JP2002540447A - Method and apparatus for illuminating a display - Google Patents

Abstract

(57) Abstract: An apparatus for generating colored light and an image forming apparatus including such an apparatus are disclosed. The apparatus includes a switching light directing device configured to receive light, and a first control circuit connected to the switchable light directing device. The first control circuit supplies a control signal to the switchable light directing device. When the switchable light directing device receives the control signal, the light directing device directs a first portion of the incident light to a first region of the surface. Further, the light directing device directs a second portion of the light incident thereon to a second region of the surface and a third portion of the incident light to a third region of the surface. The second region is located between the first and second regions of the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] This patent application is a US provisional patent application Ser. No. 60 / 125,92, filed Mar. 23, 1999, entitled "METHOD AND APPARATUS FOR ILLUMINAING A DISPLAY".
No. 4, "DEVICE FOR PRODUCING COLOURED LIGHT AND IMAGE GENERATION APPARAT
US Provisional Patent Application No. 60 / 127,898, filed April 5, 1999, entitled "US INCLUDING SUCH A DEVICE," and "DEVICE FOR PRODUCING COLOURE
US Provisional Patent Application No. 60 / 157,796, filed October 5, 1999, entitled "D LIGHT AND IMAGE GENERATING APPARATUS INCLUDING SUCH A DEVICE".
Claim priority to the issue.

FIELD OF THE INVENTION [0002] The present invention relates generally to methods and apparatus for illuminating an image display, and more particularly to methods and apparatus for illuminating a sequential color image display.

Description of the Related Art A sequential color display uses a display screen to display a series of single color frames corresponding to the red, green and blue colors of a final single color image. A typical sequential color display may take the form of a reflective LCD macro display. The image generated on the display is such that red light illuminates the red monochrome frame of the final monochrome image, green light illuminates the green frame of the final monochrome image, and blue light illuminates the final monochrome image. It is continuously illuminated by red, green and blue light to illuminate a blue frame. Subsequent components of the monochrome image are similarly illuminated. Switching from one image to the next image is performed at high speed, so that the viewer can effectively view the full-color image.

[0004] Continuous illumination of an image frame with red, green and blue light is typically achieved using a white light source and a rotating color wheel. Such wheels are prone to mechanical malfunctions. Alternatively, continuous illumination of the image frame with red, green and blue light is typically achieved using a white light source and a solid state device such as a liquid crystal polarization switch. However, this alternative form of technology also has drawbacks. More specifically, solid-state technologies that use solid-state devices such as liquid crystal polarization switches operate only with polarized light. Thus, at least half of the available light for illuminating a particular monochrome frame is quickly lost. An even more significant problem with mechanical and solid state technologies for illuminating sequential color displays is that one-third of the available white light is used to collectively illuminate the red, green and blue monochromatic frames of the image. Only one is used. In other words, when the red monochrome frame of the final image is displayed, only the red light is used to illuminate, while the green and blue components of the white light source are filtered and not used.

SUMMARY OF THE INVENTION The present invention relates to an apparatus for generating colored light, and to an image generating apparatus including such an apparatus. The apparatus comprises a switchable optical device configured to receive light and a first control circuit connected to the switchable light directing device. The first control circuit provides a control signal to the switchable light directing device. In response to the switchable light directing device receiving the control signal, the switchable light directing device directs a first portion of the received light to a first region of a plane. Further, the switchable photo-orientation device directs the second and third portions of the received light to second and third regions of the plane, respectively. The second region is located between the first and third regions of the plane.

In one embodiment, a switchable photo-orientation device includes first, second and third electrically switchable holographic optical elements, each element switching between an active state and an inactive state. A first group of electrically switchable holographic optical elements that are selectively switchable. The first, second, and third electrically switchable holographic optical elements are each configured to diffract incident light when operating in an active state, and the first, second, and third electrically switchable holographic optical elements are each configured to diffract incident light. Each of the switchable holographic optical elements transmits the incident light substantially unchanged when operating in an inactive state. In this embodiment, the first, second and third electrically switchable holographic optical elements are each switched to an active or inactive state by a first control circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a system including a light transmission type device for generating colored light and a device for forming an image. FIG. 1 shows an image display device 112 including a light source 100 that generates white light 102, a collimating element 104, a switchable optical system 108, and an image display surface 114 composed of an array of pixels that display monochromatic data. The control circuit 116 and the lighting control circuit 118 are shown.

The collimating element 104 receives the white light 102 generated by the light source 100. Next, the collimating element 104 collimates the white light 102 into a collimated white light 106. The switchable optical system 108 receives the collimated white light 106 and generates at least three different bandwidths of illumination light in response thereto. In the preferred embodiment, switchable optics 108 includes red (R) and green (G)
, Blue (B) bandwidth illumination light. The switchable optical system 108 generates shaped, filtered, condensed and / or collimated white light 106 to generate illumination light. Further, the switchable optical system 208 selectively directs the illumination light on a partial surface of the image display surface.

The switchable optical system 108 simultaneously illuminates at least three different partial surface areas of the image display surface 114 with respective illumination lights R, G, B. It is desirable that the three partial surfaces have the same size. With reference to FIG. 1, the switchable optical system 108 is configured to divide each of three adjacent partial surfaces 114A-114C into one illumination light R, G
, B illuminate the entire surface 114 simultaneously. The switchable optics 108 or any of the switchable optics described below may not illuminate the entire surface 114 with three illumination lights simultaneously. Switchable optics 108 can simultaneously illuminate three sub-surfaces smaller than that shown in FIG. For example, switchable optics 108 or any of the other switchable optics described below may simultaneously illuminate each of only three pixels of the display surface with each of the three illumination lights. Further, the switching optical system 10
8 or any other switchable optics described below can simultaneously illuminate each of the three pixels of the display surface with each of the three illumination lights.

The display surface 114 displays single-color data of a single-color image according to a signal generated by the image control circuit 116. Each single color image is composed of three single color frames (ie, a red single color frame, a green single color frame, and a blue single color frame). Referring to FIG. 1, each monochrome image is displayed in a three-step cycle.
In each cycle, a portion of each monochrome frame is represented by a partial surface 114A.
And 114B and 114C. For example, in the first cycle, partial surface 114A displays the monochromatic component of the upper red frame, and partial surface 114A.
B and 114C display the monochromatic components of the center and lower green and blue frames, respectively. In the second cycle, partial surface 114A displays the monochromatic components of the upper green frame, and partial surfaces 114B and 114C display the monochromatic components of the center and lower blue and red frames, respectively. In the third or final cycle, partial surface 114A displays the monochromatic component of the upper blue frame and partial surface 114A.
B and 114C display the monochromatic components of the center and bottom red and blue frames, respectively.

The illumination control circuit 118 is connected to the image control circuit 116 and the switchable optical system 108. The switchable optical system 108, which operates according to the instructions of the control circuit 118, selectively directs each of the illumination light R, G, and B to one of the partial surfaces 114A-114C.
The illumination control circuit 118 is connected to the image control circuit 116 and operates in synchronization therewith. In the embodiment shown in FIG. 1, the switchable optical system 108 operates in a three-stage cycle. In the first cycle, the switchable optics 108 receives one or more control signals from the control circuit 118 and directs the illumination light R to the partial surface 114A accordingly, and as described above, the partial surface 114A Displays a red single color frame. Switchable optics 108 also provides illumination light G and B with partial surfaces 114B and 114C, respectively.
And in the first cycle, the partial surfaces 114B and 114C display portions of the central and lower green and blue monochromatic frames, respectively. In the second cycle,
The switchable optics 108 receives one or more second control signals and directs the illumination light G to the partial surface 114A accordingly, which displays the green monochromatic frame of the upper portion, as described above. I do. Switchable optics 108 also directs illuminating light B and R to partial surfaces 114B and 114C, respectively, and in a second cycle, partial surfaces 114B and 114C display central and lower blue and red frames, respectively. . In the third cycle, switchable optics 108 receives one or more third control signals and directs illumination light B to partial surface 114A accordingly, with partial surface 114A having an upper blue Display a single color frame. Switchable optics 108 also directs illumination light R and G to partial surfaces 114B and 114C, respectively, and in a third cycle, partial surfaces 114B and 114C display central and top red and green monochromatic frames, respectively. I do.

