A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP14932699 1999-05-28
JP11/149326 1999-05-28

Publications (1)

Publication Number Publication Date
WO2000073844A1 true WO2000073844A1 (fr) 2000-12-07

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003149599A (ja) * 2001-11-15 2003-05-21 Casio Comput Co Ltd 投影型表示装置
JP2004341105A (ja) * 2003-05-14 2004-12-02 Nec Viewtechnology Ltd 投写型表示装置
JP2009031800A (ja) * 2008-08-06 2009-02-12 Casio Comput Co Ltd 投影型表示装置
JP2010244074A (ja) * 2010-07-05 2010-10-28 Seiko Epson Corp 投射型表示装置
JP2010262312A (ja) * 2010-08-09 2010-11-18 Ｎｅｃディスプレイソリューションズ株式会社 投写型表示装置
JP2012185479A (ja) * 2011-02-17 2012-09-27 Nikon Corp 投射型表示装置、携帯型電子機器およびデジタルカメラ

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0815639A (ja) * 1994-06-27 1996-01-19 Canon Inc 変形ミラー型空間光変調素子を用いた投射型表示装置
US5552922A (en) * 1993-04-12 1996-09-03 Corning Incorporated Optical system for projection display
US5640479A (en) * 1995-10-18 1997-06-17 Palomar Technologies Corporation Fiberoptic face plate stop for digital micromirror device projection system
JPH11133353A (ja) * 1997-10-31 1999-05-21 Minolta Co Ltd 像投影装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5552922A (en) * 1993-04-12 1996-09-03 Corning Incorporated Optical system for projection display
JPH0815639A (ja) * 1994-06-27 1996-01-19 Canon Inc 変形ミラー型空間光変調素子を用いた投射型表示装置
US5640479A (en) * 1995-10-18 1997-06-17 Palomar Technologies Corporation Fiberoptic face plate stop for digital micromirror device projection system
JPH11133353A (ja) * 1997-10-31 1999-05-21 Minolta Co Ltd 像投影装置

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003149599A (ja) * 2001-11-15 2003-05-21 Casio Comput Co Ltd 投影型表示装置
JP2004341105A (ja) * 2003-05-14 2004-12-02 Nec Viewtechnology Ltd 投写型表示装置
JP2009031800A (ja) * 2008-08-06 2009-02-12 Casio Comput Co Ltd 投影型表示装置
JP2010244074A (ja) * 2010-07-05 2010-10-28 Seiko Epson Corp 投射型表示装置
JP2010262312A (ja) * 2010-08-09 2010-11-18 Ｎｅｃディスプレイソリューションズ株式会社 投写型表示装置
JP2012185479A (ja) * 2011-02-17 2012-09-27 Nikon Corp 投射型表示装置、携帯型電子機器およびデジタルカメラ
US8827464B2 (en) 2011-02-17 2014-09-09 Nikon Corporation Projection display device, portable electronic apparatus and digital camera

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