United States Patent
`5,108,172
`[11] Patent Number:
`Flasck
`[45] Date of Patent: Apr. 28, 1992
`
`
`
`[19]
`
`IllllllllllllllllllllllllllIlllllllllllllllllllllllllllllllllllllllllllllll
`0500510817211
`
`154]
`
`[75]
`
`I73]
`
`[2 ll
`
`[22]
`
`163]
`
`151]
`152]
`
`[58]
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`[56]
`
`ACTIVE MATRIX REFLECTIVE IMAGE
`PLANE MODULE AND PROJECTION
`SYSTEM
`
`Inventor: Richard A. Flasck. San Ramon, Calif.
`
`Assignee: RAF Electronics Corp., San Ramon,
`Calif. ,
`
`Appl. 190.: 587,347
`
`Filed:
`
`Sep. 24. 1990
`
`Related US. Application Data
`Continuation-impart of Ser. No. 392.746. Aug. 11.
`1989. Pat. No. 5.022.750.
`
`Int. Cl.5 .............................................. 6038 21/28
`US. C1. ........................................ 353/31; 353/37;
`353/98; 359/68
`Field of Search ....................... 353/31. 34. 37. 66,
`353/98. 64, 82, 84. 55, 99. 30; 350/334
`References Cited
`[15. PATENT DOCUMENTS
`
`3.486.817 12/1969 Hubner ................................. 353/98
`3.525.566 8/1970 Altman .....
`353/66
`
`3.673.932 7/1972 Rottmiller
`353/81
`
`3.807.831
`4/1974 Soref ........
`.. 350/150
`
`3.824.(X)3 7/1974 Koda et al.
`.. 350/160
`
`4.368.963
`1/1983' Stolov ..
`353/31
`4.470.060 9/ 1984 Yamazak .......... 357/41
`
`
`4.574.282 3/1986 Crossland et a .
`.. 340/784
`
`4.582.395 4/1986 Morozumi
`...... 350/334
`
`.. 350/339 F
`4.716.403 12/1987 Morozumi
`4.745.454 5/1988 Erb ....................... 357/51
`
`.. 340/784
`4.804.953 2/1989 Casueberry ..
`4.818.074 4/1989 Yokoi et al. ............ 350/338
`
`4.838.654 6/1989 Hamaguchi et a1.
`.
`...... 350/333
`
`4.839.707 6/ 1989 Shields ....................... 357/237
`
`....................... 357/51
`4.908.692
`3/1990 Kikuchi et al.
`
`................. 350/333
`4.936.656 6/1990 Yamashita et al.
`4.943.154 7/1990 Miyatalte et al. ......... 353/31
`
`4.943.156 7/1990 Vanderwetf .......... 353/38
`
`4.944.576 7/ 1990 Lacker et al.
`350/334
`4.969.730 11/1990 van den Brandt
`..... 353/31
`
`
`Primary Examiner—William A. Cuchlinski, Jr.
`Asrimtm Examiner—William C. Dowling
`Attorney, Agent. or Firm—Foley & Lardner
`
`[57]
`
`ABSTRACT
`
`An improved active matrix reflective projection system
`utilizing a conventional wafer includes a reflective
`image plane module forming two focal images. The
`image plane module includes light directing and reflect‘
`ing structures and a wafer based active matrix. A source
`of light is directed to the image plane module active
`matrix from a first image plane. The active matrix im-
`parts information onto alight beam reflected therefrom.
`The image plane module projects the reflected beam for
`viewing. such as through one or more lens. The active
`matrix reflective projection system can be a mono-
`chrome projector including a single reflective image
`plane module or can be a full color system including
`three reflective image plane modules. Each color image
`plane module operates on a single color component,
`red. green or blue. which then are combined on a screen
`or before projecting on the screen to form the full color
`projection image. The active matrix includes a specular
`reflective back surface and an LC or similar type mate-
`rial forrned thereon which is electronically altered to
`impart the information to the light beam reflected there-
`from. The image plane module includes a mirror or
`mirror portion which directs the light or light compo-
`nent to the wafer based active matrix which reflects an
`encoded light beam therefrom and which projects the
`reflected light to be viewed.