The second stage of the three stage cycle is shown in FIG. Partial surface 114A
Is illuminated with green illumination light G when displays the single color component of the upper green frame. When the partial surface 114B displays the monochromatic component of the center blue frame, it is illuminated with the blue illumination light B. When the partial surface 114C displays the monochromatic component of the lower red frame, it is illuminated with the red illumination light R. If the monochromatic components displayed in the first and third stages are similarly illuminated, and if the switching speed of the three stages is fast enough, the observer will see the illuminated part finally as an integrated image. It is possible.

When the three-step cycle ends, the image control circuit 116 starts the next three-step cycle for the next image. The present invention is not limited to displaying a monochrome image in a three-step cycle. According to the present invention, it is possible to simultaneously display three types of each single color frame on three types of pixels on the image display surface. In another embodiment of the present invention, when a monochrome image is illuminated with illumination light R, G, B, the monochrome image moves down the display surface. Further, the present invention can simultaneously display three pixels each consisting of a single color frame on three pixels on the image display surface. In this embodiment, when a monochrome image is illuminated with the illumination lights R, G, and B, the image can be scrolled horizontally and downward on the image display surface.

FIGS. 7A to 7C are front views of the display surface 114 of FIG. 7A-7C illustrate how the switchable optical system 108 preferably illuminates each single color component of the final image. In FIG. 7A, when subsection 114A is displayed to be a red monochromatic component of the final image of the partial surface, subsection 114A glows red. Subsection 1
Subsection 114B glows green when 14B displays the final image of that portion to be a green monochromatic light component. When subsection 114C displays such that the final image in that portion is a blue monochromatic component, subsection 114C glows blue. 7B and 7
C is a small section 114A-114C when the monochromatic component of the final image of the partial surface is transferred.
Illumination is shown.

FIG. 2 shows another embodiment of a system having a light transmitting device for generating colored light and an image generating device. The embodiment of FIG. 2 includes a white light source 100 that generates white light 102, a collimating element 104, a filter 202, a switchable optical system 206, an image display device 112 including a display surface 114, an image processing circuit 116, , An illumination control circuit 118. The same reference numbers in each figure indicate similar elements.

The collimating element 104 shown in FIG. 2 collimates the white light 100 into a collimated white light 106. The collimated white light 106 reaches a filter 202 where it is spatially separated into at least three output lights 204R and 204G, 204B of different bandwidths. In the embodiment shown in FIG. 2, output light 204R is the red bandwidth component of collimated white light 106, and output light 204G is the green bandwidth component of collimated white light 106. Light 204B is the blue bandwidth component of collimated white light 106.

The switchable optical system 208 shapes, converges, and / or corrects the output lights 204R, 204G, and 204B to generate illumination lights R, G, and B, respectively. Further, the switchable optical system 208 selectively directs the illumination light on the surface of the image display surface. The image display device 112 displays a monochromatic image in the same manner as described with reference to FIG. The image control circuit 118 controls the switchable optical system 208 in synchronization with the monochromatic component displayed on the display surface 114.

The switchable optical system 208 operates in a three-stage cycle. In the first stage of this three-stage cycle, switchable optics 208 directs illumination light R, G, and B onto display surfaces 114A, 114B, and 114C, respectively, and subsurfaces 114A and 11C.
4B, 114C display the preferred monochrome components of the final image. In the second stage of this three-stage cycle, switchable optics 208 directs illumination light R, G, and B to image portion surfaces 114C and 114A, 114B, respectively, and these image portion surfaces 114
C and 114A, 114B represent the preferred monochrome components of the final image. In the third stage of the three-stage cycle, switchable optics 208 directs illumination light R, G, and B to partial surfaces 114B, 114C, and 114A, respectively, and connects these partial surfaces 11A and 11B.
4B and 114C, 114A display the preferred monochrome components of the final image. As shown in FIGS. 1 and 2, when the display surface 114 displays the final image, all or substantially all of the collimated white light 106 is used to illuminate the display surface 114.

FIG. 1 shows another embodiment of a system having a light transmission type device for generating colored light and an image forming apparatus. FIG. 3 shows a light source 100, a collimating element 104,
A switching optical system 308, an image display device 112 having a display surface 114, an image control circuit 116, and an illumination control circuit 118 are shown. 1 and 3 are the same except for the switchable optical system 308. A significant difference between the systems of FIGS. 1 and 3 relates to the intensity of the illumination light R, G, B generated by the switchable optical system 308. Unlike the embodiment shown in FIGS. 1 and 2, the switchable optical system 308 shown in FIG.
Always illuminates the entire display surface 114 with substantially less light than all available collimated white light 106.

Each of the embodiments shown in FIGS. 1 to 3 includes a transmission type switching optical system. In the present invention, a reflection-type switching optical system can be used. In the embodiment of FIG. 4, the switchable optical system 108 of the embodiment of FIG. Indicates what was done. Except for this reflection characteristic, the switchable optical system 408 operates substantially the same as the switchable optical system 108 shown in FIG.

As shown in FIG. 1, in the switching optical system 108, the illumination lights R, G, and B are emitted from the surface opposite to the surface on which the collimated white light 106 is incident.
In contrast, the reflective switching optical system 408 emits illumination light R-G from the same surface on which the collimated white light 106 is incident. FIG. 5 shows that the switchable optical system 208 of FIG. 2 has been changed to a switchable optical system 508 and that the image display system 112 has been relocated to a position where the reflection characteristics of the switchable optical system 508 can be used effectively.
The switching type optical system 508 is a reflection type optical system, and is a switching type optical system 2 shown in FIG.
08 is a transmission system. FIG. 6 shows a transmission type switching optical system 3 of the system of FIG.
Reference numeral 08 is a reflection type switchable optical system 608. Also, like the optical system shown in FIG. 3, the switchable optical system 608 shown in FIG. 6 illuminates the surface 114 with substantially less light than substantially all of the collimated white light 106.

FIGS. 7A-7C illustrate one mode in which the monochrome components of the final image are displayed and illuminated on image surface 114. As shown, the display surface 114 is divided into three regions of equal size, each of which periodically and sequentially represents red, green, and blue when a preferred monochromatic component is displayed thereon. Illuminated by illumination light. The present invention is not limited to this. FIG. 8 shows a front view of the display surface 114 divided into six of the partial surfaces 114A to 114F. In this embodiment, the partial surfaces 114A and 114B are sequentially displayed in a single color that is the red, blue, and green portions of the final image on each partial surface, and the partial surfaces 114B and 114E are finalized in their respective regions. The image is displayed periodically and sequentially in a single color that is green, red, and blue portions of the image.
14A is periodically displayed sequentially in a single color that is the blue, green, and red portions of the final image in each region. Further, when the partial surfaces 114A and 114D display a monochromatic red component, the partial surfaces 114B and 114E display a monochromatic green component, and the subsurfaces 114C and 114F display a monochromatic blue component, respectively. As shown in FIG. 8, in order to illuminate the monochromatic components of the final image displayed on the partial surfaces 114A-114F, the switchable optics of FIGS. 1-6 provide red, green, and blue illumination. It must be modified to generate two separate groups of light. In this embodiment, the first group of red, green, and blue illumination light respectively comprises the partial surface 11
A second group of red, green, and blue illumination light, selectively oriented at 4A-114C, is selectively oriented at partial surfaces 114D-114F, respectively. Therefore,
The modified switchable optical system directs the red illumination light to the two partial surfaces, which then display the red monochromatic component of the final image, and directs the green illumination light to display the green monochromatic component image.
And the blue illumination light is directed to the two partial surfaces, which then display a blue monochromatic component image. The modified switchable optical system directs the first group of red, green, and blue illumination light to the partial surfaces 14A-14C, respectively, in synchronization with the red, green, and blue monochromatic components of the final image on the display. It operates periodically as follows. Similarly, the modified switchable optics allows the second group of red, green, and blue illumination light to illuminate the partial surface 114D-114F in synchronization with the red, green, and blue monochromatic components of the final image on the display.
Periodically.

9A-9F show front views of an image display surface 114 operating according to another embodiment. In this embodiment, the front surface 114 has six partial surfaces 114A-1 of the same size.
It is divided into 14F. The display surface 114 can be further divided into regions, each of which occupies the street of a pixel. However, the invention is shown with an image display surface of the same size but divided into six separate partial surfaces.

