TWI422999B - Holographic display device, manufacturing method thereof and method of generating holographic reconstruction - Google Patents

Description

Full-image display device, method of manufacturing the same, and method for generating holographic reconstruction

The present invention is a holographic display device in which an image hologram generated by a computer is encoded, and the device includes at least one Magneto-optical Spatial Light Modulator. This device produces a three-dimensional holographic reconstruction.

Computer-generated video holograms (CGHs) are encoded by one or more Spatial Light Modulators (SLMs); spatial light modulators include controllable components. . These components encode the hologram values based on the image hologram to achieve the purpose of modulating the amplitude and phase of the light. The computer-generated image hologram can be calculated, for example, by coherent ray tracing, by simulating interference between the reflected light and the reference wave, or by Fourier or Fresnel conversion. An ideal spatial light modulator is a value that can represent any complex number, that is, the phase and amplitude of the incoming light wave are separately controlled. However, a typical spatial light modulator can only control one of the amplitudes or phases, with adverse effects that affect the other. There are currently several different ways to modulate the amplitude and phase of light, such as with an electronically addressed liquid crystal spatial light modulator, an optically addressed liquid crystal spatial light modulator, a micromirror device, or an acousto-optic modulator. The modulation of light can be spatially contiguous or composed of individual addressable elements, which can be one or two dimensional, binary, multi-level or continuous. Magneto-optical spatial light modulators (MOSLM) are one of the known types of spatial light modulators. In a magneto-optical spatial light modulator, the current in the coil on the display controls the magnetic field, which in turn affects the biased state of the polarized light propagating through the display pixels. Therefore, the magneto-optical spatial light modulator is also a kind of electronic address space light modulator.

In the present invention, the proper noun "encoding" means providing a spatial light modulator control value to encode the hologram such that the three-dimensional scene can be reconstructed by the spatial light modulator. The term "space light modulator coded hologram" means that the hologram is encoded on a spatial light modulator.

Compared with the pure automatic stereo display panel, the observer can observe the optical reconstruction of the wavefront of the three-dimensional scene through the image hologram. The three-dimensional scene is reconstructed in a space that extends between the observer's eye and the spatial light modulator or even after the spatial light modulator. The spatial light modulator can also be encoded using an image hologram such that the observer can observe the reconstructed three-dimensional scene object before the spatial light modulator, while other objects are observed on or behind the spatial light modulator.

The elements of the spatial light modulator are those that are more optically transmissive, the radiation of which at least can cause interference at a defined location and have a coherence length of more than a few millimeters or more. This will allow holographic reconstruction to have sufficient resolution in at least one dimension. This type of light will be referred to as "full dimming".

In order to ensure sufficient time homology, the spectrum emitted by the source must be limited to a suitably narrow wavelength range, ie it must be close to a single color. The spectral bandwidth of high-brightness light-emitting diodes (LEDs) is sufficiently narrow to ensure temporal homology of holographic reconstruction. The diffraction angle on the spatial light modulator is proportional to the wavelength, meaning that only one monochromatic source will produce a significant reconstruction of the target point. A wide spectrum will result in a wide target point and a fuzzy target reconstruction. The spectrum of the laser source can be treated as a single color. The spectral linewidth of a single color light-emitting diode (LED) is sufficiently narrow to aid in better reconstruction.

Spatial coherence is related to the lateral width of the light source. Conventional light sources, such as light-emitting diodes (LEDs) or cold cathode light-emitting lamps (CCFLs), can also meet these needs if their emitted light passes through a narrow gap. Laser light source Considered as being emitted from a diffraction-limited point source, depending on the purity of the form, a significant reconstruction of the target will be produced, ie each target point is reconstructed as a point of diffraction limitation.

The light produced by the spatially non-coherent light source extends laterally and causes the reconstruction target to be blurred. The ambiguity is determined by the broad size of the target point reconstructed at a given location. In order to use a spatially non-coherent light source for hologram reconstruction, a compromise must be found between brightness and the use of aperture to limit the lateral width of the source. Smaller sources will give better spatial coherence.

A linear light source can be regarded as a point source if viewed from a viewpoint perpendicular to the longitudinal extension. Therefore, the light wave can propagate in the same direction in the same direction, and it is not the same in all other directions.

In general, a hologram is a holographic reconstruction of the scene by coherent super-overlap of the waves in the horizontal and vertical directions. The above image hologram is called a full parallax hologram. The reconstructed object can be thought of as a moving parallax in the horizontal and vertical directions, just like a real object. However, a larger viewing angle is required to have a high resolution in the horizontal and vertical directions of the spatial light modulator.

In general, the demand for spatial light modulators is reduced by being limited to holograms with only horizontal parallax (Horizontal-Parallax-Only, HPO). The holographic reconstruction only occurs in the horizontal direction, and there is no holographic reconstruction in the vertical direction. This will result in a reconstructed object with horizontally moving parallax. The perspective on the vertical movement does not change. An hologram with only horizontal parallax requires that the spatial light modulator will have a lower resolution in the vertical direction than the full parallax hologram. It is also possible to use a hologram with only Vertical-Parallax-Only (VPO), but it is rare. A holographic reconstruction occurs only in the vertical direction, producing a reconstructed object with a vertical moving parallax. There is no moving parallax in the horizontal direction. For the left and right eyes, different perspectives must be produced separately.

A reference is made to WO 2004/044659 (US2006/0055994) for reference. A device for reconstructing a three-dimensional scene by diffracting with sufficient dimming; the device includes a point source or a linear source, a lens for focusing light, and a spatial light modulator. Compared to the conventional holographic display, the spatial light modulator reconstructs the three-dimensional scene in at least one "virtual observer window" in the transmission mode (for the description of the virtual observer window and related techniques, please refer to Annexes 1 and 2). Each virtual observer window is placed close to the observer's eyes and is limited in size, so the virtual observer window is in a single diffraction class, so each eye can see the three-dimensional scene in the conical reconstruction space. Complete reconstruction, conical reconstruction space is extended between the surface of the spatial light modulator and the virtual observer window. In order for the hologram reconstruction to be undisturbed, the size of the virtual observer window must not exceed the periodic interval of the reconstructed diffraction stage. However, this must be at least large enough to allow the observer to see a complete reconstruction of the 3D scene via the window. The other eye can be viewed through the same virtual observer window or a second virtual observer window generated by the second source. At this point, the typically larger visible area is limited to the locally placed virtual observer window. The conventional solution is to refine the large area created by the high resolution of the surface of the conventional spatial light modulator in a miniaturized manner, so that the size can be reduced to match the size of the virtual observer window. This will result in a smaller diffraction angle for geometric reasons and the resolution of the current spatial light modulator that is sufficient to achieve instant holographic reconstruction through a general consumer level computing device.

However, this can suffer from the frame rate produced by the hologram display, especially in the case of multiple display viewers. In the omni-image generating method described in WO 2004/044659 (US2006/0055994), a plurality of virtual observer windows are employed. If the virtual observer window is in the observer's eye position, the reconstruction target will be visible. A virtual observer window is required for each eye of each observer. If virtual observer window and color red (R), green (G) and blue If color (B) is generated sequentially, a high frame rate is required. “Sequence” means that red, green and blue light is turned on and off in a sequential manner, so for a pixel on a spatial light modulator, the same components can be used to encode red, green and blue in sequence. Light. In order to avoid the feeling of flicker, the frame rate for each eye needs to be at least 30 Hz. As an example, for example for 3 observers, a frame rate of 30 Hz * 2 eyes * 3 observers * 3 colors = 540 Hz is required. This is much faster than the frame speed of a liquid crystal based spatial light modulator. Even for a single observer, a frame tempo of 180 Hz may be the limit that current liquid crystal spatial light modulator technology can achieve - some display products that rapidly transform images will appear. Known fast micro-electromechanical systems (MEMS)-space optical modulators do not provide high resolution phase modulation. With regard to these techniques, the characteristic switching time is about 10 ms for liquid crystal and about 10 μs for a micro-motor system. Therefore, the conventional device has a great difficulty in displaying a holographic image to a plurality of observers in full-complex hologram coding, especially when the image is colored. With regard to a single observer example, there would be benefits to faster frame rates than would be possible with liquid crystal technology, such as applications with fast moving activities such as video games, watching sports or action movies, or in the military. Applications.

Space light modulators that allow for individual amplitude and phase modulation (including the case of series paired spatial light modulators) will be more suitable for use in holographic displays. The complex-valued hologram has better reconstruction quality and higher brightness than the pure amplitude or pure phase hologram. Conventional Faraday effect magneto-optical spatial light modulators (MOSLMs) are known, but they only modulate the amplitude of the transmitted light and are not used to generate a hologram. Such spatial light modulators have been published by Panorama Labs of Rockefeller Center, 1230 Avenue of the Americas, 7th Floor, New York, NY 10020 USA (www.panoramalabs.com), for example with reference to WO2005/076714A2, while others Magneto-optical spatial light modulators of this type are also known.

Thus, for holographic display devices, as well as for spatial light modulators in holographic display devices, it would be desirable to be able to provide high frame rates, and preferably to independently encode phase and amplitude data.

In a first aspect, a hologram display device is provided, the hologram display device comprising at least one magneto-optical spatial light modulator.

