Multiple image projection apparatus

Multi-image projection device

MULTIPLE IMAGE PROJECTION APPARATUS

The present invention generally relates to a projection device, and more specifically, relates to a projection device that can generate multiple images.

This application claims the priority of U.S. Provisional Patent Application No. 61/473,165 filed on April 8, 2011, and the disclosure of this application is incorporated herein by reference.

There are many applications that must display multiple images sequentially or simultaneously. Current devices capable of projecting multiple images are bulky, and are usually completely duplicates of single-image projection devices. Usually multiple light sources are required.

However, in this technology, there is a need for a small projection device capable of projecting multiple images, wherein the multiple images each display different image information as appropriate. This type of projector can be used for wide-screen projection, 3D image creation, and interactive imaging applications.

In one embodiment, the present invention is directed to a multi-image projection device having at least one first light source for providing light. There is further provided a cubic multi-faceted beam splitter, the beam splitter having four sides and two diagonal interfaces including one beam splitter element positioned on at least one diagonal interface; in some embodiments, one The mirror element is positioned on a part of one of the diagonal interfaces.

The first spatial light modulator and the second spatial light modulator such as the LCoS spatial light modulator are provided adjacent to the cube multiple mirror beam splitters.

The first LCoS spatial light modulator and the second LCoS spatial light modulator and the first light source are configured such that the first LCoS spatial light modulator and the first light source are positioned adjacent to the cube multi-beam beam splitter One side, and the second LCoS spatial light modulator and the second projection optical system share the cube multi-beam beam splitter, and one of the opposite sides faces the opposite side. In this configuration, the light from the first light source is formed into a first polarized beam and a second polarized beam guided in orthogonal directions by a polarized beam splitter, so that the first polarized beam is guided to In the first LCoS spatial light modulator, and guide the second polarized light beam to the second LCoS spatial light modulator.

A first image source modulates the first LCoS spatial light modulator, and a second image source modulates the second LCoS spatial light modulator for generating an image that can be the same or different from the image generated by the first image source Changer. The first LCoS spatial light modulator and the second LCoS spatial light modulator and the first projection optical system and the second projection optical system are configured so that the first modulated light from one of the first LCoS spatial light modulators The variable reflection output image is output to the first projection optical system, and a second modulated reflection output image from the second LCoS spatial light modulator is output to the second projection optical system.

In other embodiments, additional LCoS spatial light modulators and light sources are added as appropriate to generate 3-D images (when viewed with appropriate filters). The optional addition of the sensor allows the user to interact with the projected image, and the projected image is fed back to a controller to change the current or future image displayed by the system.

Refer to the drawings in detail, Figures 1A to 1C depict the image projection in the present invention The polarizing beam splitter cube structure used in the device. As seen in FIG. 1A, it includes four ridges 103, 104, 105, and 106. The four beams are joined together to form an integrated cubic integrated polarizing beam splitter 100. The surface coating 102 or other beam splitting elements are formed on the facets of each facet 103, 104, 105, and 106, facing the other facet; these elements are selected so that when the four facets are assembled These surfaces form a pair of orthogonal surfaces 108 and 109 of the scallop 100. In the embodiment of FIG. 1B, all the surfaces are selected to include polarizing beam splitter elements such as coatings, gratings, etc. so that two orthogonal diagonal beam splitter surfaces are created. In the embodiment of FIG. 1C, a mirror coating is coated with a mirror coating instead of a polarizing beam splitter element. The mirror coating reflects incident light with any polarization in a direction at 90° to the mirror surface. The mirror coating can be selected to form a thin film coating, such as aluminum, silver, gold or other metals or reflective coatings. Optionally, grating microstructures or MOF films (rather than polarizing beam splitter (PBS) coating materials) can also be attached between the two orthogonal surfaces 108 and 109 to serve as a polarizing beam splitter element.

2A and 2B depict a projection device 200 using the PBS cube 100 (with a mirror coating 107) of FIG. 1C. A single (non-polarized) light source 210 is incident on the PBS cube 100. The light source can be a white light source or a combined or ordered colored light source (for example, red, blue, and green LED light sources). On the same side of the cube as the light source 200 is the first reflective spatial light modulator 300. In an exemplary embodiment, the reflective spatial light modulator 300 is a liquid crystal on silicon (LCoS) modulator; however, any low-profile structure that can be positioned adjacent to the PBS cube 100 can be used in the projection device of the present invention Low profile reflection Sexual space light modulator. Exemplary spatial light modulators (for all embodiments of the present invention) include (but are not limited to) liquid crystal-on-silicon spatial light modulators, digital micromirror device spatial light modulators, digital light processor spatial light modulators A light modulator, a MEMS spatial light modulator, a liquid crystal spatial light modulator, a mirror-based spatial light modulator, or any other low-profile spatial light modulator that can process image information for projection. Note that depending on the projector application, the spatial light modulator in any projector can be the same type of spatial light modulator or two or more types of spatial light modulators.