Although the display surface described above operates in three stages to form a complete image, FIG. 9A
-The surface 114 shown in Fig. 9F operates in six steps to fully display the final monochrome image. Each of the partial surfaces 114A-114F is displayed in a single color that is the red, green, and blue portions of the final image in those portions. However, the display of the red, blue, and green portions does not occur sequentially and periodically as described above. In this embodiment, only three of the partial surfaces 114A-114F will always display the red, green, and blue portions of the final image. The display of the portion of the final image moves downward on the display surfaces 114A-114F as shown in FIGS. 9A-9F. FIG.
A shows the first stage of the six-stage cycle. In FIG. 9A, the partial surfaces 14A-14C are each displayed in a single color on each of the partial surfaces, which are the red, green, and blue portions of the final image, respectively. As shown in FIG. 9B, in the second phase of the six-phase cycle, the partial surfaces 114B-114D are each displayed in a single color, the red, green, and blue portions of the final image in those portions. . FIG. 9C
In the third phase of the six-phase cycle, as shown in FIG.
Each of -114E is displayed in a single color that is the red, green, and blue components of the final image in those portions. In the fourth stage, shown in FIG. 9D, the partial surface 14D-1
4F are each displayed in a single color that is the red, green, and blue components of the final image in those portions. In FIG. 9E, the partial surfaces 114E and 114F, 114A are each displayed in a single color that is the red, green, and blue components of the final image at those portions. As shown in FIG. 9F, in the last stage, the partial surfaces 114F and 114A, 114B respectively have the red and green of the final image in their parts,
The blue component is displayed in a single color.

FIGS. 9A-9F show snapshots of the display surface 114 at each stage of the six-stage cycle. Switchable optics 108 and 208,3, to illuminate only the partial surfaces 114A-114F displaying the monochromatic components of the final image at any time with suitable illumination light.
08, 408, 508, 608 (above) can be changed. Specifically, the modified switchable optical system of this embodiment operates in six stages. In the first stage of the six-stage cycle, the switchable optics emits red, green and blue illumination light, respectively, on the partial surface 11.
4A-114C and the partial surfaces 114A-11 as shown in FIG. 9A.
4C respectively display the red, green and blue monochromatic components of the final image. In the second stage, the modified switched optics emits red, green and blue illumination light respectively to the partial surface 11.
4B and 114C, 114D, and a partial surface 1 as shown in FIG. 9B.
14B and 114C and 114D respectively display the red, green and blue monochromatic components of the final image. In the third stage of this six-stage cycle, the modified switched optics directs the red, green, and blue illumination light to partial surfaces 114C and 114D, 114E, respectively, as shown in FIG. 9C. Partial surfaces 114C and 114D, 114E
Respectively display the red, green and blue monochromatic components of the final image. In the fourth stage of this six-stage cycle, the modified switchable optics directs red, green, and blue illumination light to partial surfaces 114D and 114E, 114F, respectively, and is shown in FIG. 9D. Thus, partial surfaces 114D and 114E, 114F respectively represent the red, green, and blue monochromatic components of the final image. In the fifth stage of this six-stage cycle, the modified switchable optics directs red, green, and blue illumination light to partial surfaces 114E and 114F, 114A, respectively, as shown in FIG. 9E. Partial surface 114E
And 114F and 114A respectively display the red, green and blue monochromatic components of the final image. In the last stage of the six-stage cycle, the modified switchable optics directs the red, green, and blue illumination light respectively, and as shown in FIG.
4F and 114A, 114B respectively display the red, green, and blue portions of the final image. Changed switchable optical system and switching of display surface, ie, repetition of operation (cyclin
g) allows the observer to see the final image efficiently without seeing the division between the partial surfaces 114A-114F.

FIGS. 10A to 10C show another embodiment using the filter 202 in the embodiments of FIGS. 2 and 5. FIG. In FIG. 10A, the filter 202 includes three dichroic filters 1002 and 1004, 1006 arranged sequentially along the optical path from the light source 100 (not shown in FIGS. 10A-10C). More specifically, the collimated white light 106 enters the filter 1002, and the red bandwidth component is reflected in the horizontal direction to become the output light 204R. Other components of the collimated white light 106 pass through the filter 1002 substantially unchanged. Filter 100
2 pass through filter 1004, the green bandwidth component is reflected laterally into green output light 204G, and the blue bandwidth component passes through substantially unchanged. The remaining blue bandwidth component of the collimated white light is
06 and is reflected laterally to become output light 204B.

The filter 202 shown in FIG. 10B is similar to the one shown in FIG. 10A. However, the collimated white light is incident on the two-color filter 108, this red bandwidth component is transmitted and becomes the output light 204R, and the remaining blue and green bandwidth components of the collimated white light are deflected to the side. Is done. Filters 1004 and 1006 reflect the green and blue bandwidth components of the light deflected by filter 1008, respectively, and output light 204G and 20G, respectively, as shown in FIG. 10A.
4B.

FIG. 10C shows a filter 202 that includes a two-color prism 1012 with a two-color layer at the interface, and a set of planar mirrors 1014 and 1016. Cross d
Nitto Optical of under the name of icroic Prism
A two-color prism manufactured by Japan can be used in FIG. 10C. Such prisms are typically manufactured from glass such as DK7,
It functions in the visible region of nm and has a reflectivity of 94% or more for polarized light incident at a normal angle. A prism having a high transmittance and relatively strong polarization of incident light can also be used. The prism 1012 is connected to the input surface 10 on which the collimated white light 106 is incident.
18 and three output surfaces 1020 and 1022,1024. The red bandwidth component of the collimated white light 106 is reflected and filtered at the prism interface, is deflected inward, and exits output surface 1020 as output light 204R. This light is then deflected 90 degrees by a mirror 1014 and travels to a switchable optical system. The green bandwidth component of the collimated white light 106 passes through the prism 112 substantially undeflected and exits the surface 1022 as output light 204G. The blue bandwidth component of the collimated white light 106 is deflected and filtered at the prism interface, reflected to one side, and exits the output surface 1024 as illumination light 204B. Next, 204B is deflected 90 degrees by mirror 1026.

As described above, the switching optical systems 108 and 208, 308, 408, 508,
608 can direct red, green, and blue illumination light to display surfaces 114A-114C. Typically, switchable optics 108 and 208, 308, 408, 508, 60
8 condenses the illumination light on the partial surface. Further, switching optical systems 108 and 308,
408, 608 may filter the collimated white light 106. Switchable optics can be formed based on solid state switch technology using ultrasonic optical materials and liquid crystals or opto-mechanical devices such as rotating prisms or mirrors or diffraction gratings. In a preferred embodiment, the switchable optics is based on electrically switchable holographic optics.

Accordingly, the switchable optics described above include an electrically switchable holographic optical element (ESHOE) system. This ESHOE is used to orient the illumination light as described above.
It has at least three groups of two electrically switchable holographic elements. The ESHOE system also filters the collimated white light 106 to generate red, green, and blue illumination light separately, or focuses the illumination light on a partial surface of the display surface 114. Further, the ESHOE system performs shaping and generation of light. However, the last function is preferably performed by conventional optics embedded in another glass or plastic independent of the ESHOE system. The collection of the illumination light on the partial surface of the image display can be performed using a conventional optical system.

FIG. 11 is a cross-sectional view of a switchable holographic optical element that can be used in an ESHOE system. The switchable holographic optical element of FIG. 11 includes a set of substantially transparent and electrically non-conductive layers 1102, a set of substantially transparent and electrically conductive layers 1104, and (1. (In an embodiment) a switchable holographic layer 1106 comprised of a polymer dispersed liquid crystal material. This liquid crystal material has the name `` Optical Filter Employing Holographic Optical Elements and Image Gene
No. 09 / 478,150, filed Jan. 5, 2000, which is incorporated herein by reference. In one embodiment, the substantially transparent, electrically non-conductive layer 1102 comprises glass and the substantially transparent, electrically conductive layer 1104 comprises indium tin oxide (ITO). . Although not shown, an anti-reflective coating is applied to selected surfaces of the switchable holographic optical element, including the surface of the ITO and the electrically conductive layer, to increase the overall transmission efficiency of the optical element and reduce stray light. Can be reduced. As shown in the embodiment of FIG. 11, all the layers 1102-1106 are arranged on the same axis 408 as a stack of hot cakes. Also, each layer can have flexibility.

The layers 1102-1106 can have a substantially thin cross-sectional width, resulting in an aggregate having a substantially thin cross-section. More specifically, a switchable holographic layer 1
106, 5 (although the exact width depends on the spectral bandwidth and the required diffraction efficiency)
１２12 μm, while the non-conductive glass layer 1102 has a cross-sectional width of 0 μm.
. It can be 4 to 0.8 mm. Obviously, the ITO layer 1104 must be substantially thin to be transparent. It is also possible to deposit the holographic layer on a thin plastic substrate. A flexible plastic substrate can also be used.