The holographic display device may include a first magneto-optical spatial light modulator and a second magneto-optical spatial light modulator, and the first and second magneto-optical spatial light modulators may encode an hologram, and the device may generate the full image Like reconstruction. The hologram display device allows the first magneto-optical spatial light modulator and the second magneto-optical spatial light modulator to modulate the amplitude and phase of the hologram pixel array in a controlled and independent manner. The holographic display device can comprise a tight combination of the first magneto-optical spatial light modulator and the second magneto-optical spatial light modulator, which can be used for sequentially and closely modulating the amplitude and phase of the light such that the amplitude is The complex value formed by the phase can be encoded in the transmitted light one by one.

The holographic display device can include a close combination of a magneto-optical spatial light modulator and a fully coherent compact light source, such a combination capable of producing a three-dimensional image with appropriate illumination.

The hologram display device may include a large-magnification three-dimensional image display device having a close combination of one or two magneto-optical spatial light modulators and having a target holographic reconstruction.

The hologram display device can comprise a tight combination of one or two magneto-optical spatial light modulators, which can also be used as a projector.

The hologram display device can have at least one spatial light modulator to encode the hologram and the device will produce a holographic reconstruction.

The hologram display device can be a device that modulates light using a Faraday effect. The hologram display device can be a device that utilizes a magneto-photonic crystal to achieve a Faraday effect. The holographic display device can be a device that achieves a Faraday effect by doped glass fibers. The hologram display device can be a device that uses a magneto-optical film to achieve the Faraday effect.

The holographic display device can be a device that can observe holographic reconstruction through its virtual viewer window.

The holographic display device can be a device in which a virtual viewer window can be tiled with space or time multiplex.

The holographic display device can be a device in which the display is operable to temporally re-encode the hologram on the medium containing the hologram for the observer's left eye followed by the right eye.

The holographic display device can be a device in which the display is operable to re-encode all of the temporally sequential media on the medium containing the hologram for the left and right eyes of two or more viewers. Like a picture.

The hologram display device can be a device in which the display has a beam steering or beam splitter element.

The hologram display device can be a device in which the display has a computer layer in the display.

The hologram display device can be a device in which the display has eye tracking.

The hologram display device can be a device in which the display is illuminated with a backlight and a microlens array. The microlens array provides local homology over a small area of the display, which is the only part of the display that is used to encode the reconstructed object Information about a given point. This display can include a reflective polarizer. This display can include a 稜鏡 optical film.

The hologram display device can have a light emitting diode as its light source.

This hologram display device can be a television. This hologram display device can be a screen. The hologram display device can be portable.

In another aspect, a method of making a display device is provided, comprising the steps of obtaining a glass substrate and continuously printing on the substrate or otherwise producing a magneto-optical spatial light modulator layer.

In another aspect, a method of generating holographic reconstruction is presented, including the steps of using the display device described above.

In another aspect, a holographic display device comprising a magneto-optical spatial light modulator is provided, the spatial light modulator encoding a hologram and the device producing a holographic reconstruction. This hologram display device can be a television. This hologram display device can be a screen. The hologram display device can be a notebook computer. This hologram display device can be a mobile phone. This holographic display device can be a personal digital assistant. This holographic display device can be a digital walkman. This holographic display device allows the Faraday effect to modulate light. The holographic display device enables the Faraday effect to modulate light, and the Faraday effect can be achieved by a magnetic photonic crystal. This holographic display device allows the Faraday effect to modulate light, and the Faraday effect can be achieved by doping glass fibers. The holographic display device allows the Faraday effect to modulate light, and the Faraday effect can be achieved by a magneto-optical film. The hologram display device can be illuminated using a backlight and a microlens array. The backlight of the hologram display device may include at least one reflective polarizer to provide a linearly polarized state of light. The backlight of the hologram display device can include at least one reflective polarizer to provide a circularly polarized state of light. The micro-transparent array of the hologram display device provides local coherence on a small area of the display, which is the only part of the display that is used to encode the reconstructed object Information about a given point. The spatial light modulator of this hologram display device provides phase encoding. The spatial light modulator of this hologram display device provides amplitude encoding. The holographic reconstruction of this holographic display device can be viewed via a virtual observer window. The virtual observer window of the hologram display device can be laid out using space or time multiplex. The hologram display device can be steerable such that omni-directional reconstruction can be correctly observed only when the observer's eye is close to the image plane position of the light source. The holographic display device allows the size of the reconstructed three-dimensional scene to be a function of the size of the hologram medium, which can be defined by the medium with the hologram and the virtual observer window that can be viewed to reconstruct the three-dimensional scene. Anywhere within the volume. The hologram display device can encode an hologram that can include an area having information needed to reconstruct a single point of the three-dimensional scene, which can be seen from a defined viewing position; this area (a) coded about reconstruction The information of a single point in the scene, (b) is the only area in the hologram that encodes the information, and (c) the size is limited to form part of the overall hologram, the size needs to be higher The multiple reconstructions produced by the diffraction level for that point are not visible by the defined viewing position. The holographic display device can be operable to temporally re-encode the hologram in time for the viewer's left eye followed by the right eye on the medium containing the hologram. The holographic display device can be operable to re-encode the hologram in time on the medium containing the hologram for the left eye followed by the right eye of two or more viewers. This holographic display device allows the hologram to be reconstructed into a Fresnel transform of the hologram, rather than a Fourier transform of the hologram. The hologram display device can encode a hologram that can be generated by determining a wavefront that is close to the observer's eye position, which can be generated by the real version of the reconstructed object. The hologram display device can have a 稜鏡 element to provide beam steering. This hologram display device can have a computer layer in the display. This hologram display device can have eye tracking.

In another aspect, a method of generating holographic reconstruction is presented, including the steps of using the display device described above.

In another aspect, a holographic display device including a first magneto-optical spatial light modulator and a second magneto-optical spatial light modulator is provided, the first and second magneto-optical spatial light modulators encoding the hologram Figure, and the device will produce a holographic reconstruction. The hologram display device can be a device in which the first and second magneto-optical spatial light modulators modulate the amplitude and phase of the hologram pixel array in a controlled and independent manner. The hologram display device can be a device in which one magneto-optical spatial light modulator modulates the amplitude of the full image pixel array and the other magneto-optical spatial light modulator modulates the phase of the full image pixel array. The holographic display device can be a device in which a magneto-optical spatial light modulator modulates a first combination of amplitude and phase of a full-image pixel array, and another magneto-optical spatial light modulator modulates an hologram A second different combination of amplitude and phase of the pixel array. The hologram display device can be a device in which light propagating through the device first encodes its phase and then encodes its amplitude. This hologram display device can be a television. This hologram display device can be a screen. The hologram display device can be a notebook computer. This hologram display device can be a mobile phone. This holographic display device can be a personal digital assistant. This holographic display device can be a digital walkman. The hologram display device can be a device in which each magneto-optical spatial light modulator uses a Faraday effect to modulate light. The hologram display device can be a device in which the device uses the Faraday effect to modulate light, and in at least one magneto-optical spatial light modulator, the Faraday effect is achieved using a magnetic photonic crystal. The holographic display device can be a device in which the device uses the Faraday effect to modulate light, and in at least one magneto-optical spatial light modulator, the Faraday effect is achieved using doped glass fibers. The hologram display device can be a device in which the device uses the Faraday effect to modulate light, and in at least one magneto-optical spatial light modulator, the Faraday effect is achieved using magneto-optical wax. This whole The image display device can be a device in which the magneto-optical spatial light modulators are separated by a separation layer. The holographic display device can be a device in which the spacer layer is sufficiently thin to avoid adverse effects of the electromagnetic field of one magneto-optical spatial light modulator on the performance of another magneto-optical spatial light modulator. The holographic display device can be a device in which the spacer layer also provides mechanical support for at least one magneto-optical spatial light modulator. The hologram display device can be a device in which the spacer layer is of a rating lower than or equal to 10 microns to 100 microns. The hologram display device can be a device in which the display device encodes an hologram and is capable of producing a hologram reconstruction. The hologram display device can be a device in which the display is illuminated with a backlight and a microlens array. The hologram display device can be a device in which the backlight includes at least one reflective polarizer to provide a linearly polarized state of light. The hologram display device can be a device in which the backlight includes at least one reflective polarizer to provide a circularly polarized state of light. The holographic display device can be a device in which the microlens array provides local homology over a small area of the display, which is the only portion of the display that encodes information used at a given point of the reconstructed object. The holographic display device can be a device in which holographic reconstruction can be observed via a virtual viewer window. The hologram display device can be a device in which the virtual viewer window can be laid out in a space or time multiplex. The hologram display device can be a device in which omni-directional reconstruction can be correctly observed only when the observer's eyes are close to the image plane position of the light source. The holographic display device can be a device in which the size of the reconstructed three-dimensional scene is a function of the size of the hologram medium, and the reconstructed three-dimensional scene can be located in the medium of the hologram and the virtual view of the reconstructed three-dimensional scene. Anywhere within the volume defined by the observer window. The hologram display device can be a device in which the display encodes a hologram that contains an area having information needed to reconstruct a single point of the three-dimensional scene from a defined viewing position. Seen; this area (a) encodes information about a single point in the reconstructed scene, (b) is the only area in the hologram that encodes that information, and (c) the size is limited to form a whole As part of the diagram, the size is such that the multiple reconstructions produced by the higher diffraction level for that point are not viewed by the defined viewing position. The holographic display device can be a device in which the display is operable to temporally re-encode the hologram in time for the viewer's left eye followed by the right eye on the medium containing the hologram. The holographic display device can be a device in which the display is operable to temporally re-encode sequentially on the medium containing the hologram for the left and right eyes of two or more viewers Full picture. The hologram display device can be a device in which the display is operable such that the hologram is reconstructed into a Fresnel transform of the hologram, rather than a Fourier transform of the hologram. The holographic display device can be a device in which the display encodes a hologram that can be generated by determining a wavefront near the observer's eye position, which can be generated by the actual version of the reconstructed object. The hologram display device can be a device having a haptic element therein to provide beam steering. The hologram display device can be a device having a computer layer in one of the displays. The hologram display device can be a device with eye tracking.