`
`34 Claims. 11 Drawing Sheets
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`US. Patent
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`Apr. 28, 1992
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`U.S. Patent
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`Apr. 28, 1992
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`1
`
`5,108,172
`
`ACTIVE MATRlX REFLECTIVE IMAGE PLANE
`MODULE AND PROJECTION SYSTEM
`
`CROSS REFERENCE TO RELATED
`APPLICATION
`
`This application is a continuation-in-part of US. Ser.
`No. 392,746, filed Aug. ll. 1989, now US. Pat. No.
`5.022.570 the disclosure of which is incorporated herein
`by reference.
`.
`BACKGROUND OF THE INVENTION
`
`The invention relates generally to projection systems
`and more particularly to an improved active matrix
`reflective image plane module and projection system.
`During the last two decades, there have been numer-
`ous efforts to develop and commercialize flat panel
`displays to effectively compete with the conventional
`cathode ray tube (CRT) or to develop products which
`are not possible utilizing CRT‘s. Of these efforts. plasma
`display panels (PDP), electroluminescent displays (EL)
`and several types of liquid crystal displays (LCD) have
`clearly been the most successful and have exhibited the
`most dynamic growth and future potential. One specific
`type of display, active matrix liquid crystal displays
`(AMLCD). has demonstrated sufficient performance to
`address some major market segments
`The cost of AMLCD's is largely determined by the
`yield of useable devices. where the yield is the percent-
`age of useable devices from the total produced. Yield of
`.AMLCD'S is in large part determined by the device
`design. manufacturing process tolerance and the display
`size. In general. the larger the display size. the lower the
`yield and hence higher the cost of the device.
`The focus of effons in recent years has been in devel-
`oping direct view display sizes large enough to replace
`existing TV and computer monitors. Pocket TV‘s have
`been introduced having one to three inch wide display
`screens. with the expressed goal of producing larger
`displays as volume and yield increase. An intense effort
`is being made to produce a fourteen inch diagonal or
`larger display. The ultimate goal of some efforts is to
`produce wall size direct view displays for the TV mar-
`ket. This goal is very likely to be frustrated by the inher-
`ent obstacles in producing a CRT or any other type of
`direct view display of that size.
`The AMLCD effort has concentrated on utilizing a
`matrix of nonlinear devices on a glass or fused silica
`substrate. The nonlinear devices allow individual con-
`trol over each display picture element or “pixel“ to
`provide superior optimal performance. The nonlinear
`devices generally are amorphous or polycrystalline
`silicon thin film transistors (TFT); however, thin film
`diodes (1'PD) and metal-insulator-metal (MIM) devices
`also have been employed.
`A transparent substrate is considered necessary for
`these displays. because most liquid crystal (LC) materi-
`als require a polarizer at both the front and the back of
`the LCD device. Further, the conventional position on
`color diSplays is that they must be transmissive rather
`than reflective, because of the light losses inherent in
`the color reflective mode.
`In developing larger size displays, substrate cost be-
`comes important. Amorphous silicon TFT AMLCD's
`utilize inexpensive drawn glass. Polycrystalline silicon
`on the other hand. requires either very high tempera-
`ture glass or fused silica substrates. Either of these sub-
`strates is prohibitively expensive in widths over eight
`
`5
`
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`
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`inches. The inexpensive amorphous silicon AMLCD
`substrates are offset by the fact that these displays re-
`quire separate address devices which result in several
`hundred interconnections to the display substrate. Poly-
`crystalline silicon AMLCD‘s allow integration of the
`addressing circuitry on the substrate which reduces the
`number of interconnections to a very few.
`The first direct view AMLCD utilizing a single crys-
`tal silicon wafer was produced in the early 1970‘s. Work
`on this development continued into the early l980‘s,
`utilizing standard crystal silicon wafers and wafer fabri-
`cation techniques. This work appears to vinually have
`been abandoned since the display sizes are limited to less
`than the available wafer size and because the wafers are
`not transparent. These devices utilized dynamic scatter-
`ing guest-host or dyed phase change rather than con-
`ventional twisted nematic LC material, which required
`expensive and elaborate photolithography to produce
`the required diffuse reflective aluminum back surface.