A first voltage is applied to the ITO layer 1104 to switch the holographic layer 1
An electric field is generated at 106, causing the switchable holographic element to become inactive as described above. However, if the voltage on the ITO layer 1104 is lower than the first voltage, the switchable holographic optical element will be in the active state described above. In the active state, the electrically switchable holographic optical element diffracts, for example, the red bandwidth component of the collimated incident light 112,
On the other hand, the remaining portion of the collimated incident light 112, including the green and blue bandwidth components, passes substantially undeflected.

The switchable holographic optical element shown in FIG. 11 is either reflective or transmissive. FIG. 11 shows a switchable holographic optical element with opposing front and rear surfaces 1110 and 1112. Regardless of the reflection type or the transmission type, the collimated white light 106 is incident on the front surface 1110 at a normal incident angle. If the switchable holographic optical element is formed as transmissive, the diffracted light component exits from the rear surface 1112. In contrast, if the electrically switchable holographic optical element is formed as a reflection hologram, the diffracted light component exits the front surface 1110. Transmissive electrically switchable holographic optical elements can be used in the switchable optics shown in FIGS. 1, 2 and 3, and reflective electrically switchable holographic optical elements can 4 and the switching type optical system shown in FIGS.

The switchable holographic layer 1106 can record holograms by conventional techniques. In one embodiment, the resulting hologram has a high diffraction efficiency,
The feature is that the speed at which the optical element switches from the active state to the inactive state is high. In one embodiment of a switchable holographic layer 1106 formed from a polymer dispersed liquid crystal (PDLC) material, the recorded hologram is generated or extinguished by the above-described electric field to change from a diffractive state to a transmissive state. Can be switched. The hologram recorded in the switchable holographic layer 1106 can be combined with a Bragg (known as a thick layer or volume layer) to obtain high diffraction efficiency.
It is desirable to make a mold. The hologram recorded in the switchable holographic layer 1106 may be based on the PDLC material described in application Ser. No. 09 / 478,150. Utilization of this is part of the present specification. In one embodiment, the hologram is the recording light, ie the switchable holographic layer 1.
Interference fringes generated by the comparative light beam and the object wave interacting in 106. Photopolymerization occurs due to light interacting with the PDLC material. The liquid crystal particles enter into the dark area of the stripe pattern formed by the intersection of the recording light during recording. In other words, the recording material is a polymer-dispersed liquid crystal mixture that separates during recording and produces areas of high density of liquid crystal particles interspersed by areas of transparent photopolymer. When a sufficiently high voltage is applied to the ITO layer 1104, the direction of the liquid crystal particles is changed, the refractive index of the switchable holographic layer 1106 is changed, and the hologram recorded therein is substantially erased. All of the collimated white light 106 is transmitted without being noticeably deflected. The material used for the switchable holographic layer 1106 is such that it operates at a very fast switching speed (eg, much faster than conventional liquid crystal materials, the material switches in tens of μs) and has high diffraction efficiency. Manufactured.

FIG. 12 shows an ES that can be used in the switching optical system used in FIGS. 2 and 3.
It is a block diagram of one Example of a HOE system. Specifically, the ESHO shown in FIG.
The E-system includes three groups of three electrically switchable holographic optical elements. The first group 1202 consists of three holographic optical elements 1202A-1202C stacked on one another. A second group of holographic optical elements 1204 comprises three holographic optical elements 1 stacked on top of each other.
204A to 1204C. Third group of holographic elements 1208
Are three holographic optical elements 1208A-1208C stacked on top of each other.
Consists of

In operation, the ESHOE system shown in FIG. 12 is used to direct red, green, and blue illumination light to the partial surfaces 114A-114C, as shown in FIGS. 7A-7C. During each phase of the three-phase cycle described with reference to FIGS. 7A-7C, each of the electrically switchable holographic optical elements in one of the three groups 1202-1208 is activated. More specifically, in the first stage described above, the electrically switchable holographic optical elements 1202A-1202C of group 1202 are activated. In the second stage of the illumination cycle described above, the electrically switchable holographic optical elements 1204A-120C of group 1204 are activated. In the third phase of the three-phase cycle described above, each of the electrically switchable holographic optical elements 1208A-1208C of the third group 1208 is activated. The lighting control circuit 118 applies a suitable active or inactive voltage so that only one group is active at any given time,
The groups 1202-1208 are sequentially and periodically made active and inactive.

Referring to FIG. 2, an electrically switchable holographic optical element 1202 A
And 1204A and 1208A, when active, diffract the output light 204R to each of the partial surfaces 114A and 114B and 114C. Electrically switchable holographic optical elements 1202B and 1204B, 1208B, when active, output light 24 on each of partial surfaces 114B and 114C, 114A, respectively.
Diffracts 0G. Active holographic optical elements 1202C and 1
204C and 1208C are partial surfaces 114C and 114B, 114A, respectively.
Diffracts the output light 204B.

Referring still to FIG. 12, and further to FIG. 3, electrically switchable holographic optical elements 1202A and 1204A, 1204A provide white light 106 collimated on partial surfaces 114A and 114B, 114C, respectively. , While diffracting the remaining components of the incident collimated white light 106 substantially undeflected. The portion of the collimated white light 106 that passes through the electrically switchable holographic optical element in the active state enters free space and does not enter the display surface 114. This is because the diffracted light
This is because the display surface is arranged by utilizing the emission from the holographic optical element which can be electrically switched at a certain angle with respect to light passing therethrough without being substantially deflected. Electrically switchable holographic optical elements 1202B and 120
4B, 1208B diffract the green bandwidth component of the collimated white light 106 incident thereon, the diffracted light being incident on each of the partial surfaces 114B and 114C, 114A. Active optical elements 1202B and 1204B, 1
The remainder of the collimated white light 106 incident on 208B passes therethrough to free space without substantial deflection. Similarly, the active optics 1202C and 1204C, 1208C diffract the blue bandwidth component of the collimated white light 106 incident thereon, and the diffracted blue bandwidth component is reduced to the partial surfaces 114C and 114B, 114A.

FIG. 13 shows an ESHOE system used in the embodiment of FIGS. 1 and 4. The ESHOE system of FIG. 13 includes three groups of three electrically switchable holographic optical elements. The first group 1302 includes three electrically switchable holographic optical elements 1302A and 1302B, 1302C, each diffracting red bandwidth light when active, while green and blue bandwidths. Is formed so as to be transmitted without being deflected. In the inactive state,
Each of the switchable holographic optical elements 1302A and 1302B, 1302C transmits the red, green, and blue bandwidths without deflection. Diffracted red bandwidth light can be switched at different exit angles with holographic optical element 1302
A and 1302B, exit at 1302C at respective angles, and a partial surface 114A
Illuminate each -114C.

A second group 1304 includes three electrically switchable holographic optical elements 1304A and 1304B, 1304C that, when active, turn green bandwidth light while red and blue bands. Light having a width is generated so as to be transmitted without being deflected. When inactive, the electrically switchable holographic optical elements 1304A and 1304B, 1304C transmit light in the red, green, and blue bandwidths without deflection. Diffracted green bandwidth light can be electrically switched at different exit angles with holographic optical elements 1304A and 1304B,
1304C, each illuminating the respective partial surface 114A-114C.

A third group 1306 includes three electrically switchable holographic optical elements 1306A and 1306B, 1306C, each of which when active, diffracts light in the blue bandwidth while red and It is formed so as to transmit green bandwidth light without deflection. When inactive, each of the electrically switchable holographic optical elements 1306A and 1306B, 1306C transmits light in the red, green, and blue bandwidths without deflection. Diffracted blue bandwidth light is transmitted to electrically switchable holographic optical elements 1306A and 1306B.
, 1306C, exiting at different angles from each of the partial surfaces 114A
Illuminate -114C.

The ESHOE system shown in FIG. 13, which operates under the control of the control circuit 118,
A-Operates to illuminate display surface 114 as shown in FIG. 7C. In this mode, the control circuit activates only one electrically switchable holographic optical element in each of the groups 1302-1306.
More specifically, the control circuit in the first cycle activates the electrically switchable holographic optical elements 1302A and 1304B, 1306C, illuminating the display surface 114 as shown in FIG. 7A. In a second cycle, the control circuit provides an electrically switchable holographic optical element 1302C.
And 1304A and 1306B are activated, illuminating the display surface 114 as shown in FIG. 7B. In the third cycle, the control circuit determines that the electrically switchable holographic optical elements 1302B and 1304C, 1306
A is activated, illuminating the display surface 114 as shown in FIG. 7C.