In another aspect, a method of fabricating a hologram display device is provided, comprising: obtaining a glass substrate, and continuously printing on the substrate or otherwise generating a first magneto-optical spatial light modulator and a second magneto-optical spatial light The steps of the modulator layer.

In another aspect, a method of generating holographic reconstruction is presented, including the steps of using the display device described above.

In another aspect, a close combination of a magneto-optical spatial light modulator and a coherent compact light source is provided that is capable of producing a three-dimensional image under appropriate illumination conditions. This compact combination can be a device in which imaging light is not required learn. This tight combination can be a device in which the total thickness of the device components is less than 3 cm. This tight combination can be a device in which a soft aperture provides a tightly coupled pixel.

On the other hand, a close combination of two magneto-optical spatial light modulators is provided, which can be used to sequentially and closely modulate the amplitude and phase of the modulated light so that the complex values formed by the amplitude and the phase can be pixel by pixel. The way to encode in the transmitted light. This tight combination can be a device in which imaging optics need not be provided. This tight combination can be a device in which the total thickness of the device components is less than 3 cm. This tight combination can be a device in which there are pixels of a flexible aperture providing device. This tight combination can be a device in which two magneto-optical spatial light modulators are directly connected or bonded together by arranging pixels. This tight combination can be a device in which the spacing of the two magneto-optical spatial light modulators is on the order of less than or equal to 10 microns to 100 microns. This tight combination can be a device in which the diffraction of light from one magneto-optical spatial light modulator through another magneto-optical spatial light modulator is in the form of a Fresnel diffraction method. Rather than using far-field diffraction. This compact combination can be a device in which there is a lens array between two magneto-optical spatial light modulators such that each lens images the pixels of the first spatial light modulator to the second spatial light modulator On the corresponding pixel. This tight combination can be a device in which the aperture width of the first magneto-optical spatial light modulator pixel is such that pixel crosstalk can be minimized. This tight combination can be a device in which the first magneto-optical spatial light modulator pixel has a wide aperture such that it can pass the pixel crosstalk to the second magneto-optical spatial light modulator pixel, with Fu Lang and Fei The diffraction method is minimized. This tight combination can be a device in which a fiber optic panel is used to image the pixels of the first magneto-optical spatial light modulator onto the pixels of the second magneto-optical spatial light modulator.

In another aspect, a large magnification 3D image display device component is provided that includes a close combination of one or two magneto-optical spatial light modulators and has a holographic reconstruction of the target. The display device component can comprise a close combination of one or two magneto-optical spatial light modulators and a sufficiently homogenous compact light source. The display device component can include a close combination of one or two magneto-optical spatial light modulators and a sufficiently homogenous compact source to enable such a combination to produce a three-dimensional image. The display device component can comprise a tight combination of one or two magneto-optical spatial light modulators and a sufficiently homogenous compact light source in which the light source is magnified 10 to 60 times via the lens array. The display device component can comprise a compact combination of one or two magneto-optical spatial light modulators and a sufficiently homogenous compact light source, wherein at least one of the magneto-optical spatial light modulators is disposed within 30 mm of the light source. The display device component can include a tight combination of one or two magneto-optical spatial light modulators and a sufficiently homogenous compact light source such that such a combination produces a three-dimensional image that can be viewed through a virtual viewer window. The display device component can be an element in which the virtual viewer window is a diffractive class that limits the Fourier spectrum of information encoded in the spatial light modulator. The displayed virtual observer window can be either traceable or untrackable. The displayed virtual observer window can be multiplexed in space or time to piece together a number of virtual observer windows into an enlarged virtual observer window. The display device component can comprise a tight combination of one or two magneto-optical spatial light modulators and a sufficiently homogenous compact light source, and wherein the light source in the array of light sources has only partial spatial homology. This display device component can be included in a personal digital assistant. This display device component can be included in a mobile phone. The calculation of the hologram image encoded on the spatial light modulator can be performed by an external coding unit, and then the display data is transmitted to the device component to display the three-dimensional image generated by the hologram.

In another aspect, a method of making a hologram display device is provided, comprising taking a glass substrate and continuously printing on the substrate or otherwise generating one or a step of two magneto-optical spatial light modulator layers, the device comprising a large-magnification three-dimensional image display device component, the large-magnification three-dimensional image display device component being tight by one or two magneto-optical spatial light modulators The combination is composed and has a holographic reconstruction of the target.

In another aspect, a method of generating holographic reconstruction is presented that includes the steps of using the display device components described above.

The "space light modulator coded hologram" means that the hologram is encoded on the spatial light modulator.

Various embodiments will be described below. A. Full-image display device with magneto-optical spatial light modulator

This embodiment provides a holographic display device having a magneto-optical spatial light modulator that is capable of producing a three-dimensional image under appropriate illumination conditions. This display can be illuminated by multiple sources or a single source. The holographic display device can be used on televisions, screens, notebook computers, mobile phones, personal digital assistants, digital walkmans, or any other device having a display.

This embodiment relates to a spatial light modulator for modulation of light, such as amplitude, phase or modulation of amplitude and phase combinations. In particular, this is about a spatial light modulator that is based on the use of the Faraday effect. This spatial light modulator can be used in a hologram display.

According to the application of the magnetic field in the direction of light propagation, the Faraday effect can manifest itself as the rotation of linear polarization in the medium. It is the quantitative description of this equation α=V L H (1) Where α is the angle of polarization rotation, V is the Verdet constant, L is the length of the medium, and H is the magnetic field strength. The Faraday effect is produced by the anisotropy introduced by the magnetic field. The magnetic field is an axial vector, that is, sensitivity to the handedness of rotation. Therefore, the left and right circular polarizations are no longer in a degraded state, they experience different refractive indices in the medium and experience different phase shifts. Because linear polarization is composed of left-handed and right-handed circular polarization, if these components have different phase shifts, when these circular components are combined into linear polarization, it will lead to linear polarization angle rotation. .

Generally, the Feld constant V is small, so a significant rotation angle α is a magnetic field H that requires a long length L or a high. The Faraday effect is significantly increased in a magneto-photonic crystal comprising a magneto-optical layer stack. For spatial light modulators, this helps the use of the Faraday effect in thin structures with small magnetic fields. This is described, for example, from the Internet "A Presentation for Investors" by Panorama Labs of Rockefeller Center, 1230 Avenue of the Americas, 7th Floor, New York, NY 10020 USA (www.panoramalabs.com) (This file is listed here as a reference). This file is available on the web.archive.org website.

As shown in Figure 3, Panorama Labs has published a spatial light modulator using the Faraday effect. It contains magnetic photonic crystals, input and output polarizers, and coil arrays. For each pixel of a spatial light modulator with a pixel pitch of 16 μm, there is a corresponding coil. The magnetic photonic crystal is composed of a stack of a plurality of magneto-optical layers, and the plurality of magneto-optical layers can enhance the Faraday effect compared to a single layer. Regarding the application of current, the coil generates a local magnetic field in each pixel, causing the linearization of the light passing through the pixel to initiate rotation. The output polarizer only transmits a specific polarization angle. therefore, The transmittance of each pixel can be modulated by the current in the coil. FIG. 3 shows one pixel of a spatial light modulator including a polarizer 301, a magnetic photonic crystal (MPC), a coil 303, and an analyzer 302. The constant input intensity p0 is modulated to depend on the output intensity function p(t) for a given time (t).

Compared to liquid crystal or micro-motor system-space light modulators, the Faraday effect space light modulator has the advantage of fast response time. Panorama Labs has published a Faraday effect space modulator with a 20ns response time, which is much faster than a liquid crystal (approximately 10ms) or a micro-motor system (approximately 10μs) spatial light modulator. The magneto-optical spatial light modulator can be used for electronic holographic display. In one method of holographic display, a virtual observer window (VOW) is generated. If the virtual observer window is in the observer's eye position, the reconstructed target will be visible. A virtual observer window is required for each eye of each observer. If the virtual viewing real window and the color red (R), green (G), and blue (B) are sequentially generated, a higher frame rate is required. To avoid flicker, the frame rate for each eye needs to be at least 30 Hz. As an example, for example for 3 observers, a frame rate of 30 Hz * 2 eyes * 3 observers * 3 colors = 540 Hz is required. This will be much faster than the frame speed of the LCD-space light modulator. Known fast micro-motor systems - spatial light modulators do not provide high resolution phase modulation. A spatial light modulator that modulates amplitude and phase is more suitable for use in electronic holographic displays. The complex-valued hologram has better reconstruction quality and higher brightness than the pure amplitude or pure phase hologram. In Figure 3, the only significant effect of the Faraday Effect Space Modulator published by Panorama Labs is its modulation of transmitted light amplitude. In addition, the Faraday effect space light modulator published by Panorama Labs in Figure 3 does not illuminate the coherent light to promote the generation of three-dimensional images.