`These devices do provide fast. high performance and
`stable displays with integrated address and drive cir-
`cuitry.
`New markets have been recognized which include
`home theatre high definition TV. audio visual machines
`and high resolution large area computer aided design
`(CAD) stations. Each of these markets require very
`large. high resolution. full color and video speed imag-
`ing. In reviewing these markets Applicant has deter-
`mined that the large area dictates projection systems.
`either front or rear projection, that the high resolution
`requires integrated drivers and that projection systems
`do not require either transparent substrates or large
`display sizes.
`,
`It. therefore, would be desirable to provide an active
`matrix reflective projection system having high resolu-
`tion, integrated drivers and manufactured with conven-
`tional wafer fabrication techniques.
`SUMMARY OF INVENTION
`
`The disadvantages of the prior art displays and tech-
`niques are overcome in accordance with the present
`invention by providing an improved active matrix re-
`flective image plane module and projection system uti-
`lizing a conventional wafer.
`The reflective image plane module includes a wafer
`based active matrix coupled to a light directing and
`projecting structure utilizing two focal
`images. A
`source of light is directed to the reflective image plane
`module to the wafer based active matrix from a first
`image plane. The wafer based active matrix imparts or
`encodes information onto a light beam reflected there-
`from through a second image plane. The reflective
`image plane module light projecting structure projects
`the reflected beam for viewing. such as through one or
`more lens.
`The active matrix reflective projection system can be
`a monochrome projector including a reflective image
`plane module or can be a full color system including
`three reflective image plane modules. Each color reflec-
`tive image plane module operates on a single color
`component, red. green or blue. which then are com-
`bined on a screen or before projecting on the screen to
`form the full color projection image.
`The wafer based active matrix includes a specular
`reflective back surface and an LC or similar characteris-
`tic material
`formed thereon which is electronically
`altered to impart or encode the information to the light
`
`13
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`5,108,172
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`4
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
`3
`beam reflected therefrom. The LC material preferably
`is a solid light modulating material having bodies of LC
`material suspended in the solid material.
`The reflective image plane module light directing and
`projecting structure is formed from a mirror or mirror
`portion which directs the light or light component to
`the wafer based active matrix which reflects an encoded
`light beam therefrom and which projects the reflected
`light to be viewed.
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIGS. 1-15 describe the embodiments disclosed in
`parent application. Ser. No. 392,746.
`FIG. I is a diagrammatic view of a prior art light
`transmissive projector system;
`FIGS. 2A. 28 and 2C are diagrammatic top. front
`and side views of one reflective image plane module
`embodiment of the parent application:
`FIGS. 3A, SB and 3C are diagrammatic top. front
`and side views of a second reflective image plane mod-
`ule embodiment of the parent application:
`FIGS. 4A. 4B and 4C are partial diagrammatic side
`views of embodiments of projection surfaces for the
`reflective image plane module of FIGS. 3A-3C:
`FIGS. 5A. SB and 5C are diagrammatic top, front
`and side views of another reflective image plane module
`embodiment of the parent application:
`FIGS. 6A, 6B and 6C are diagrammatic top, front
`and side views of a funher reflective image plane mod-
`ule embodiment of the parent application;
`FIGS. 7A. 7B and 7C are diagrammatic top. front
`and side views of yet another reflective image plane
`module embodiment of the parent application;
`FIGS. 8A, SB and 8C are diagrammatic top. front
`and side views of a still further reflective image plane
`module embodiment of the parent application;
`FIG. 9 is a diagrammatic side view of one projection
`system embodiment of the parent application:
`FIG. to is a diagrammatic side view of a second
`projection system embodiment of the parent applica-
`tton;
`
`FIG. II is a diagrammatic side view of a further
`projection system embodiment of the parent applica-
`tton:
`
`FIG. 12 is a diagrammatic side view of another pro-
`jection system embodiment of the parent application;
`FIG. 13 is a perspective diagrammatic view of a still
`further projection system embodiment of the parent
`application;
`FIG. 14A. 148 and MC are diagrammatic top, front
`and side views of the projection system of FIG. 13;
`FIG. 15 is a diagrammatic side view of yet another
`projection system embodiment of the parent applica-
`tton;
`FIGS. 16-18 are directed to embodiments of the
`present invention;
`FIG. 16 is a diagrammatic view of one reflective
`image plane module and projection system embodiment
`of the present invention;
`FIG. 17 is a diagrammatic view of a second reflective
`image plane module embodiment of the present inven-
`tion; and
`FIG. 18 is a diagrammatic view of a second projec-
`tion system of the present invention incorporating three
`reflective image plane modules.