FIG. 14 shows the ESHOE-based electrically switchable holographic optical element of FIG. 12 shifted. The ESHOE of FIG. 14 can be used to orient the collimated white light 106.

Using the set of ESHOE systems shown in FIGS. 12 and 13 as the switchable optical system, the intensity of illumination light for illuminating the monochromatic component on the display surface can be increased. More specifically, the two ESHOE systems of FIG. 13 or FIG. 14 are made two, and the two ESHOE systems are arranged side by side on both sides of the central deflection rotator. In this arrangement, the collimated light 1
Each of the 06 s and p polarization components or output light 204R-204B is diffracted by one of two ESHOE systems with a rotator in between. Alternatively, FIG.
3 or two of the ESHOE systems of FIG. 14 with the diffraction grating in each of the electrically switchable holographic optical elements of one of the ESHOE systems
The diffraction grating of each electrically switchable holographic optical element of the OE system is arranged orthogonally. For these arrangements, see US patent application Ser.
No. 78,150, which is hereby incorporated by reference.

The ESHOE system can be used to illuminate a display surface divided into three partial surfaces with R, G, and B illumination light. Another ESHOE system can be used, for example, to illuminate a display surface divided into three partial surfaces shown in FIGS. 9A-9F. FIGS. 15 and 16 show an ESHOE system that can be used to generate the illumination patterns shown in FIGS. 9A-9F. The ESHOE system shown in FIG. 15 can be used for the systems shown in FIGS. 1, 3, 4 and 6. Generally, the electrically switchable holographic optical elements required for each of the ESHOE systems (formed to diffract only one of the s or p polarization components of collimated light 106 or output light 204R-204B). The total number is the number of different illumination lights (
Usually, it is equal to 3) multiplied by the number of partial surfaces of the display surface 114 for displaying the single color component of the final image.

FIG. 17 shows an embodiment of the system shown in FIG. Collimating lens 10
The collimated white light 106 emitted from 4 enters the 202B. The filtered output lights 204R-204B enter the ESHOE system 1200. As shown in FIG. 12, the ESHOE system 1200 consists of three electrically switchable holographic optical elements stacked on top of each other. Each of these elements directs and collects the output light of each wavelength bandwidth emitted from the filter 202B to one of the partial surfaces 114A-114C. The state shown in FIG. 17 activates the electrically switchable holographic optical elements 1202A-1202C (see FIG. 12) and the electrically switchable holographic optical element 1
This is accomplished by the illumination control circuit 118 rendering the 204A-1204C and 1206A-1206C inactive.

FIG. 18 is another embodiment of the optical system shown in FIG. In this embodiment, light emitted from the light source 100 is collimated and enters the filter 202A. The output light 204R-204B is applied to a transparent plate 180 for generating illumination light.
2 is incident on the ESHOE system 1200 mounted on the front surface of it and is redirected there. After being redirected, the illumination light is completely reflected inward by the rear surface of the plate 1802 and is incident on a device 1804 (mounted on the front surface of the plate 1802) which corrects the collection and backscattered monochromatic illumination light. . Next, the illumination light is applied to the partial surface 1
14A-114C. Referring to FIG. 12, the ESHOE system 1200 of FIG.
Includes a stack of three electrically switchable holographic optical elements. An illumination control circuit (not shown in FIG. 18) activates only the electrically switchable holographic optical element in one of the stacks to illuminate the partial surface.

The electrically switchable holographic optical elements of the ESHOE system 1200 operate off-axis and exceed the measurement range of spectral bandwidth, requiring correction of monochromatic and geometric optical aberrations, and the device 104. Has been corrected. In one example, apparatus 1100 comprises stacked holographic diffraction elements designed to operate on red, green, and blue bandwidth light, respectively. Because the angles separating the R, G, and B illumination light are relatively large (greater than the angle of the Bragg hologram bandwidth in these elements), the measurable light crosstalk between the red, green, and blue wavelengths (cross- It is easy to select a Bragg angle and a wavelength at which no talk occurs. In such a case, these elements of device 1804 need not be switchable.

As mentioned above, the electrically switchable holographic optical element operates effectively only on the p-polarized component of the incident light, while the s-polarized component is substantially unaffected. That is, it is not diffracted by the electrically switchable holographic optical element. As a result, half of the available light is lost. To prevent this, one ESHOE system 1200 of FIG. 18 is replaced by a set of ESHOE systems 1200 and a polarization rotator is placed therein. In this embodiment, the p-polarized component of the light incident on the first switchable holographic optical element of the first ESHOE system is diffracted, and the s-polarized component is transmitted substantially unaffected. . A polarization rotator (eg, a colorless half-wave plate) is designed to change the direction of polarization of transmitted light by 90 degrees. Therefore, the p-polarized light diffracted by the first ESHOE system is s-polarized, and the s-polarized light that is not diffracted is p-polarized. In the second ESHOE system, the p-polarized component is diffracted, and the s-polarized component is transmitted substantially unaffected. The properties of the electrically switchable holographic optical elements in the two ESHOE systems are such that in each case the angle of emergence of the diffracted light is the same, and both the p- and s-polarized components are in the same direction. Are selected to be emitted.

Alternatively, instead of a polarization rotator, the fringes of the hologram recorded on the electrically switchable holographic optical elements of the two ESHOE systems are replaced by a first E
The electrically switchable holographic optical elements in the SHOE system operate on the p-polarized component and the elements in the second ESHOE system are arranged crosswise to operate on the s-polarized component. The properties of the hologram in each ESHOE system are chosen such that the diffracted p-polarized component and s-polarized component exit in the same direction.

FIG. 19 is another embodiment of the system shown in FIG. Here, FIG. 10C
The collimated white light emitted from the collimator lens 104 is filtered by using the filter 202C of (1). Further, this switching type optical system is an ESHOE1
200, and an optical corrector 1902 disposed between the filter 202C and the ESHOE 1200. The purpose is to correct optical aberration, and will be described later.

FIG. 20 is a side view and a front view of one embodiment of the optical system in which the ESHOE 1200 shown in FIG. 5 is a reflection type. The optical system shown in FIG.
It is similar to the optics shown in FIG. 19 in that it uses a filter 202C to filter the collimated light from 04. The front view shows how the output lights 204R, G, and B are diffracted by the ESHOE 1200 to generate illumination lights R, G, and B that sequentially illuminate the display surface 114.

Further, the front view shows illumination light (ie, diffracted output light) emitted from the ESHOE system at a measurement angle with respect to the angle at which the output light is incident on the incident surface of the ESHOE system 1200. In order for an electrically switchable holographic optical element to achieve high efficiency diffraction, a suitable diffraction angle is required. Further, it should be noted that reflective electrically switchable holographic optical elements are insensitive to the polarization state of light incident at moderate angles of incidence and diffraction. Therefore, no means for avoiding polarization loss is required.

FIG. 21 shows that instead of being oriented in the image plane, the illumination light R and G, B are incident on the intermediate optical diffuser 2102. Diffusers are used to control the properties of light so that the illumination light has the same polar diagram. The diffuser is preferably a holographic light shaping diffuser formed by stacking non-switchable holographic optical elements according to the prior art.

FIG. 22 shows another embodiment of the optical system shown in FIG. The ESHOE system 1200 shown in FIG. 12 is used for the switchable optical system shown in FIG. However, groups of electrically switchable holographic optical elements are not arranged side by side. Instead, electrically switchable holographic optical elements 1202 and 120
The groups 4 and 1206 are respectively arranged adjacent to the incident surface of the dichroic prism. Collimated light 106 is filtered by filter 202B into output light 204R-204B. The output light 204R is transmitted to the plane mirror 22.
After being deflected by 90 degrees by 04 and diffracted by one of the active, electrically switchable holographic optical elements of group 1202, it impinges on the entrance surface of a dichroic prism. Similarly, the output light 204B is deflected by 90 degrees by the plane mirror 2206, diffracted, and then incident on another incident surface of the dichroic prism. Output light 204G is incident on the third entrance surface of the dichroic prism after being diffracted by one of the active, electrically switchable holographic optical elements of group 1204. The dichroic prism converts the diffracted light (i.e., the illumination light R, G, B) before illuminating the image surface 114 with a color correction element disposed after the exit surface of the dichroic prism. Reorient to 2202. FIG. 23 is a modification of the optical system shown in FIG. 22, in which the plane mirrors 2204 and 2206 are replaced by total internal reflection prisms 2304 and 2306. FIG. 24 shows a further embodiment of FIG. 22, wherein the filters 202B and 204B are such that output light 204R-204B is respectively incident on a group of electrically switchable holographic optical elements 1202-1206 at angles greater than 90 degrees. Filter element and flat mirror 2206
Is arranged. Note that planar mirror 2204 is not used in this alternative. In both cases, the output light is emitted to the exit surface of the holographic optical element where the diffracted light is usually electrically switchable.