Figure 1 is an embodiment. 10 is a lighting device for providing a photo of a flat area It is clear that the illumination is sufficiently homogenous to be able to produce a three-dimensional image. An example for a large-area image hologram is presented in US 2006/250671, which is incorporated herein by reference in its entirety in its entirety. A device like 10 may take the form of a white light source array, such as a cold cathode fluorescent lamp or a white light emitting diode that is incident on a focusing system, wherein the focusing system can be tight, Such as a lenticular array or a microlens array. Alternatively, the light source for 10 may be composed of red, green, and blue lasers, or may be composed of red, green, and blue light emitting diodes that emit sufficient tonal light. However, compared to laser sources, non-laser sources (eg, light-emitting diodes, organic light-emitting diodes, cold cathode fluorescent lamps) having sufficient spatial coherence are preferred. Laser sources have some disadvantages, such as laser speckles on holographic reconstruction, relatively expensive, and may damage the eyes of a holographic display viewer or a holographic display assembly. Security issue.

The element 10 may comprise one or two xenon optical films for increasing the brightness of the display: such a film is known, for example, as described in US 5,056,892 and US 5,919,551.

The hologram generator 15 can be sized to range from a screen size (or smaller) that is applied to a mobile phone secondary screen to a one meter screen size for large indoor displays (or Bigger). Thus, the thickness of all of elements 10-14 can range from one millimeter, or even less, up to tens of centimeters, or even more (e.g., in the case of large indoor displays). Element 11 is a polarizing element or a set of polarizing elements. An example of this is a linear polarizer. Another example is a reflective polarizer that transmits a linearly biased state and reflects an orthogonal linearly biased state - such a sheet is known, for example, as described in US 5,828,488. Another example is a reflective polarizer that transmits a circularly polarized state and reflects orthogonal circles. Shape-biased state - such sheets are known, for example as described in US 6,181,395. Element 12 may be constructed of a color filter array such that pixels of colored light (e.g., red, green, and blue light) are directed toward element 13, although a color filter is not required if a colored light source is used. Element 13 is a magneto-optical spatial light modulator. In its simplest form, element 13 is an array of conductive material coils, each used to independently control the magnetic field in the display that experiences light traversing its corresponding pixel. Such control can be assisted by light passing through a medium having a significant Feld constant V such that linear polarization can achieve significant rotation a as it passes through the medium, as described in equation (1). This medium can be in the form of a doped fiberglass cylinder, or a similar shape, as described in US 2005/0201705. This medium can also be in the form of a magneto-optical film, as described in WO 2005/122479 A2, or in the form of a layer of magnetic photonic crystals. Light exiting the medium will then pass through the photo-biasing layer 14, such as a linear polarizer.

If the element 11 is a reflective polarizer for a circularly polarized state of light, circularly polarized light will be transmitted from the element 11 to the element 12, and the orthogonally polarized light will be reflected back to the element 10 to provide a possible Recycling, and during this time its biasing may change to the state transmitted by element 11. In this example, the polarizer 14 after the element 13 is composed of a quarter wave plate for converting the circularly polarized light into a linear bias, followed by a linearly polarized sheet. The effect of a quarter wave plate may exceed the visible spectrum, such as that described in US 7,054,049; it also has other quarter wave plates whose known effects exceed the visible spectrum. The linearly polarized sheet 14 can be set at an azimuthal rotation angle such that when no current flows through the array coil, H is zero and extends throughout the array of pixels, so the polarization state does not change for all pixels of the array, and the display It is a dark state. Other settings can be obtained from conventional techniques. The current in the array coil can be changed pixel by pixel The state, thereby enabling images (eg, color images) to be displayed. Wherein, the optical input polarization state to the magneto-optical spatial light modulator is a simple circular polarization state, and the current in the coil enables the phase to be encoded in a circularly polarized state, as described elsewhere in this case. content. Such phase encoding allows a hologram with phase information to be encoded thereon.

If the element 11 is a reflective polarizer for the linearly polarized state of light, the linearly polarized light will be transmitted from the element 11 to the element 12, and the orthogonally polarized light will be reflected back to the element 10 to provide a possible recovery, And during this time its biasing may change to the state transmitted by the component 11. In this example, the polarizer 14 after the element 13 is a linearly polarized sheet. The linearly polarized sheet 14 can be set at an azimuthal rotation angle such that when no current flows through the array coil, H is zero and extends throughout the array of pixels, so the polarization state does not change for all pixels of the array, and the display It is a dark state. Other settings can be obtained from conventional techniques. The current in the array coil can change the polarization state one pixel by pixel, thereby allowing images (eg, color images) to be displayed. Among them, the optical input polarization state to the magneto-optical spatial light modulator is a purely linearly biased state, and the current in the coil enables the amplitude to be encoded in the biased state, as described elsewhere in this case. Such amplitude coding allows an hologram with amplitude information to be encoded thereon.

In Fig. 1, a viewer located at a distance 16 from the apparatus including the hologram generator 15 can view the three-dimensional image from the direction of 15. The elements 10, 11, 12, 13 and 14 can be configured to be physically connected (realally connected), each forming a layer of the structure such that the entirety is a single, uniform object. Physical connections can be direct. Or indirect, if there is a thin intermediate layer, a film covering between adjacent layers is formed. Physical connections can be limited to small areas to ensure proper inter-arrangement, or can extend to larger areas, even the entire surface of the layer. Physical connections can be glued by layers This is accomplished, for example, by using optically transmissive adhesives to form a compact hologram generator 15, or by any other means (see the Summary Manufacturing Procedures section). However, if the element 15 is not particularly required to be tight, some or all of the elements 10, 11, 12, 13 and 14 can be separated.

Figure 4 is a side view of a conventional technique showing three focusing elements 1101, 1102, 1103 of a vertical focusing system 1104 in the form of cylindrical lenses arranged horizontally in the array. The beam that is nearly collimated with the horizontal line source LS2 passes through the focusing unit 1102 of the illumination unit to the observer plane OP as an example. According to Figure 4, many of the line sources LS1, LS2, LS3 are arranged one above the other. The light emitted by each light source is sufficiently coherent in the vertical direction and non-coherent in the horizontal direction. This light passes through the transmission element of the optical modulator SLM. This light is diffracted only in the vertical direction by the elements of the optical modulator SLM that encodes the hologram. The focusing element 1102 images the light source LS2 at the viewer plane OP with a number of diffraction stages (only one is useful). The light beam emitted by the light source LS2 is used as an example of the focusing element 1102 that passes only through the focusing system 1104. In Figure 4, the three beams present a first diffractive class 1105, a zeroth class 1106, and a negative one class 1107. A line source allows very high light intensity generation compared to a single point source. The use of multiple holographic regions that have increased efficiency and assigned a line source for each portion of the reconstructed three-dimensional scene enhances the effective light intensity. Another advantage of not using a laser is that a plurality of conventional light sources, such as those disposed behind a slot diaphragm that can be part of the shutter, can produce sufficient dimming. It includes an eye 1108.

Although a preferred method for holographic coding applicants (by using a virtual observer window) is described in WO 2004/044659 (US 2006/0055994), the entire disclosure of which is incorporated herein by reference. The means of reconstructing a three-dimensional scene, but it is necessary to clarify that the holographic display described here Rather than limiting the use of such methods, it encompasses all holographic display types known to be usable with magneto-optical spatial light modulators, as is known in the art.

B. Full-image display device with two magneto-optical spatial light modulators connected in series

This embodiment relates to a spatially modulated modulator (SLM) that provides complex modulation of light, i.e., independent modulation of amplitude and phase. In particular, this is about a spatial light modulator that is based on the use of the Faraday effect. This spatial light modulator can be used in a hologram display. This holographic display can be used on televisions, screens, laptops, mobile phones, personal digital assistants, digital walkmans, or any other device with a display.

This embodiment provides a holographic display device having two magneto-optical spatial light modulators in series, such a combination being capable of producing a three-dimensional image under appropriate illumination conditions. This display can be illuminated by multiple light sources or a single light source.

This embodiment relates to two magneto-optical spatial light modulators for modulation of light, wherein each magneto-optical spatial light modulator modulates amplitude, phase or a combination of amplitude and phase. In particular, each magneto-optical spatial light modulator uses a Faraday effect to modulate light. The two combined magneto-optical spatial light modulators can be used in a hologram display. Therefore, a complex number consisting of amplitude and phase can be compiled in transmitted light one by one.

A holographic display device comprising one or more light sources and two magneto-optical spatial light modulators in series can be used to sequentially modulate the amplitude and phase of the light and, if desired, in a compact manner. Examples of this embodiment include a first magneto-optical spatial light modulator and a second magneto-optical spatial light modulator. The first magneto-optical spatial light modulator modulates the amplitude of the transmitted light, and the second magneto-optical spatial light modulator modulates the phase of the transmitted light. Alternatively, the first magneto-optical spatial light modulator may modulate the phase of the transmitted light, and the second magneto-optical space The inter-optical modulator modulates the amplitude of the transmitted light. Alternatively, it may be a combination of amplitude and phase of each magneto-optical spatial light modulator such that the combination of two magneto-optical spatial light modulators can assist in full complexity modulation. Each magneto-optical spatial light modulator can be as described in Section A above. All assembly can be as described in Part A, except that two magneto-optical spatial light modulators are used here.

In the first step, the pattern for phase modulation is written in the first magneto-optical spatial light modulator. In the second step, the pattern for amplitude modulation is written in the second magneto-optical spatial light modulator. The light transmitted from the second magneto-optical spatial light modulator has been modulated in amplitude and phase. Therefore, when the observer observes the light emitted by the devices of the two magneto-optical spatial light modulators, A three-dimensional image was observed.

Due to the development of conventional techniques, phase and amplitude modulation techniques promote the performance of complex values. Thus, this embodiment can be applied to produce a holographic image so that the viewer can see the three-dimensional image.