On the opposite PBS cube surface on the same line as the incident light source 210 is the second reflective spatial light modulator 302; again, in this embodiment, the LCoS spatial light modulator is depicted as the light modulator 302, but Other reflective spatial light modulators can be selected. The incident light from the light source 210 passes through the incident light source optics 310 and enters the cube 100. When the light reaches the diagonal interface 109 of the coated polarization beam splitter, the light with one polarization passes through the cube in a straight line and is incident on the second reflective spatial light modulator 302. The light with the opposite polarization is reflected by the polarization beam splitter surface 109 and is reflected again by the polarization beam splitter surface 108 into the first modulator 300. In the embodiment of FIG. 2A, a straight line indicates P-polarized light, and a dashed line indicates S-polarized light. However, depending on the selected beam splitter element, the opposite configuration (reversing the P and S polarization) can also be used.

The modulated light with opposite polarization is reflected by each reflective spatial light modulator 300, 302. The light leaving the reflective spatial light modulator 300 is incident on the mirror surface 107 and reflected toward the first group of projection optics 402. Similarly, the light leaving the reflective spatial light modulator 302 is also directed by the mirror surface 107 The second set of projection optics 404 reflect. In this way, two modulated images are formed.

Depending on the application, the modulated images can be the same or different. For the application of FIG. 2A, it may be necessary to display the same image in two different positions and (as the case may be) in two different sizes. For example, the main image display can be selected to have a resolution of SVGA/XGA/720P/WSVGA with an active area of 0.3 to 0.4 inches; the smaller image projected from the projection optics 404 can be a WVGA resolution with an active area of about 0.2 inches Spend. In contrast, in the embodiment of Figure 2B, it may be necessary to display two different images on a single screen with the same image size and resolution, and these images are "stitched together" to form a single widescreen image (please See Figure 2C). Note that the projection screen can be a flat screen, a wall, a metal screen, or any surface that can be used for projection.

Figure 3 depicts a variation of the embodiment in Figure 2A including an image sensor. The projection device 400 includes two LCoS modulators 300 and 302 and two projection optical systems 402 and 404. In the image projected by the optical system 404, the interaction between the user and the image is captured by reflecting back through the optical system 404, reflected by the reflector 107, and guided to the image sensor by the diagonal surface elements of the polarizing beam splitterDevice410middle. The image sensor 410 is selected from any conventional optical image sensor such as CMOS or CCD sensor. In this way, the sensor captures the users input; through appropriate hardware and software, user input commands such as motion and/or handwriting can be recognized by the sensor or the controller/processor communicating with the sensor . Because the image sensor 410 and the spatial light modulator 302 share the same projection lens 404, the image captured by the image sensor is exactly the image projected by the projection lens 404, together with the users hand or Pen image. In this configuration, there is no need for any calibration between the two images, even if the projection distances are different or changed individually. The captured image information can be fed back to the image signal presented to the modulator 300 and the modulator 302 to change the display content or interact with the image projection system in any other way. Because the use of two spatial light modulators causes different images to be displayed on the main screen and the secondary screen/user screen, the interactive projector can be used to replace the monitor and keyboard functions. Alternatively, the user screen can be used as a writing pad, image capture device, touch panel, etc.

4A to 4D depict an image projection device 500 having a PBS cube 100 with polarization beam splitting elements only on the orthogonal diagonal surfaces. Two light sources 240 and 260 (which can be monochromatic or multi-color sources as discussed above with reference to FIG. 2) are used, together with four reflective spatial light modulators 350, 352, 354 positioned adjacent to each PBS cube face And 356 and two projection optical systems 406 and 408. To facilitate the understanding of the present invention, all figures show the same structure, but show different light paths.

In FIG. 4A, the light incident from the first light source 240 is incident on the surface 109 of the polarization beam splitter. The first reflective spatial light modulator 350 is positioned on the same side of the cube as the first incident light source 240. When the light reaches the PBS surface 109, the light with P polarization passes through the cube in a straight line and is incident on the second reflective spatial light modulator 352. The light with S polarization is reflected by the polarization beam splitter surface 109 and is reflected again by the polarization beam splitter surface 108 to the first reflective spatial light modulator 350.