In the arrangement shown in FIG. 18, the illuminating light incident on any point on the display surface overlaps exactly and appears to be generated from a common point. This is an important factor in many reflective display devices. In such a reflective display device, the brightness of the final image projected is not due to scattering (as opposed to a transmissive LCD) but to specular reflection of the display device. In the embodiment described above, the output light does not match in this way and can be modified using a diffusion screen (as shown in FIG. 21) before being used in a reflective non-diffusing display. .

FIG. 25 shows another embodiment of the present invention. The image plane 114 shown in FIG. 25 consists of an array of pixels 2502. The pixels are divided into three sets, with each pixel in each set being evenly distributed across the image plane 114. FIG. 25 is a cross-sectional view of a single pixel of the arrayed image plane. The image control circuit controls the display of the monochrome image on the image plane 114 so that each pixel in each set always displays one of the red, green, and blue components of the final image (monochrome), and Are controlled such that each pixel in the sequence sequentially displays the final image component.

FIG. 25 also shows the ESHOE system 2504. This ESHOE system uses illumination light R
Or having a plurality of groups of three electrically switchable holographic optical elements 2504A-2504C used to illuminate the pixels in G, B.
Although not shown, three electrically switchable holographic optical elements 25
The number of groups consisting of 04A-2504C is equal to the number of pixels in a single pixel. FIG. 25 shows one group of three electrically switchable holographic optical elements 2504A-2504C. Collimating lens (
(Not shown) must be incident on the ESHOE system 2504. The ESHOE system 2504 filters, orients, and condenses the white light 106 collimated by diffraction, and illuminates each pixel with R or G, B illumination light. The red illumination light R is directed to those pixels 2502 which are then displaying the red monochromatic component of the final image. The green illumination light G is directed to those pixels 2502 which are then displaying the green monochrome component of the final image. The blue illumination light B is directed to those pixels 2502 which are then displaying the blue monochromatic component of the final image.

The ESHOE system 2504 is controlled by the circuit 118 such that only one of the electrically switchable holographic optical elements 2504A-2504C in each group is active at any given time. Further, only those pixels 2502 representing the red, green, and blue monochromatic components of the final image are R or G, B
The control circuit is synchronized with the image control circuit 116 so as to be illuminated with the illumination light.

Electrically switchable holographic optical element 2 in each group
Each of 504A-2504C includes one in which three holographic lenses (preferably microlenses) formed on the hologram recording medium are overlapped.
Each lens, when activated by a suitable signal generated by the illumination control circuit 118, acts on each of the red, green, and blue bandwidth components of the collimated light 106. In FIG. 25, each of the holographic lenses that diffract light in the red bandwidth is indicated by diagonal lines, each holographic lens that diffracts light in the green bandwidth is blank, and each holographic lens that diffracts light in the blue bandwidth is blank. Holographic lenses are indicated by a number of points. The three stacked lenses in each of the electrically switchable holographic optical elements comprise a set of electrode layers (ITO).
, And all the lenses are activated by a control signal supplied to the pair of electrodes by the control circuit 118. Alternatively, it is also possible to switch each or each of the stacked lenses in the electrically switchable holographic optical element to an appropriately active or inactive state. However, such an embodiment requires a separate set of ITO layers for each lens or lens in each row.

FIGS. 26A to 26C show the operation of the ESHOE system 2504 shown in FIG. FIGS. 26A-26C show only pixels 2502A-2502C and one of the multiple lenses of each electrically switchable holographic optical element in groups 2504A-2504C.
FIG. 26A shows the first stage of a three stage cycle, where pixel 2502A-2
502C displays the green, red, and blue monochromatic components of the final image, respectively. At this stage, the holographic lens at 2504A in the first group is
Since all are in the active state by 18, 25 in the first group
The red lens included in 04A is the collimated white light 106 incident thereon.
The red bandwidth component of is directed to pixel 2502A and collected, and other bandwidth light incident thereon passes without noticeable deflection. The green lens included in the first group 2504A is the collimated white light 1 incident thereon.
The green bandwidth component of 06 is directed and collected at pixel 2502B, and other bandwidth light incident thereon is transmitted without noticeable deflection. The blue lens included in the first group 2504A also directs and concentrates the blue bandwidth component of the collimated white light 106 incident thereon to the pixel 2502C, and the other incident thereon. Bandwidth light is transmitted without noticeable deflection. The lens indicated by the broken line is in an inactive state by the control circuit 118. These lenses transmit light substantially undeflected.

In the second phase of the three-phase cycle shown in FIG.
2A-2502C respectively display the red, blue and green monochromatic components of the final image.
At this stage, the holographic lenses included in the second group 2504B are all activated by the control circuit 118.
The red lens included in the group 2504B collects the red bandwidth component of the collimated white light 106 incident thereon by directing it to the pixel 2502A and condensing the other bandwidth light incident thereon. Transmission without noticeable deflection. The green lens included in the first group 2504B also directs and condenses the green bandwidth component of the collimated white light 106 incident thereon to the pixel 2502C, and the other bandwidth incident thereon. Is transmitted without being noticeably deflected. The blue lens included in the first group 2504B also directs and collects the blue bandwidth component of the collimated white light 106 incident thereon to the pixel 2502B,
Light of other bandwidths incident thereon is transmitted without being noticeably deflected.

In the last stage of the three stage cycle shown in FIG. 26C, pixel 2502A
-2502C displays the blue, green, and red single color components of the final image, respectively. Also, at this stage, the holographic lenses included in the second group 2504C are all activated by the control circuit 118, so that the red lenses included in the first group 2504C are The red bandwidth component of the white light 106 is focused and focused on the pixel 2502C, and the light of the other bandwidth incident thereon is transmitted without being noticeably deflected. The green lens included in the first group 2504C also directs and condenses the green bandwidth component of the collimated white light 106 incident thereon to the pixel 2502B, and the other bands incident thereon. Light of a width is transmitted without being noticeably deflected. The blue lens included in the first group 2504C also directs and concentrates the blue bandwidth component of the collimated white light 106 incident thereon to the pixel 2502A, and the other bands incident thereon. Light of a width is transmitted without being noticeably deflected.

The three-step cycle is repeated for the next final image. At this time, the switching between the steps must be performed promptly. In this way, the observer will always use all of the red, green, and blue components of the collimated white light 114,
4 appears to be displayed as a full-color image. If a particular pixel displays some final image that lacks one or more monochromatic components at any one time, during that particular operation the illumination light will not be directed to that pixel and will not be collected. During this cycle, the pixel does not display a particular color. For example, if a given pixel displays a portion of an image having only red spectral components, no green or blue illumination light will be focused there.

In a further embodiment of the image forming apparatus shown in FIG. 27, the image plane 114 is arranged with pixels as shown in FIG. However, in this embodiment, the collimated light 106 is reflected from the ESHOE system 2700 toward the orienting device 2704, where red, green, and blue illumination light is directed to the pixel 2502.

More specifically, the ESHOE system 2700 consists of three reflective, electrically switchable holographic optical elements. In one embodiment, the electrically switchable holographic optical elements 2702A-2702C can be arranged in a manner similar to that shown in FIG. No separate group of optical elements is required. Alternatively, each of the electrically switchable holographic optical elements could be embedded in three large holographic mirrors. Reflective, electrically switchable holographic optical elements operate similarly to mirrors in that light exits from the same plane as the plane of incidence. However, in reflective electrically switchable holographic optical elements, the incident light is diffracted and the diffracted light exits from the same surface as the incident surface.

The electrically switchable holographic optical elements are indicated by arrows A and B, C, respectively.
Are arranged to diffract the red, green, and blue components of light 106 at three predetermined exit angles. The control circuit 118 sequentially activates each of the electrically switchable holographic optical elements 2702A-2702C. Thus, when one element is active, the other two elements are not active. When element 2702A is active, red illumination light is emitted in the direction of arrow A, and green and red illumination light are respectively represented by arrows B and C.
In the direction of When the element 2702C is active, the red light is
, And green and blue light are emitted in the directions of arrows A and B, respectively.