Figure 2 depicts an example of this implementation. 20 is a lighting device for providing illumination of a planar area, wherein the illumination is sufficiently homogenous to enable generation of a three-dimensional image. An example for a large area image hologram is presented in US 2006/250671. A device like 20 may take the form of a white light source array, such as a cold cathode fluorescent lamp or a white light emitting diode that is incident on a focusing system, wherein the focusing system can be tight, Such as a lenticular array or a microlens array. Alternatively, the light source for 20 may be comprised of red, green, and blue lasers, or red, green, and blue light emitting diodes that emit sufficient coherent light. However, compared to laser sources, non-laser sources (eg, light-emitting diodes, organic light-emitting diodes, cold cathode fluorescent lamps) having sufficient spatial coherence are preferred. Laser sources have some drawbacks, such as causing laser spots on holographic reconstruction, relatively expensive, and possibly damaging the holographic display viewer or Safety issues such as the eyes of workers who assemble the omni-directional display device.

The element 20 may comprise one or two bismuth optical films for increasing the brightness of the display: such a film is known, for example, as described in US 5,056,892 and US 5,919,551.

The hologram generator 25 can be sized to range from a screen size (or smaller) that is applied to a mobile phone secondary screen to a one meter screen size for indoor large displays (or Bigger). Thus, the thickness of all of elements 20-23, 26-28 can range from one millimeter, or even less, up to tens of centimeters, or even more (e.g., in the case of large indoor displays). Element 21 is a polarizing element or a set of polarizing elements. An example of this is a linear polarizer. Another example is a reflective polarizer that transmits a linearly biased state and reflects an orthogonal linearly biased state - such a sheet is known, for example, as described in US 5,828,488. Another example is a reflective polarizer that transmits a circularly polarized state and reflects an orthogonal circularly biased state - such a sheet is known, for example, as described in US 6,181,395. Element 22 may be constructed of a color filter array such that pixels of colored light (e.g., red, green, and blue light) are directed toward element 23, although a color filter is not required if a colored light source is used. Element 23 is a magneto-optical spatial light modulator. In its simplest form, element 23 is an array of conductive material coils, each used to independently control the magnetic field in the display that experiences light traversing its corresponding pixel. Such control can be assisted by light passing through a medium having a significant Feld constant V such that linear polarization can achieve significant rotation a as it passes through the medium, as described in equation (1). This medium can be in the form of a doped fiberglass cylinder, or a similar shape, as described in US 2005/0201705. The medium can also be in the form of a magneto-optical film, as described in WO2005/122479A2, or as a magnetic photonic crystal.

Element 26 is a polarizing element or a set of polarizing elements. Element 27 is a magneto-optical spatial light modulator, such as described above with respect to element 23. Light exiting the magneto-optical spatial light modulator will then pass through a photo-biasing layer 28, such as a linear polarizer. With respect to transmitting light, element 23 is modulated in amplitude and element 27 is modulated in phase. It is also possible that component 27 modulates the amplitude and component 23 modulates the phase - in the case where the amplitude is at a maximum, it is desirable to be able to modulate the phase more accurately (i.e., with less noise), which is considered to be better. The magneto-optical spatial light modulators 23 and 27 are close to the pixel crosstalk problem which can reduce optical loss and light beam divergence: when the magneto-optical spatial light modulators 23 and 27 are very close, the magneto-optical space can be realized. A preferred approximation of the non-overlapping propagation of the colored light beam of the light modulator.

A viewer located at a distance 24 from the device including the compact hologram generator 25 can view the three-dimensional image from the direction of 25. Elements 20, 21, 22, 23, 26, 27, and 28 can be configured to be physically connected (realally connected), each forming a layer of structure such that the entirety is a single, unified object. Physical connections can be direct. Or indirect, if there is a thin intermediate layer, a film covering between adjacent layers is formed. Physical connections can be limited to small areas to ensure proper inter-arrangement, or can extend to larger areas, even the entire surface of the layer. The physical connection can be achieved by layer-to-layer bonding, for example by using an optical transfer adhesive to form a compact hologram generator 25, or by any other means (refer to the outline manufacturing procedure section). ). However, some or all of the elements 20, 21, 22, 23, 26, 27 and 28 may be separated if not particularly required.

Here we give a simple mathematical treatment of two series magneto-optical spatial light modulators for a spatially modulated optical modulator, for each pixel, a function of the current in the two coils. More precise processing is possible. For these calculations, the first Faraday rotator of the modulated phase, the first linear polarizer, and the second Faraday rotation of the modulated amplitude The second linear polarizer and the second linear polarizer are taken into consideration in this order.

The length of the first coil is L ₁ , the current is I ₁ , and the number of turns is N ₁ . The magnetic field generated along its own axis is thus H ₁ =N ₁ I ₁ /L ₁ . The second coil has a length L ₂ , a current of I ₂ , and a number of turns of N ₂ . The magnetic field generated along its own axis is thus H ₂ =N ₂ I ₂ /L ₂ . These equations are obtained from "Electromagnetic Fields and Waves" Second Edition by P. Lorrain and D. Corson (WH Freeman and Co, San Francisco, USA, 1970) at pages 315-318.

The input light has a circular polarization, and the complex amplitude of the circular polarization can be expressed according to the Jones algorithm (Jones calculus):

The Faraday effect at the first rotator shifts the phase of this circularly polarized component: α ₁ = V ₁ L ₁ H ₁ = V ₁ N ₁ I _{1 is} as described in equation (1). The amplitude after the Faraday rotator is The amplitude after the first linear polarizer is Regarding the calculation of the biased rotation by the second Faraday rotator, the linear polarization is decomposed into left and right circularly biased states, and the phases are shifted by α ₂ and -α ₂ , respectively, where α ₂ = V ₂ L ₂ H ₂ = V ₂ N ₂ I ₂ after the amplitude of the second Faraday rotator is Finally, the amplitude after the second linear polarizer is Two magneto-optical spatial light modulators modulate the amplitude | cos(α ₂ )| with phase α ₁ .

Therefore, the coil currents I ₁ and I ₂ can be used to control each pixel phase α ₁ and the amplitude factor | cos(α ₂ )| because these quantities are equal to V ₁ N ₁ I ₁ and | cos(V ₂ N ₂ I, respectively). ₂ )|.

Now, we give specific examples of implementation. The two magneto-optical spatial light modulators are combined in series. Each layer contains modulated pixels that are controlled by the coil and are independently addressed. The layers are arranged so that the light modulated in the first layer of pixels is then modulated by the corresponding pixels of the second layer. The modulation characteristics of each layer are such that two layers in series can help the complex modulation of light, ie amplitude and phase. This spatial light modulator can include an array of controllable 稜鏡 elements to aid beam steering, but this is not necessary. This spatial light modulator can include an integrated computer, but this is not necessary.

Figure 5 shows a cross-sectional view where this spatial light modulator contains:

. Two layers of magneto-optical spatial light modulators 53, 54, 56, 57

.稜鏡 element 59 for beam steering

. A computer integrated in a spatial light modulator that provides hologram calculation and control of modulators and components. This can be referred to as a computer in a display (CIAD) 52. The circuit for such a computer can be developed on a glass substrate, as described in the applicant's patent application No. GB 0709376.8 and GB 0709379.2. Three pixels are shown in Figure 5. The real device should have more pixels. For example, a real device can have a 1000x1000 pixel array, which contains millions of pixels.

The device shown in Figure 5 includes three pixels 511, 512 and 513 and a weir element 59. Of course, the implementation is not limited to these numbers and ratios of 3:1.

The spatial light modulator shown in Figure 5 contains several layers with

. Bottom glass substrate 51

. Computer in the display 52

. The first layer 53 with coils, here showing a cross-sectional view of three coils

. First magnetic photonic crystal layer 54

. First polarizer 55

. Second magnetic photonic crystal layer 56

. a second layer 57 having a coil, here showing a cross-sectional view of three coils

. Second polarizer 58

.稜鏡 element 59 for beam steering

. Top glass substrate 510

Three pixels 511, 512, and 513 are shown in FIG. Each pixel stack extends from the first layer 53 of the coil to the second polarizer 58, as indicated by the dashed lines. A spatial light modulator for pixel 511 will be described. The direction of light propagation is from the bottom glass substrate 51 to the top glass substrate 510.

In the first magnetic photonic crystal layer (MPC) 54, the coil 514 generates a magnetic field and controls the modulation of the light. Light is modulated by a first polarizer 55 followed by a second magnetic photonic crystal layer 56 controlled by a second coil 516. The second polarizer 58 is at The output position of the pixel 511. Each of the magnetic photonic crystal layers is composed of a multilayer structure of a magneto-optical layer, which can greatly increase the Feld constant. Some of the multilayer structures for magnetic photonic crystal layers are described in "A Presentation for Investors" by Panorama Labs of Rockefeller Center, 1230 Avenue of the Americas, 7th Floor, New York, NY 10020 USA (www.panoramalabs.com). Obtained from the Internet.

The two magnetic photonic crystal layers 54, 56 are used to modulate the phase and amplitude of light passing through each pixel. For example, the light entering the pixel 511 is a circularly polarized state on the left side. The light is still circularly polarized to the left after passing through the magnetic photonic crystal layer 54, and has a phase shift φ1 associated with the magnetic field generated by the coil 514. The polarization sheet 55 converts the left circular polarization into a linear polarization with a constant amplitude and a phase shift φ1. This light is then modulated in the magnetic photonic crystal layer 56. Thereafter, the biasing is still linear, but the direction of the polarization will rotate the alpha angle, which is related to the magnetic field generated by the coil 516. After the second linear polarizer 58, the light will have a fixed polarization direction and an amplitude associated with the rotation angle a.