The modulated light with opposite polarization is reflected by each reflective spatial light modulator 350, 352. Therefore, the P-polarized light leaves the reflective spatial light modulator 350, and pass the surface to the first group of projection optics 406. Similarly, the S-polarized light leaving the reflective spatial light modulator 352 is also reflected by the diagonal surface 108 of the PBS, and then reflected by the diagonal surface 109 toward the first set of projection optics 406.

In FIG. 4B, the light incident from the second light source 260 is incident on the surface 108 of the polarization beam splitter. The third reflective spatial light modulator 354 is positioned on the same side of the cube as the second incident light source 260. When the light reaches the PBS surface 108, the light with P polarization passes through the cube in a straight line and is incident on the fourth reflective spatial light modulator 356. The light with S polarization is reflected by the polarization beam splitter surface 108 and is reflected again by the polarization beam splitter surface 109 to the third reflective spatial light modulator 354.

The modulated light with opposite polarization is reflected by each reflective spatial light modulator 354,356. Therefore, the P-polarized light leaves the reflective spatial light modulator 354 and passes through the surface to the second set of projection optics 408. Similarly, the S-polarized light leaving the reflective spatial light modulator 356 is also reflected by the diagonal surface 109 of the PBS, and then reflected by the diagonal surface 108 toward the second set of projection optics 408.

In an exemplary embodiment, the projection device 500 is configured to project wide-screen 3D images. Generally, the left video content and the right video content are decoded by an image processor. Then, the left image and the right image are converted into color grayscale images (such as the left image of the P beam and the right image of the S beam) each in a specific polarization direction, and are used to modulate the respective spatial light modulators. Suitable filters such as a pair of passive polarizing lenses block undesired light beams for each eye, respectively. Therefore, when viewing the projection on the silver polarization preserving screen, the difference Create a three-dimensional image in the human brain when viewing the angle image. In this type of dual-LCoS projection system, the system efficiency can be maximized to 30%, and the efficiency in 3D mode is close to 45% compared with 2D mode brightness-both numbers are the best in existing projection technology.

For the embodiment in FIGS. 4A to 4C, the reflective spatial light modulator 350 and the reflective spatial light modulator 352 project the "left eye" image and the "left eye" image for the first 3-D image from the projection optics 406. The "right eye" image, while the reflective spatial light modulator 354 and the reflective spatial light modulator 356 project the "left eye" image and the "right eye" image for the second 3-D image from the projection optics 408. This combined projection is depicted in Figure 4C and Figure 4D. As in the embodiment of FIG. 2B, two 3-D images can be "stitched together" to form an appropriate polarizing filter that can be used, such as active or passive polarized glasses (but other filters can also be used) To view the wide-screen 3-D image in 3-D (see Figure 4E). The system is suitable for virtual reality game/movie applications. In addition to performing collage 3D projection, the system can also be used for two dual-brightness collage projections, which can be recycled by adding a pair of extra LCoS spatial light modulators.ofpolarized light.

The image projection device 600 of FIG. 5 replaces one of the reflective spatial light modulators in FIGS. 4A to 4D with an image sensor to create an interactive image device in a manner similar to the embodiment of FIG. 3 . In this embodiment, two images are displayed as in the embodiment of FIGS. 2A and 3. The image from the projection optics 408 will be the reflective spatial light modulator 354 and the reflective spatial light modulator 356 respectively projecting the "left eye" image and the "right eye" image of the 3-D image When viewing with the appropriate filter of the glasses). From anti The image of the reflective spatial light modulator 350 will be a 2-D image projected by the optical system 406. As in the embodiment of FIG. 3, the user interaction will be reflected back through the projection optics 406 and received by the image sensor 650 with optional IR filter. The user input can be used to allow the user to interactively change the 3-D image content or other commands through feedback from the sensor.

In FIGS. 6A to 6C, the image projector 700 uses two reflective spatial light modulators, two light sources, two projection optical systems, and uses two image sensors along the PBS cube 100. The S-polarized light from the light source 760 (with the polarizer 762) is incident on the diagonal PBS element 109 and is reflected toward the second diagonal PBS element 108 toward the reflective spatial light modulator 750. The P-polarized light reflected from the modulator 750 is projected on the secondary position via the projection optics 706. Similarly, the S-polarized light from the light source 770 (with the polarizer 772) is incident on the diagonal PBS element 108 and is reflected toward the second diagonal PBS element 109 toward the second reflective spatial light modulator 752. The P-polarized light reflected from the modulator 752 is projected to the main viewing position through the projection optics 708. User interactions with images at the primary viewing position or secondary viewing positions are received by the respective image sensors 620 and 610 to allow the user to input information to the system that can be used to change the current and future image display. For ease of understanding, each of FIGS. 6A to 6C shows different transmitted and reflected light paths.