The orienting device 2704 is substantially composed of a passive optical element (an element such as a lens or an array of prism-like elements such as a holographic element) that deflects an angle of incident light according to its wavelength. Apparatus 2704 directs light incident from the direction of arrow A onto one set of pixels 2502 and directs light incident from the directions of arrows B and C onto second and third sets of pixels. . Each set of these pixels is such that each set displays any of the red, green, and blue monochromatic components of the final image at any given time, and each set sequentially displays all of these image components. Is controlled by the control circuit 116. Control circuit 11
6 and 118 operate synchronously. For example, when the electrically switchable holographic optical element 2702A is active, the device 2704 directs red light onto the pixels that are now displaying the red monochromatic component of the final image. Other aspects of the operation of the device of this embodiment are similar to those described with reference to FIG.

In the preferred embodiment of the device described above, the orientation device 2704 is formed from a combination of three holographic elements, each optimized to operate at the red, green, and blue wavelengths.

Although the present invention has been described with reference to what is presently considered to be the most practical and preferred embodiment, the present invention is not limited to the disclosed embodiment, but includes various improvements and modifications. Is considered to be within the scope of the present invention.

[Brief description of the drawings]

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example and will be described in detail below with reference to the drawings. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular embodiments disclosed. The present invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. The invention may be better understood with reference to the accompanying drawings,
Its various objects, features and advantages will be apparent to those skilled in the art.

FIG. 1 is a diagram illustrating a first embodiment of a transmission type element for generating colored light and an image generation apparatus.

FIG. 2 is a diagram illustrating a second embodiment of a transmission-type element for generating colored light and an image generating apparatus.

FIG. 3 is a diagram illustrating a third embodiment of a transmissive element for generating colored light and an image generating apparatus.

FIG. 4 is a diagram showing a first embodiment of a reflection-type element for generating colored light and an image generating apparatus.

FIG. 5 is a diagram showing a second embodiment of a reflection-type element for generating colored light and an image generating apparatus.

FIG. 6 is a diagram showing a third embodiment of a reflection-type element for generating colored light and an image generating apparatus.

FIG. 7A illustrates an operational aspect of one embodiment of a switchable optical system and image surface that can be used in the embodiments shown in FIGS.

FIG. 7B illustrates an operational aspect of one embodiment of a switchable optical system and image surface that can be used in the embodiments shown in FIGS.

FIG. 7C illustrates an operational aspect of one embodiment of a switchable optical system and an image surface that can be used in the embodiments shown in FIGS.

FIG. 8 illustrates an operational aspect of another embodiment of a switchable optical system and image surface that can be used in the embodiments shown in FIGS. 1-6.

FIG. 9A illustrates an operational aspect of yet another embodiment of a switchable optical system and image surface that can be used in the embodiments shown in FIGS.

9A and 9B illustrate operational aspects of yet another embodiment of a switchable optical system and image surface that can be used in the embodiments shown in FIGS.

FIG. 9C illustrates the operational aspects of yet another embodiment of a switchable optical system and image surface that can be used in the embodiments shown in FIGS.

FIG. 9D illustrates the operational aspects of yet another embodiment of a switchable optical system and image surface that can be used in the embodiments shown in FIGS.

FIG. 9E illustrates an operational aspect of yet another embodiment of a switchable optical system and image surface that can be used in the embodiments shown in FIGS. 1-6.

FIG. 9F illustrates an operational aspect of yet another embodiment of a switchable optical system and image surface that can be used in the embodiments shown in FIGS. 1-6.

FIG. 10A illustrates another embodiment of a filter that can be used in the embodiments shown in FIGS. 2 and 5.

FIG. 10B shows another embodiment of a filter that can be used in the embodiments shown in FIGS. 2 and 5.

FIG. 10C illustrates another embodiment of a filter that can be used in the embodiments shown in FIGS. 2 and 5.

FIG. 11 is a cross-sectional view of an electrically switchable holographic optical element.

FIG. 12 illustrates one embodiment of an electrically switchable holographic optical element that can be used in the switchable optics of FIGS. 2, 3, 5, and 6;

FIG. 13 illustrates one embodiment of an electrically switchable holographic optical element that can be used in the switchable optics of FIGS. 1 and 4.

FIG. 14 illustrates one embodiment of an electrically switchable holographic optical element that can be used in the switchable optics of FIGS. 3 and 6;

FIG. 15 illustrates another embodiment of an electrically switchable holographic optical element that can be used in the switchable optics of FIGS. 2, 3, 5 and 6;

FIG. 16 illustrates another embodiment of an electrically switchable holographic optical element that can be used in the switchable optics of FIGS. 1 and 4.

FIG. 17 is a diagram showing one embodiment of the optical system shown in FIG. 2;

FIG. 18 is a diagram showing another embodiment of the optical system shown in FIG. 2;

FIG. 19 is a view showing still another embodiment of the optical system shown in FIG. 2;

FIG. 20 is a diagram showing one embodiment of the optical system shown in FIG.

FIG. 21 illustrates an electrically switchable holographic optical element and light diffuser that can be used in the embodiments shown in FIGS.

FIG. 22 illustrates another embodiment of a switchable optical system that can be used in the embodiment of FIG.

FIG. 23 is a diagram showing a switchable optical system according to a modification of FIG. 22;

FIG. 24 is a diagram showing a switchable optical system according to a modification of FIG. 22;

FIG. 25 is a diagram showing a fourth embodiment of a transmissive element for generating colored light and an image generating apparatus.

26A is a diagram showing an operational aspect of a transmission type element for generating colored light shown in FIG. 25. FIG.

FIG. 26B is a diagram showing an operational aspect of the transmission type element for generating colored light shown in FIG. 25;

26C is a diagram showing an operational aspect of the transmission type element for generating the colored light shown in FIG. 25. FIG.

FIG. 27 is a diagram showing a fourth embodiment of a reflection-type element for generating colored light and an image generating apparatus.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02F 1/29 G02F 1/29 H04N 9/31 H04N 9/31 C (31) Priority claim number 60/157 , 796 (32) Priority date October 5, 1999 (1999.10.5) (33) Priority country United States (US) (81) Designated country EP (AT, BE, CH, CY, DE, DK) , ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR) , NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ , TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CR, CU, CZ, DE, DK, DM, EE, ES, FI , GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, TZ, UA , UG, US, UZ, VN, YU, ZA, ZWF term (reference) 2H049 AA25 AA43 AA50 AA60 AA68 2H088 EA15 EA48 FA30 HA12 HA24 HA28 MA20 2H091 FA14Z FA26X FA41Z GA01 JA02 LA30 2K002 AA07 AB06 AB07 AB07 AB07 BA08 BB13 BC01 HB07 HC00 JA25 JB06

Claims (23)