The above is an example of how to use two magnetic photonic crystals to modulate the phase and amplitude of light in a pixel. Of course, other modulation characteristics, input and output biasing, and combination of biasing sheet orientations are possible, as can be observed in conventional techniques. In each of the magnetic photonic crystals, there may be a mixed modulation of amplitude and phase. For fully complex modulation, in combination the combined modulation in the magnetic photonic crystal 54 and the magnetic photonic crystal 56 will help the amplitude from zero to the maximum amplitude value control the complex modulation and the phase controllable complexity from 0 to 2π radians change.

The optical layer with germanium element 59 comprises electrodes 517, 518 and a cavity filled with two separate liquids 519, 520. Each liquid fills the prismatic portion of the cavity. As an example, the liquid can be oil or water. The slope of the interface between the liquids 519, 520 is It is determined by the voltage applied to the electrodes 517, 518. If the liquids have different refractive indices, the beams will be biased, the bias being determined by the voltage applied to the electrodes 517, 518. Thus, the jaw element 59 acts like a controllable beam steering element. This is an important feature for the applicant's method to be applied to electronic holographic techniques that require tracking of the virtual observer window to the viewer's eyes. Patent application Nos. DE 102007024237.0 and DE 102007024236.2, filed by the applicant, describe the tracking of the virtual observer window to the observer's eye with a sputum element.

The computer 52 in the non-essential display is used to calculate the current in the coil of the hologram and control pixels, and to control the 稜鏡 element. A computer implementation in a display for holographic display is described in the patent application nos. GB 0709376.8 and GB 0709379.2.

In Figure 5, the computer 52 in the display is directly connected to the bottom glass substrate and is fabricated using thin film transistor technology. The control signals for the coil and turns elements are converted via feedthroughs or conductive contacts as shown by symbol 515 in FIG. This is an example. Computers in displays in other locations are also possible, for example:

. The computers in the two displays, one at the bottom and the other at the top substrate, can be synchronized via feedthroughs or via external synchronization of the computers in the two displays.

. The computers in the two displays are located on each side of the polarizer 55. This ensures that the distance to the coil is very short.

. The computer in one or two displays is located on one or both sides of an elastic sheet which is mounted on a glass substrate, a magnetic photonic crystal, a coil or a polarizer. Of course, the implementation is not the location of the computer in the display listed here.

There are several possibilities for the feedthrough or the junction between the computer in the display, the electrodes of the coil and the 稜鏡 element, or the computer in several displays, for example:

. Etching or drilling of holes, or holes and lithographic printing filled with conductive materials.

. Adhesion of the contact area of one layer to the contact area of another layer with conductive adhesive

. A composite multilayer sheet can be made that can contain a computer, polarizer or coil in one or several displays. Of course, the way of doing things is not the possibility listed here.

Care must be taken to avoid or compensate for crosstalk between the magnetic fields.

. Crosstalk that causes optical modulation errors between the magnetic fields of the first coil 514 and the second coil 516 (stray magnetic field) can be calculated and compensated. Calculations and compensation can be performed on-the-fly or using a look-up table.

. Crosstalk between adjacent pixels is typically negligible because the stray magnetic field exiting the coil axis is small. Otherwise, crosstalk can be calculated or compensated using instant or look-up tables.

. The crosstalk of the stray magnetic field from the computer to the magnetic photonic crystal in the display (and vice versa) can be minimized through careful wiring design. For example, circuit paths with the same but opposite direction currents can be placed together such that the far field magnetic field is offset to a good approximation.

Crosstalk of light from one pixel to adjacent pixels can be avoided by a short optical path from 53 to 58 within the pixel (i.e., in Figure 5, in a direction perpendicular to 51 and toward 510). This reduces the amount of diffracted light to adjacent pixels to a negligible value.

The polarizers 55, 58 should also be thin layers. Examples include:

. Polymer sheet polarizer (Polymer sheet polarizer)

. A layer with intrusive small metal particles that absorbs a direction of polarization.

. A metal wire grid polarizer consisting of an array of parallel nanowires that transmits a polarization direction of light and reflects another polarization direction (eg, by Moxtek Inc. of 452 West 1260 North, Orem, UT 84057 , products produced by USA).

The entire spatial light modulator can be a small spatial light modulator with a screen size of a few centimeters, such as a secondary screen for a mobile phone, or a screen size of one centimeter or less, such as space used in a projection display. A light modulator in which a spatial light modulator is optically magnified. Alternatively, it can be a large spatial light modulator having a screen size of up to one meter or even larger (in a direct view display where multiple viewers can see the actual size of the spatial light modulator). Space light modulators with screen sizes between large and small are also possible for a variety of different applications.

The spatial light modulator described in the above example has the following characteristics

. Two magnetic photonic crystals for independent modulation of amplitude and phase

.稜鏡 element for beam steering

. A computer in the display for hologram calculation and control of coil and cymbal components.

It is also possible to create a less complex spatial light modulator:

. Space light modulators without 稜鏡 components can be used in conjunction with external beam steering elements, such as light source tracking, scanning mirrors or external 稜鏡 components.

. A spatial light modulator that does not have a computer in the display can be used in conjunction with an external computer for hologram calculation and coil and 稜鏡 component control.

. A spatial light modulator without eye tracking can be used in a handheld device in which the user manually rotates the device to position the virtual viewer window in his eye position.

The disclosed spatial light modulator is more suitable for use in holographic display, which is a projection holographic display or a direct-view holographic display. Spatial light modulators with integrated germanium elements for beam steering are more suitable for use in holographic displays, and are based on Applicant's method for holographic display using virtual observer window tracking.

However, for holographic coding, the applicant's method of using a virtual observer window is described in the content of WO 2004/044659 (US 2006/0055994), for example, by the applicant, in which a With the method of dimming the diffracting method for reconstructing the three-dimensional scene, it is necessary to know that the holographic display of this embodiment is not limited to such a method, but includes all known holographic display types, and can be combined with a pair of magneto-optical spatial light. Modulators are used in combination to produce complex holographic encoding as seen in conventional techniques.

C. Close combination of magneto-optical spatial light modulator and compact light source

This embodiment provides a close combination of a magneto-optical spatial light modulator and a coherent compact light source that produces a three-dimensional image with proper illumination.

In this embodiment, a close combination of a magneto-optical spatial light modulator that does not require imaging optics and a compact source is described. This embodiment provides a close combination of a light source or multiple sources, a focusing tool, a magneto-optical spatial light modulator, and an optional beam splitter element that produces a three-dimensional image with appropriate illumination. Since "no imaging optics is required", this means that there is no focusing tool, except for the method for focusing the light source or source, for example, such a method is typically a microlens array.

Figure 11 depicts an example of an implementation. 110 is a lighting device for providing illumination of a planar area, wherein the illumination is sufficiently homogenous to enable generation of three Dimensional image. An example of a lighting device for a large area image hologram is presented in US 2006/250671, and an example is shown in FIG. A device such as 110 may take the form of a white light source array, such as a cold cathode fluorescent lamp or emit light as a white light emitting diode incident on a focusing system, wherein the focusing system may be compact, such as a lenticular array or micro. Lens array. Alternatively, the light source for 110 may be comprised of red, green, and blue lasers, or red, green, and blue light emitting diodes that emit sufficient coherent light. The red, green, and blue light emitting diodes can be organic light emitting diodes (OLEDs). However, compared to laser sources, non-laser sources (eg, light-emitting diodes, organic light-emitting diodes, cold cathode fluorescent lamps) having sufficient spatial coherence are preferred. Laser sources have some disadvantages, such as laser speckles on holographic reconstruction, relatively expensive, and may damage the eyes of a holographic display viewer or a holographic display assembly. Security issue.

The element 110 may comprise one or two bismuth optical films for increasing the brightness of the display: such a film is known, for example, as described in US 5,056,892 and US 5,919,551.

Element 110 may have a thickness of about a few centimeters or less. In the preferred embodiment, the elements 110-113, 116 may all be less than 3 cm thick to provide a closely spaced, compact source. Element 111 may be constructed of a color filter array such that pixels of colored light (e.g., red, green, and blue light) are directed toward element 112, although a color filter is not required if a colored light source is used. Element 112 is a biasing element or a set of biasing elements. Element 113 is a magneto-optical spatial light modulator. Element 116 is a biasing element or a set of biasing elements. Element 116 can be followed by an optical beam splitter element. A viewer located at point 114 some distance from the device containing the compact hologram generator 115 can view the three-dimensional image from the direction of 115.

The optical constituents described in Section A can be included in the compact hologram generator 115 as can be seen in the prior art.

A magneto-optical spatial light modulator is a type of spatial light modulator in which each element in the array of elements can be addressed electronically to modulate the biased state of the polarized light using the Faraday effect. Each element performs some effect on the incident light, such as modulating the amplitude of the light it transmits, or modulating the phase of the light it transmits, or modulating the combination of the amplitude and phase of the light it transmits. An example of a magneto-optical spatial light modulator is provided in WO2005/076714A2, and other spatial light modulators of this type are also known.

Elements 110, 111, 112, 113, and 116 can be configured to be physically connected (realally connected), each forming a layer of structure such that the entirety is a single, unified object. Physical connections can be direct. Or indirect, if there is a thin intermediate layer, a film covering between adjacent layers is formed. Physical connections can be limited to small areas to ensure proper inter-arrangement, or can extend to larger areas, even the entire surface of the layer. The physical connection can be achieved by layer-to-layer bonding, for example by using an optical transfer adhesive to form a compact hologram generator 115, or by any other means (refer to the outline manufacturing procedure section). ).