`
`FIGS. 1-15 describe the embodiments of the parent
`5 application, Ser. No. 392.746.
`Referring to FIG. I, a prior art light transmissive
`projection system IO is illustrated. A light source 12
`provides light to a lens or lens system 14. which directs
`the light to a transmissive LCD 16. A video or com-
`lO puter signal source (not illustrated) is coupled by a line
`18 to a video drive circuit 20. The video drive circuit 20
`operates on the signal coupled thereto and generates the
`required drive signals coupled over a line 22 to the
`LCD 16. Typically the drive signals will be the audio,
`15 red video. blue video, green video. vertical sync, hori-
`zontal sync, reset and pixel clock signals. The drive
`signals cause the pixels of the LCD 16 to block or trans-
`mit light to impart the required information onto the
`light transmitted through the LCD 16 to a lens or lens
`20 system 24 which projects the composite color picture
`onto the screen 26. A monochrome projection system
`would operate in the same manner with only one video
`light component. rather than the separate blue, green
`and red video signals.
`One prior art transmissive projection system has been
`developed by Seiko Epson Corp. and utilizes three
`separate LCD panels, one for each of the blue, green
`and red video signals. The signals then are combined by
`a dichroic prism prior to projecting onto the screen.
`30 These transmissive projection systems suffer from a
`number of problems. One significant problem is caused
`by the construction required by the LC material. The
`LCD panels include a polarizer on each side of the LC
`material. such as twisted nematic material, and are uti-
`35 lized as a shutter to absorb the light not to be transmit-
`ted. Both the polarizers and the LC material absorb
`light which generates heat, which is deleterious to the
`LCD panel. Further, because of the two polarizers, and
`the LC material utilized. only about fifteen per cent or
`40 less of the light directed to the LCD panel is transmitted
`therethrough for projection to the screen. The devices
`exhibit low brightness because of the amount of light
`absorbed.
`
`25
`
`the' resolution of the transmissive panels,
`Further,
`45 typically based upon amorphous silicon deposited ac-
`tive matrix devices, is nm as great as that which could
`be achieved if crystalline based technology was utilized.
`The pixel density can be made greater by placing the
`pixel drain pads centered over row and column lines in
`50 crystalline wafer based devices. Amorphous silicon
`devices have to leave spaces between pixels for the row
`and column lines and hence cannot be packed as densely
`without seriously decreasing the yield.
`As mentioned above, deposited amorphous silicon
`55 devices have a much greater number of LCD panel
`interconnects. This decreases reliability and increases
`cost. These devices are also designed as large area de-
`vices which again decreases yield and increases costs.
`If polysilicon is utilized to decrease the number of
`60 interconnects, other problems occur since the polysili-
`con transistors are leaky. Therefore,
`typically these
`LCD devices utilize two transistors in series at each
`pixel, which again decreases reliability and increases
`costs.
`
`65
`
`Referring to FIGS. 2A. 2B and 2C. top. front and side
`views of a first embodiment of a reflective image plane
`module of the parent application is designated generally
`by the reference character 30. A light source 32, such as
`
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`5
`a bulb and a reflector, provides a source of light. The
`light is columnated by a lens 34 and condensed or fo«
`cused by a lens 36 to the reflective image plane module
`30. The reflective image plane module 30 is further
`described in Ser. No. 392.747, entitled “REFLECTIVE
`IMAGE PLANE MODULE". filed Aug. ll. 1989.
`now U.S. Pat. No. 5.024.524 and incorporated herein by
`reference.