7A and 7B illustrate the details of the light path of the integrated PBS (100) used in various embodiments of the present invention. The integrated PBS (100) includes optical features for enhancing brightness or image contrast. In FIG. 7A, two LCoS modulators (801, 802) are used, each of which is placed on one half of the outer surface of the optical cube 100 on two opposite sides. The light input is polarized by the first The surface 805 of the vibrating beam splitter is divided into P beam and S beam; 90% of the P beam and 1% of the S beam will pass through the first PBS front surface 805; 99% of the S beam and 10% of the P beam will be reflected to the first PBS A second PBS front surface 806; then, 0.01% of the S beam and 81% of the P beam will pass through the first and second PBS front surface 806 to illuminate the LCoS1 801. And 99% of the S beam and 10% of the P beam will be reflected by the front surface 807 of the second second PBS to illuminate the LCoS2 802. With this design, for the LCoS1 801 and LCoS2 802 paths, the optical contrast is enhanced from 90:1 to more than 1000:1. The analyzer surface 808 is used to combine the two paths and project an image through the projection lens 809.

In order to further enhance the contrast, the P polarization analyzer 903 can be added to the frame as depicted in FIG. 7B, and the top and bottom two frames are split into two parts, where in two of the split parts A P pass-through analyzer is coated or attached between the surfaces and then joined together (Figure 7B). The contrast ratio after passing through the P analyzer is at least 100:1. After the front surface of the second PBS, the contrast ratio will be 1000:1 or more on LCoS2; the P beam leakage to the S beam path can be minimized; and the P beam leakage to the S beam projection system after LCoS1 can also be minimized change. As a result, the system contrast can be increased to 300:1. The contrast ratio also depends on the contrast of the LCoS panels 901 and 902 themselves. The P polarization analyzer 903 can be coated with polarization beam splitter elements, grating microstructures or MOF films or other materials that can split light into two orthogonal polarization directions.

Although the foregoing invention has been described in terms of various embodiments, these embodiments are not limitative. Generally, those who are familiar with this technology will understand many changes and modifications. It is believed that these changes and modifications are included in the scope of the following patent applications Inside.

<p>100Polarizing beam splitter cube/integrated polarizing beam splitter/</p><p>102Surface coating</p><p>103</p><p>104</p><p>105</p><p>106</p><p>107Mirror coating/mirror surface/reflector</p><p>108Polarization beam splitter surface</p><p>109Polarization beam splitter surface</p><p>200Projection device</p><p>210Light source</p><p>240Light source</p><p>260Light source</p><p>300First reflective spatial light modulator</p><p>302Second reflective spatial light modulator</p><p>310Incident light source optics</p><p>350Reflective spatial light modulator</p><p>352Reflective spatial light modulator</p><p>354Reflective spatial light modulator</p><p>356Reflective spatial light modulator</p><p>400Projection device</p><p>402Projection optics</p><p>404Projection optics</p><p>406Projection optics</p><p>408Projection optics</p><p>410Image Sensor</p><p>500Image Projection Device</p><p>600Image Projection Device</p><p>610Image Sensor</p><p>620Image Sensor</p><p>650Image sensor</p><p>700Image Projector</p><p>706Projection optics</p><p>708Projection optics</p><p>750Reflective spatial light modulator</p><p>752Reflective spatial light modulator</p><p>760Light source</p><p>762Polarizer</p><p>770Light source</p><p>772Polarizer</p><p>801Reflective spatial light modulator</p><p>802Reflective spatial light modulator</p><p>805Polarization beam splitter surface</p><p>806The front surface of the polarizing beam splitter</p><p>807Front surface of polarizing beam splitter</p><p>808Analyzer surface</p><p>809Projection lens</p><p>901Liquid Crystal Over Silicon (LCoS) Panel</p><p>902Liquid Crystal On Silicon (LCoS) Panel</p><p>903P Polarization Analyzer</p>

Figures 1A to 1C depict a polarizing beam splitter cube structure used in the image projection device of the present invention; Figures 2A to 2C depict a light source, two reflective spatial light modulators and two projection optical systems Image projection device; Figure 3 depicts the image projection system in Figure 2A with an image sensor added; Figures 4A to 4E depict images with two light sources, four reflective spatial light modulators and two projection optical systems Projection device; Figure 5 depicts an image projection device with two light sources, three reflective spatial light modulators, two projection optical systems and an image sensor; Figures 6A to 6C depict two polarized light sources, two An image projection device with a reflective spatial light modulator, two projection optical systems, and two image sensors; and Figures 7A to 7B depict optional contrast enhancement features that can be used in the image projection device of the present invention.