Figure 4 is a side view of a conventional technique showing three focusing elements 1101, 1102, 1103 of a vertical focusing system 1104 in the form of cylindrical lenses arranged horizontally in the array. The beam that is nearly collimated with the horizontal line source LS2 passes through the focusing unit 1102 of the illumination unit to the observer plane OP as an example. According to Figure 4, many of the line sources LS1, LS2, LS3 are arranged one above the other. The light emitted by each light source is sufficiently coherent in the vertical direction and non-coherent in the horizontal direction. This light passes through the transmission element of the optical modulator SLM. This light is diffracted only in the vertical direction by the elements of the optical modulator SLM that encodes the hologram. Focusing element 1102 is flat at the viewer The face OP is an imaging source LS2 with a number of diffraction stages (only one is useful). The light beam emitted by the light source LS2 is used as an example of the focusing element 1102 that passes only through the focusing system 1104. In Figure 4, the three beams present a first diffractive class 1105, a zeroth class 1106, and a negative one class 1107. A line source allows very high light intensity generation compared to a single point source. The use of multiple holographic regions that have increased efficiency and assigned a line source for each portion of the reconstructed three-dimensional scene enhances the effective light intensity. Another advantage of not using a laser is that a plurality of conventional light sources, such as those disposed behind a slot aperture that can be part of the shutter, can produce sufficient dimming.

In general, the hologram display is used to reconstruct the wavefront in the virtual observer window. A wavefront is something that an actual object will produce if it exists. When the observer's eye is in the virtual observer window, he will see the reconstructed object, where the virtual observer window may be a virtual observer window in multiple virtual observer windows (VOWs). As shown in FIG. 6A, the hologram display is composed of the following constituent elements: a light source 601, a lens 602, a spatial light modulator SLM, an unnecessary beam splitter 603, and an observer window 604.

In order to facilitate the close combination of the spatial light modulator and the compact light source that can display the holographic image, the single light source and the single lens in FIG. 6A can be replaced by the light source array 605 and the lens array 606 or the lenticular array, respectively. Shown in six B. In Figure 6B, the light source illuminates the spatial light modulator and the lens images the light source to the viewer plane. The spatial light modulator encodes the holographic image and modulates the incoming wavefront so that the wavefront of the demand can be reconstructed in the virtual observer window. An optional beam splitter element can be used to create a number of virtual observer windows, such as a virtual viewer window for the left eye and a virtual observer window for the right eye.

Assuming that the source array and the lens array or the lenticular array are used, the light source in the array must be set so that all lenses pass through the lens array or the lenticular array. The light will go to the virtual observer window at the same time.

The device of Figure 6B is suitable for a compact design that can be applied to a compact hologram display. Such a holographic display can be applied to mobile applications, such as in a mobile phone or a personal digital assistant. Typically, such a hologram display will have a screen size of one inch or several inches. Suitable constituent elements will be described in detail below.

1) Light source / light source array

In a simple case, a fixed single source can be used. If the observer moves, the viewer can be tracked and the display adjusted so that the viewer at the new location can observe the resulting image. At this time, if there is no tracking of the virtual observer window, the tracking is performed by the beam steering element after the spatial light modulator.

The configurable array of light sources can be implemented by another magneto-optical spatial light modulator that is illuminated by the backlight. In order to generate an array of point or line sources, only the appropriate pixels will switch to the transfer state. The maximum switching speed of this type of array will be much faster than the switching speed in other spatial light modulators, such as spatial light modulators using liquid crystal or micro-motor system technology. The aperture of these sources must be small enough to ensure full spatial coherence to the holographic reconstruction of the target. An array of point sources can be used with a two-dimensional array of lenses. An array of line sources is preferably used with a lenticular array of cylindrical lenses arranged in parallel.

It is preferred to use an organic light emitting diode display as the light source array. When an organic light emitting diode display is used as the light source array, only the pixels on which switching is made must be used to create a virtual viewer window at the position of the eye. The organic light emitting diode display may have a two-dimensional array of pixels or a one-dimensional array of line sources. The illuminating area of each point source or the width of each line source must be sufficiently small to ensure that full spatial coherence is provided to the holographic reconstruction of the target. Similarly, the array of point sources Columns are more suitable for use with a two-dimensional array of lens arrays. An array of line sources is preferably used with a lenticular array of cylindrical lenses arranged in parallel.

2) Focusing tool: single lens, lens array or lenticular array

The focusing tool images a light source or multiple sources to the viewer plane. When the spatial light modulator is very close to the focusing tool, the Fourier transform of the information encoded in the spatial light modulator will be in the observer plane. The focusing tool contains one or several focusing elements. The position of the spatial light modulator and the focusing tool is interchangeable.

For the close combination of a magneto-optical spatial light modulator and a well-consistent compact light source, a thin focusing tool is necessary: conventionally used refractive lenses are too thick. Instead, a diffractive or holographic lens is used. This diffractive or holographic lens can have the function of a single lens, a lens array or a lenticular array. Such materials are present, such as surface relief holographic products provided by Physical Optics Corporation, Torrance, CA, USA. Alternatively, a lens array can be used. The lens array comprises two-dimensionally arranged lenses, and each lens is a light source that is assigned to an array of light sources. Another option is to use a lenticular array. The lenticular array comprises a one-dimensional array of cylindrical lenses, and each lens has a corresponding light source in the array of light sources. As described above, if a light source array and a lens array or a lenticular array are used, the light sources in the array must be arranged such that the light energy of all the lenses passing through the lens array or the lenticular array simultaneously reaches the virtual viewer window.

Light passing through a lens array or a lens of a lenticular array is non-coherent to any other lens. Therefore, the hologram image encoded on the spatial light modulator is composed of a sub-hologram, and each sub-image corresponds to one lens. The aperture of each lens must be large enough to ensure adequate resolution of the reconstructed object. It is also possible to use a lens whose aperture is almost as large as the typical size of the hologram coding region, as in It is described in US2006/0055994. That is to say, the aperture of each lens should be of the order of one or several millimeters.

3) Spatial light modulator

The hologram is encoded on the spatial light modulator. Typically, the encoding of an hologram is composed of a two-dimensional complex array. Therefore, ideally the spatial light modulator should be able to modulate the amplitude and phase of the local beam passing through each pixel of the spatial light modulator. However, a typical spatial light modulator can only modulate amplitude or phase, and cannot independently modulate amplitude and phase.

Amplitude modulated spatial light modulators can be used in combination with track phase encoding, such as Burckhardt encoding. Its disadvantage is that it requires three pixels to encode a complex number, and the brightness of the reconstructed object will be lower.

The phase modulation spatial light modulator produces a higher brightness reconstruction. For example, so-called 2-phase encoding can be used, using two pixels to encode a complex number.

Although magneto-optical spatial light modulators have significant edge characteristics that create undesirable higher diffraction levels in their diffraction patterns, this problem can be improved or avoided by using soft apertures. The soft aperture is an aperture that does not have a sharp transmission cut off. An example of a soft aperture transmission method is to have a Gaussian profile. Gaussian graphics are known to be helpful for diffraction systems. The reason is that the Fourier transform of the Gaussian function is the mathematical result of the Gaussian function itself. Therefore, the diffraction does not change the beam intensity waveform function except for the lateral scale parameter, as compared to the aperture with a sharp cutoff in the transfer pattern itself. An array of sheets of Gaussian transfer patterns can be provided. When these are provided and aligned with the aperture of the magneto-optical spatial light modulator, there will be no higher diffraction stages or a higher reduction of higher windings than systems with sharp cut-offs in the beam delivery pattern. The system of the class.

4) Beam splitter component

The virtual observer window is limited to a periodic interval of the Fourier transform of the information encoded by the spatial light modulator. Using the existing maximum resolution spatial light modulator, the virtual observer window is 10 millimeters in size. In some cases, this may be too small for an application to be in a holographic display without tracking. One solution to this problem is to exploit the spatial multiplexing of multiple virtual observer windows: creating multiple virtual observer windows. In the case of spatial multiplexing, the virtual observer window is generated simultaneously at different locations on the spatial light modulator. This can be achieved by a beam splitter. For example, one set of pixels on the spatial light modulator is encoded using the information of the virtual observer window 1 and the other set of pixels is encoded using the information of the virtual observer window 2. The beam splitter will distinguish the two sets of light so that the virtual observer window 1 and the virtual observer window 2 are juxtaposed in the observer plane. A larger virtual viewer window can be created using the seamlessly configuring virtual viewer window 1 and virtual viewer window 2. Multiplexing can also be used to create virtual observer windows for the left and right eyes. In such cases, no seam juxtaposition is required, and there may be a gap between one or several virtual viewer windows for the left eye and one or several virtual observer windows for the right eye. Care must be taken not to overlap the higher diffraction level of the virtual observer window with other virtual observer windows.

A simple example of a beam splitter element is a parallax barrier consisting of black stripes with a transparent area between the black stripes, as described in US 2004/223049. Another example is a lenticular sheet, as described in US 2004/223049. Other examples of beam splitter elements are lens arrays and germanium masks. In a tight hologram display, it may typically be desirable to have There is a beam splitter element because a typical 10 mm sized virtual observer window is only enough to provide one eye, which is not consistent with a typical viewer having two eyes and is about 10 cm apart. However, time multiplexing can be used as an alternative to spatial multiplexing. Time multiplexing can be achieved by using a magneto-optical spatial light modulator because the magneto-optical spatial light modulator has very fast switching capabilities, as described above. In the absence of space multiplex, it will not be necessary to use the beam splitter element.