`The reflective image plane module 30 includes a first
`mirrored wall 40 which has an aperture 42 through
`which the light passes and impinges on a back wall 44 of '
`the reflective image plane module 30. The back wall 44
`has attached thereto or is formed of a wafer based active
`matrix 46. The light has the information impaned to or
`encoded on it by the wafer based active matrix 46 as it
`is reflected from the wafer based active matrix 46. One
`specific example of the wafer based active matrix is
`further described
`in Ser. No.
`392.859.
`entitled
`“WAFER BASED ACTIVE MATRIX". filed Aug.
`11, I989 and incorporated herein by reference.
`, The wafer based active matrix 46 is a wafer based
`active matrix having a specular reflective back surface
`to reflect light therefrom. The wafer based active ma~
`trix is covered by an LCD or similar characteristic
`material, such as an electrophoretic material. One pref-
`erable LCD material is a solid light modulating material
`having bodies of LC material suspended therein. Exam-
`ples of such LCD materials are described in U.S. Pat.
`Nos. 4.435.047 and 4,688,900, which are incorporated
`herein by reference. This LCD material requires higher
`operating voltage on the order of 12 volts RMS. which
`is far more suited to crystalline active matrix devices
`than to polysilicon or amorphous silicon devices. The
`crystalline devices also have greater current carrying
`capacity and faster switching speeds.
`The light reflected from the wafer based active ma-
`trix 46 is reflected by a mirror back surface 48 of the
`wall 40. The reflected light from the reflective image
`plane module 30 is directed to a projection lens 50.
`which lens or lens system can be a fixed or zoom type
`lens. and projected by the lens 50 to be viewed, typi~
`cally on a screen (not illustrated). The reflective image
`plane module 30 as described can be utilized as a mono-
`chrome projection system or can be combined as will be 45
`described hereinafter to form a unit of a full color pro-
`jection system. The reflective image plane module‘ 30
`generally only includes the light directing and reflect-
`ing structures formed by the elements 40. 42, 44 (includ~
`ing the wafer based active matrix 46) and 48. The reflec-
`tive image plane module 30 can, however, include the
`light 32 and other light directing elements 34, 36 and 50
`if desired.
`A second embodiment of a reflective image plane
`module of the parent application is best illustrated in
`FIGS. 3A-3C, designated generally by the reference
`character 52. The same or equivalent elements in this or
`succeeding embodiments will utilize the same numerals
`as previously described with respect to the reflective
`image plane module 30. The reflective image plane
`module 52 functions substantially the same as the reflec-
`tive image plane module 30, as illustrated in FIG. 3C.
`The reflective image plane module 52 replaces the mir-
`ror 48 with a prism 56. The prism 56 includes a projec-
`tion 58 formed in a first wall 60 thereof.
`The projection 58 includes a light receiving surface
`62, through which the light is focused. As before, the
`light is acted upon and reflected by the wafer based
`
`6
`active matrix 46 and again reflected by an inside surface
`64 of the wall 60 to the lens 50.
`The projection 58 and the surface 62 form another
`optical element of the reflective image plane module 52.
`As illustrated in FIGS. 4A-4C. the surface 62 can be
`flat. can be a convex surface 62' or can be a concave
`surface 62" as desired. The shape of the surface 62 is
`chose to widen, narrow and/or direct the light beam.
`Preferably.
`the reflective image plane module 52 is
`injection molded as an integral unit. Again, the reflec-
`tive image plane module 52 generally only includes the
`light directing and reflecting structures. here the prism
`56 and the wafer based active matrix 46.
`_ A third embodiment of a reflective image plane mod-
`ule of the parent application is best illustrated in FIGS.
`SA-SC and is designated generally by the reference
`numeral 66. The focused light beam utilizing the lens 34
`and 36 would collect the most light, but the lens system
`encompasses a fairly large amount of space. The reflec-
`tive image plane module 66 provides a very compact
`unit by eliminating the lens 34 and 36. A light source 68,
`such as a bulb. is mounted directly into the aperture 42
`of the wall 40 of the reflective image plane module 66,
`which otherwise operates the same as the reflective
`image plane module 30. The light is reflected from the
`wafer based active matrix 46 to the mirror surface 48 to
`the lens 50. This is not the most energy efficient embodi-
`ment and if utilized in a color system, the light from the
`bulb 68 would be passed through the appropriate filter
`to provide the red, green or blue color component.