[Claims] 1. An apparatus, comprising: first, second and third electrically switchable holographic optical elements, each of said holographic optical elements being electrically connected between an active state and an inactive state. A switchable optical system comprising a first group of electrically switchable holographic optical elements that are switchable, wherein said first, said second and said third electrically switchable holographic optical elements. Are each configured to diffract incident light when operating in the active state, and wherein the first, second and third electrically switchable holographic optical elements are each configured to be in the inactive state. The switchable optical system, which transmits the incident light substantially unchanged when operating in the first, the first, the second and the third electrically switchable holography A first control circuit connected to the optical element, wherein the first, second, and third electrically switchable holographic optical elements are controlled by the control circuit to the active state and the inactive state. And the control circuit, wherein the light diffracted by the first electrically switchable holographic optical element passes through a first area of a plane, and the second electrically switchable Light diffracted by the possible holographic optical element passes through a second area of the plane, and light diffracted by the third electrically switchable holographic optical element is transmitted by a third area of the plane. And wherein the second region is located between the first region and the third region of the plane. 2. The apparatus of claim 1, wherein the first, second and third electrically switchable holographic optical elements are each configured to diffract incident light of a first bandwidth. The device according to claim 1. 3. The first, second and third electrically switchable holographic optical elements are each individually switchable between the active state and the inactive state by the first control circuit. 3. The device according to claim 2, wherein the device is configured as follows. 4. The control circuit as claimed in claim 1, wherein only one of the first, second and third electrically switchable holographic optical elements is active at any time. 4. The method of claim 3, wherein the first, second, and third electrically switchable holographic optical elements are sequentially and periodically switched between the active state and the inactive state. The described device. 5. The first, second, and third electrically switchable holographic optical elements are configured to diffract incident light of first, second, and third bandwidths, respectively. The apparatus of claim 1, wherein incident light of the first, second, and third bandwidths are different from each other. 6. The first, second, and third electrically switchable holographic optical elements are collectively switched between the active state and the inactive state by the control circuit. The apparatus according to claim 5, wherein 7. Each of said electrically switchable holographic optical elements comprises a holographic recording medium for recording a hologram, said holographic recording medium comprising a monomer dipentaerythritol hydroxypentaacrylate (dipent).
The device of claim 1, comprising: aerythritol hydroxypentaacrylate), a liquid crystal, a crosslinking monomer, a coinitiator, and a photoinitiator dye. 8. The electrically switchable holographic optical elements each include a hologram formed by exposing an interference pattern in a polymer dispersed liquid crystal material, wherein the polymer dispersed liquid crystal material is polymerized prior to exposure. The device of claim 1, comprising a possible monomer, a liquid crystal, a crosslinking monomer, a coinitiator, and a photoinitiator dye. 9. The second group of electricity, wherein the photo-orientation device further comprises first, second and third electrically switchable holographic optical elements connected to the first control circuit. Switchable holographic optical elements, wherein the first, second, and third electrically switchable holographic optical elements of the second group each have an active state and an inactive state. The first, the second and the third electrically switchable holographic optical elements of the second group are each electrically switchable between the active state and the non-active state by the control circuit. The first, the second and the third electrically switchable holographic optical elements of the second group each being switched between active states. The first, second, and third electrically switchable holographic optical elements of the second group are each configured to diffract incident light when operating in the active state, A second group of electrically switchable holographic optical elements that transmit incident light substantially unchanged when operating in an inactive state; and a first group connected to the first control circuit. A third group of electrically switchable holographic optical elements comprising said second and third electrically switchable holographic optical elements, wherein said first and said second groups of said third group are electrically switchable. 2 and the third electrically switchable holographic optical element are each electrically switchable between an active state and an inactive state, and Each of said first, second and third electrically switchable holographic optical elements is switched between said active state and said inactive state by said control circuit, and The first, second, and third electrically switchable holographic optical elements are each configured to diffract incident light when operating in the active state, and wherein the first, second, and third electrically switchable holographic optical elements diffract incident light when operating in the active state. A third group wherein each of the first, second and third electrically switchable holographic optical elements transmits incident light substantially unchanged when operating in the inactive state. Electrically switchable holographic optical elements of the second group of said first electrically switchable holographic optical elements. The light to be folded passes through the third area of the plane, and the light diffracted by the second group of electrically switchable holographic optical elements of the second group is the first area of the plane. The light diffracted by the third electrically switchable holographic optical element of the second group passes through the second area of the plane, and the first group of the third group The light diffracted by the electrically switchable holographic optical element of the first group passes through the second region of the plane and is diffracted by the second electrically switchable holographic optical element of the third group. Light passes through the third region of the plane, and light diffracted by the third electrically switchable holographic optical element of the third group is transmitted to the first region of the plane. Apparatus according to claim 1, characterized in that passing through the pass. 10. The first, second, and third electrically switchable holographic optical elements of the first group are each configured to diffract incident light of a first bandwidth. The first, second and third electrically switchable holographic optical elements of the second group are each configured to diffract incident light of a second bandwidth; Wherein the first, second and third electrically switchable holographic optical elements are each configured to diffract incident light of a third bandwidth, and wherein the first, second and The apparatus of claim 9, wherein the third bandwidth is different from the third bandwidth. 11. The first electrically switchable holographic optical elements are each configured to be individually switched between the active state and the inactive state by the first control circuit, and The second electrically switchable holographic optical elements are each configured to be individually switched between the active state and the inactive state by the first control circuit, and wherein the third electrically switchable holographic optical elements are configured to be individually switched between the active state and the inactive state by the first control circuit. The apparatus of claim 10, wherein each switchable holographic optical element is configured to be individually switched between the active state and the inactive state by the first control circuit. 12. The first control circuit controls the first electrical switch such that only one of the first electrically switchable holographic optical elements is active at any time. And the first control circuit is configured to sequentially and periodically switch the holographic optical elements that can be switched between the active state and the inactive state. The second electrically switchable holographic optical element is sequentially and periodically switched between the active state and the inactive state such that only one of them is active at any time. Also, the control circuit may be configured to cause only one of the third electrically switchable holographic optical elements to be active at any time. The third electrically switchable holographic optical element is configured to be sequentially and periodically switched between the active state and the inactive state, and the control circuit is configured to control the first, the second and the third at any time. 2 and the third
In each of the group of electrically switchable holographic optical elements:
The apparatus of claim 11, wherein only one of the electrically switchable holographic optical elements is configured to be active. 13. The first, second, and third electrically switchable holographic optical elements are configured to diffract incident light of first, second, and third bandwidths, respectively. 10. The apparatus of claim 9, wherein incident light of the first, second, and third bandwidths are different from each other. 14. The first control circuit according to claim 1, wherein the first, second, and third control circuits include:
Said first, said second of electrically switchable holographic optical elements of the group of
And the third electrically switchable holographic optical element is sequentially and periodically switched between the active state and the inactive state,
The first, second, and third electrically switchable holographic optics of only one of the first, second, and third groups of electrically switchable holographic optical elements. 14. The apparatus according to claim 13, wherein only the element is activated at any time. 15. A light source for generating light including light of first, second, and third bandwidths; a collimating lens for receiving and collimating light generated by the light source; A filter for receiving and filtering the light collimated by the collimating lens, wherein the filter filters the received and collimated light and spatially separate first, second, and third light. 3. The device according to claim 1, wherein the light is of a bandwidth of 3. 16. The first electrically switchable holographic optical element wherein the first electrically switchable holographic optical element is configured to receive and diffract light of the first bandwidth. An optical element is configured to receive and diffract the light of the second bandwidth, the third electrically switchable holographic optical element receives light of the third bandwidth, and The apparatus of claim 15, wherein the apparatus is configured to diffract. 17. A light source for generating light including light of the first, second, and third bandwidths, and a collimating lens for receiving and collimating light generated by the light source. Wherein the first, second, and third electrically switchable holographic optical elements are each configured to receive collimated light generated by the light source; Switchable holographic optical element, in an active state, transmits the second and third bandwidths of collimated light received by the first electrically switchable holographic optical element. And diffracts light of the first bandwidth of the collimated light received by the first electrically switchable holographic optical element. Wherein the second electrically switchable holographic optical element is in an active state, the first and the second of the collimated light being received by the second electrically switchable holographic optical element. Configured to transmit light of the third bandwidth and diffract light of the second bandwidth of the collimated light received by the second electrically switchable holographic optical element. Wherein the third electrically switchable holographic optical element is in an active state, the first and the second of the collimated light received by the third electrically switchable holographic optical element. The collimator transmits light of a second bandwidth and is received by the third electrically switchable holographic optical element. Apparatus according to claim 1, characterized in that it is configured to diffract light to said third bandwidth of light. 18. A display device, further comprising a display surface configured to display a monochrome image, wherein the display surface receives the first, second, and third diffracted light. The apparatus of claim 1, wherein the apparatus is configured. 19. The monochromatic image has first, second, and third monochromatic components, the first monochromatic component configured to receive the first diffracted light, and the second monochromatic component is configured to receive the first diffracted light. The monochromatic component of is configured to receive the second diffracted light, and the third monochromatic component is configured to receive the third diffracted light. 19. The device according to 18. 20. The display surface configured to simultaneously display the first, second, and third monochromatic components on first, second, and third partial surfaces, respectively, of the display surface. 20. The device of claim 19, wherein the device is configured to: 21. The display surface is configured to sequentially display the first, second and third monochromatic components on one partial surface of the display surface. Item 20. The device according to Item 19. 22. An apparatus, comprising: a switchable photo-alignment device configured to receive light; and a first control circuit connected to the switchable photo-alignment device. The apparatus is configured to receive a control signal from the first control circuit, and wherein the switchable photo-orientation device responsive to receiving the control signal, directs a first portion of the received light to a planar portion. Orienting a second portion of the received light to a second region of the plane, in response to receiving the control signal; A photo-alignment device that, in response to receiving the control signal, directs a third portion of the received light to a third region of the plane; wherein the second region is the first region And the third region. 23. An apparatus comprising a first surface and a second surface, wherein the first surface receives light and the second surface receives light received on the first surface. Apparatus configured to emit at least two portions, wherein the device directs the at least two portions of light and separates locations in an output plane.