`Again. the light 68 and lens 50 generally would not
`form part of the reflective image plane module 66.
`A further embodiment of a reflective image plane
`module of the parent application is best illustrated in
`FIGS. 6A-6C and is designated generally by the refer-
`ence numeral 70. The reflective image plane module 70
`is somewhat of a compromise between the reflective
`image plane module 30 and 66. A light source 72 is
`coupled into a fiber optic light guide or tube 74, which
`directs the light into the reflective image plane module
`70 through the aperture 42, where it is acted upon like
`the reflective image plane module 30. The guide 74
`gathers more light than utilizing the bulb 68, but encom-
`passes more space than the bulb 68. The light guide 74
`is more flexible and occupies less space than the lens
`system 34, 36.
`The bulb 68 can be utilized with the prism type reflec-
`tive image plane module 52. as best illustrated in FIGS.
`7A—7C, forming another reflective image plane module
`embodiment of the parent application which is desig-
`nated generally by the reference numeral 76. The opera-
`tion of the reflective image plane module 76 is generally
`the same as the reflective image plane module 52, once
`the light is introduced to the reflective image plane
`module 76.
`'
`
`The light guide 74 also can be utilized with the prism
`type reflective image plane module 52, as best illus-
`trated in FIGS. SA-SC, forming a further reflective
`image plane module embodiment of the parent applica-
`tion which is designated generally by the reference
`numeral 78. Again, the operation of the reflective image
`plane module 78 is generally the same as the reflective
`image plane module 52, once the light is introduced to
`the reflective image plane module 78.
`Each of the above reflective image plane modules can
`be utilized as part of a monochrome projection system
`or can form one reflective image plane module of a
`three lens color projection system embodiment of the
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`7
`parent application. for example. as illustrated in FIG. 9
`and which is designated generally by the reference
`character 80. The projection system 80 includes a light
`source 82. such as a bulb and reflector. from which light
`is directed through a columnating lens or lens system 84
`to form a beam of light 86. The light 86 includes all
`three light components red. blue and green (hereinafter
`R. B and G).
`The beam 86 is directed to a B dichroic mirror 88.
`The B light component 90 is reflected from the mirror
`88 to a B reflective image plane module 92. The B re-
`flective image plane module 92 can be any of the above-
`described reflective image plane modules 30. 52. 70 and
`78. The encoded B light 94 is reflected from the 8 re-
`flective image plane module 92 to a lens 96 and pro-
`jected by the lens 96. to a screen 98. where it is com-
`bined with the other components to form a color image.
`A light beam 86’ passes through the mirror 88 with
`the G & R light components therein. The light beam 86’
`is directed to a G dichroic mirror 100. The G light
`component 102 is reflected from the mirror 100 to a G
`reflective image lane module 104. The encoded G light
`106 is reflected from the G reflective image plane mod-
`ule 104 to a lens 108 and projected by the lens 108 to the
`screen 98.
`A light beam 86" passes through the mirror 100 with
`only the R component therein. The beam 86" is directed
`to a mirror 110 and reflected therefrom to a R reflective
`image plane module 112. The encoded R light 114 is
`reflected from the R reflective image plane module 112
`to a lens 116 and projected by the lens 116 to the screen
`98. The information encoding is provided by an elec-
`tronic interface 118 coupled to the reflective image
`plane modules 92. 104 and 112.
`A second three lens projection system embodiment of 35
`the parent application is best illustrated in FIG. 10 and
`is designated generally by the reference numeral 120.
`The same or equivalent elements of the projection sys‘
`tem 120 and succeeding systems utilize the same refer-
`ence numerals as the system 80. The projection system
`120 again has three reflective image plane modules 92.
`104 and 112 which impart the information into the three
`B. G and R light components projected onto the screen
`98.
`The projection system 120 again has a single light
`source. light 122; however. the B, G. and R light com-
`ponents are derived by utilizing respective B. G, and R
`light filters 124. 126 and 128. The B light is coupled into
`a B filter optic light guide 130 by a condenser lens 132
`and directed to the B reflective image plane module 92.
`In a like manner, the G light is coupled with a G light
`guide 134 by a condenser lens 136 and directed to the G
`reflective image plane module 104. The R light is cou-
`pled into an R light guide 138 by a condenser lens 140
`and directed to the R reflective image plane module
`112. The operation of the projection system 120 is oth-
`erwise identical to the operation of system 80.
`An embodiment of a single lens projection system is
`best illustrated in FIG. 11 and is generally designated by
`the reference character 142. The color projection sys-
`tem 142 again includes the three color reflective image
`plane modules 92. 104 and 112. but each reflective
`image plane module now includes its own light source
`144. 146 and 148. The separate light sources again re-
`quire the respective B. G and R filters 124. 126 and 128
`to provide the B. G and R. light components. The en-
`coded B. G and R light components are each directed to
`a respective dichroic prism section of a conventional
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`dichroic combining prism 150. The combining prism
`150 combines the three B. G and R light components
`and outputs a single combined and encoded color signal
`152, which is directed to a lens or lens system 154 and
`then is projected onto the screen 98.
`A non-complex. three lens projection system com-
`bines elements from the other projection systems. and is
`best illustrated in FIG. 12 and is designated generally by
`the reference character 156. The projection system 156
`includes the three separate light sources 144, 146 and
`148 and the respective B, G and R filters 124. 126 and
`128. which direct the light components to the respective
`reflective image plane modules 92, 104 and 112. The
`separate output components 94. 106. 114 then are di-
`rected to the respective lens 96, 108 and 116 for projec-
`tion and combining onto the screen 98.
`Another single lens projection system embodiment of
`the parent application is best
`illustrated in; FIGS.
`13-14C and is designated generally by the reference
`character 158. The output of the three B, G and R
`reflective image plane modules 92, 104 and 112 are
`combined in the combining prism 150 and output on the
`single signal 152 to the projector lens 154. A single light
`source 160 directs light to the B dichroic mirror 88
`which directs the B light component to the B reflective
`image plane module 92. The G dichroic mirror 100
`directs the G light component to a mirror 162 which
`then directs the G light component to the G reflective
`image plane module 104. The R light component is
`directed to the R reflective image plane module 112 by
`the mirror 110.
`Referring now to FIG. 15 an embodiment of a single
`imaging. single lens projection system of the parent
`application is best illustrated and is designated generally
`by the reference numeral 164. A light source 166, of any
`of the above referenced types, provides light to a multi-
`color reflective image plane module 168. In this config-
`uration. only one reflective image plane module is uti-
`lized with one wafer based active matrix; however. the
`wafer based active matrix includes a mosaic or other
`type of color filter array integral therewith. This config-
`uration would not currently be the most desirable, be-
`cause three monochrome reflective image plane mod-
`ules would triple the resolution on the screen 98 and
`would absorb much less heat than the single reflective
`image plane module 168.
`Referring now to FIGS. 16—18, the embodiments of
`the present invention are illustrated.
`A first projection system embodiment of the present
`invention is illustrated in FIG. 16, designated generally
`by the reference numeral 170. The projection system
`170 includes a light source 172, which preferably in-
`.cludes a reflector 174. A light beam 176 is directed
`through an optional heat absorbing glass plate 178 to a
`condenser lens or lens combination 180.
`The lens 180 focuses the light beam 176 through an
`optional color filter 182 onto a mirror or structure 184
`having a mirror portion 186. The mirror portion 186 is
`at a first focal point or plane of the light beam 176. The
`mirror portion 186 is adjacent a free edge 188 or open-
`ing in the mirror structure 184. The color filter 182
`would not be utilized in a monochrome system.
`The reflected light beam 176 then is directed to a
`plane convex lens (PCX) 190 or double convex lens (as
`illustrated), which directs the beam 176 to a wafer based
`active matrix 192. The wafer based active matrix 192
`preferably is the same as the wafer based active matrix
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`XLNX—100