Spatial multiplexing can also be used in the generation of color hologram reconstruction. For spatial color multiplex, pixels are grouped for red, green, and blue color elements. These groups are spatially separated on the spatial light modulator and simultaneously illuminate red, green and blue light. Each group will be encoded using a hologram calculated for the corresponding color element of the target. Each group will reconstruct its color elements in the hologram reconstruction.

5) Time multiplexing

In the case of time multiplex, the virtual observer windows are successively generated at the same position on the spatial light modulator. This can be achieved by alternating the position of the light source with the synchronous re-encoding spatial light modulator. The alternation of the position of the light sources must be such that the virtual observer windows in the viewer plane are seamlessly juxtaposed. If the time multiplex is fast enough, that is, the full period is greater than 25 Hz, the eye will see a continuously expanding virtual observer window.

Multiplex can also be used to create virtual observer windows for the left and right eyes. In such cases, no seam juxtaposition is required, and there may be a gap between one or several virtual viewer windows for the left eye and one or several virtual viewer windows for the right eye. Such multiplexing can be space or time multiplex.

Space and time multiplexing can also be combined. As an example, three virtual observer windows are spatially multiplexed to create an expanded virtual observer window for one eye. This expanded virtual observer window is time multiplexed to produce The expanded virtual observer window for the left eye and the expanded virtual observer window for the right eye.

Care must be taken not to overlap the higher diffraction level of one virtual observer window with another virtual observer window.

The multiplexing of the expanded virtual observer window is more recommended than the re-encoding of the spatial light modulator, because for observer movement, it provides an expanded virtual observer window with continuous parallax changes. In simple terms, multiple unions that are not re-encoded provide repetitive content in different parts of the expanded virtual observer window.

Time multiplexing can also be used in the generation of color hologram reconstruction. For time multiplexing, the hologram of the three color elements is encoded sequentially on the spatial light modulator. These three sources are switched synchronously with the re-encoding on the spatial light modulator. If the repetition of the full cycle is fast enough, ie greater than 25 Hz, the eye will see a continuous color reconstruction.

Time multiplexing can be achieved by using a magneto-optical spatial light modulator because the magneto-optical spatial light modulator has very fast switching capabilities, as described above.

6) Eye tracking

In a close combination of a magneto-optical spatial light modulator with eye tracking and a well-constrained compact light source, the eye position detector can detect the observer's eye position. Therefore, one or several virtual observer windows can be automatically positioned at the eye so that the viewer can see the reconstructed object through the virtual observer window.

However, tracking is not always practiced because of additional device requirements and power demand constraints for performance, especially for portable devices. If there is no tracking, the observer must adjust the displayed position. This is easily achievable because in the preferred embodiment, the compact display is a handheld display that can be included in a personal digital assistant or mobile phone. Use of personal digital assistants or mobile phones The display is usually viewed vertically, and it is not too difficult to adjust the virtual viewer window to correspond to the position of the user's eyes. It is well known that users of handheld devices tend to adjust the orientation of the device in their hand to obtain the most desirable viewing state, as described in WO 01/96941. Therefore, in such a device, the function of the user's eye tracking is not required as well as the tracking optics that are not as compact as the scanning mirror. However, eye tracking can be applied to other devices, and for these devices, additional equipment and power requirements do not create an excessive burden.

In the absence of tracking, in order to simplify the adjustment of the display, the close combination of the magneto-optical spatial light modulator and the fully coherent compact light source requires a sufficiently large virtual observer window. A better virtual observer window size should be several times the size of the pupil of the eye. This can be done by using a single large virtual observer window created by a small pitch spatial light modulator or by a number of smaller virtual observer windows generated using a large pitch spatial light modulator.

The position of the virtual observer window is determined by the position of the light source in the array of light sources. The eye position detector detects the position of the eye and sets the position of the light source so that the virtual observer window fits the position of the eye. This type of tracking is described in US 2006/055994 and US 2006/250671.

Alternatively, the virtual viewer window can be moved when the light source is in a fixed position. The light source tracks a spatial light modulator that is relatively insensitive to changes in the angle of incidence of the light of the light source. If the light source is moved to move the virtual observer window position, such settings may be difficult to achieve through the close combination of the compact light source and the spatial light modulator due to the possibility of abnormal light propagation in tight combinations. In such cases, it would be helpful to have a fixed optical path in the display and a beam steering element that is the last optical component in the display.

7) Example

An example of a close combination of a magneto-optical spatial light modulator and a coherent compact light source will now be described. Such a combination can produce a three-dimensional image with appropriate illumination and can be incorporated into a personal digital assistant or mobile phone. . The close combination of the magneto-optical spatial light modulator and the fully coherent compact light source includes an organic light emitting diode display, a magneto-optical spatial light modulator and a lens array as an array of light sources, as shown in FIG. In Figure 12, the virtual observer window is labeled OW.

Depending on the desired location of the virtual viewer window, a particular pixel is activated in the organic light emitting diode display. These pixels illuminate the magneto-optical spatial light modulator MOSLM and are imaged by the lens array 1201 to the viewer plane OW. In an organic light emitting diode display OLED, at least one pixel of each lens of the lens array is activated. In drawing a given size, if the pixel pitch is 20 μm (12d1), a virtual observer window with a lateral increment of 400 μm (12d2) can be tracked. Such tracking is quasi-continuous.

The organic light emitting diode pixel is a light source having only partial spatial homology. Partial homology will produce a fuzzy reconstruction of the target point. In drawing a given size, if the pixel width is 20 μm, a reconstruction with a lateral blur of 100 μm is generated at a target point of 100 mm from the display. This is sufficient for the resolution of the human visual system.

Light passing through different lenses in the lens array does not have significant mutual homology. The need for coherence is limited to each single lens in the lens array. Therefore, the resolution of the reconstruction target point is determined by the pitch of the lens array. Therefore, for the human visual system, the typical lens pitch will be 1 mm to ensure sufficient resolution. If the pitch of the organic light-emitting diodes is 20 μm, this means that the ratio of the lens pitch to the organic light-emitting diode pitch is 50:1. If each lens has only one When an organic light-emitting diode is irradiated, this means that of every 50^2 = 2,500 organic light-emitting diodes, only one organic light-emitting diode will be irradiated. Therefore, this display will be a low power display. The difference between the holographic display of the embodiment and the conventional organic light-emitting diode display is that the former concentrates on the viewer's eyes, whereas the latter emits light to 2π steradian. Conventional organic light-emitting diode displays can achieve luminosity of about 1,000 cd/m^2 (calculated by the inventors in this embodiment), and in practical applications, the illuminating organic light-emitting diode should be able to reach 1,000 cd. /m^2 Several times the luminosity.

The virtual observer window is a diffractive class that limits the Fourier spectrum of the information encoded in the spatial light modulator. If the pixel spacing of the magneto-optical spatial light modulator is 20 μm, the virtual viewer window will have a width of 10 mm at a wavelength of 500 nm. The virtual observer window can utilize space or time multiplexing to piece together several virtual observer windows into an expanded virtual observer window. In the case of spatial multiplexing, additional optical components such as beam splitters are required.

Color hologram reconstruction can be achieved by time multiplexing. The red, green, and blue pixels of the color organic light-emitting diode display are sequentially activated by synchronous re-encoding of the spatial light modulator, which has calculations for red, green, and blue optical wavelengths. Full picture.

The display can include an eye position detector to detect the position of the observer's eyes. The eye position detector is connected to a control unit that is used to control the activation of the pixels of the organic light emitting diode display.

The calculation of the hologram image encoded on the spatial light modulator is preferably performed by an external coding unit because it requires a higher computational power. The display data is then transmitted to a personal digital assistant or mobile phone to display a three-dimensional image of the hologram.

D. Close combination of a pair of magneto-optical spatial light modulators

In another embodiment, a combination of two magneto-optical spatial light modulators can be used and the amplitude and phase of the light can be sequentially modulated in a compact manner. Therefore, the complex number composed of the amplitude and the phase can be encoded in the transmitted light one by one.

This embodiment includes a close combination of two magneto-optical spatial light modulators. The first magneto-optical spatial light modulator modulates the amplitude of the transmitted light, and the second magneto-optical spatial light modulator modulates the phase of the transmitted light. Alternatively, the first magneto-optical spatial light modulator may modulate the phase of the transmitted light, and the second magneto-optical spatial light modulator modulates the amplitude of the transmitted light - when the amplitude is at a maximum, it is desirable to more accurately modulate the phase The bit situation (ie has less noise) is considered better. Each magneto-optical spatial light modulator can be as described in Section C. In addition to using two magneto-optical spatial light modulators, the overall configuration can be as described in Section C. Any combination of other kinds of magneto-optical spatial modulator modulation characteristics that are equivalent to independent modulation of amplitude and phase is possible.

In a first step, the first magneto-optical spatial light modulator is encoded using a pattern for amplitude modulation. In a second step, the second magneto-optical spatial light modulator is encoded using a pattern for phase modulation. The light transmitted from the second magneto-optical spatial light modulator has been modulated in amplitude and phase. Therefore, when the observer observes the light emitted by the devices of the two magneto-optical spatial light modulators, A three-dimensional image was observed.

Due to the development of conventional techniques, phase and amplitude modulation techniques promote the performance of complex values. In addition to this, magneto-optical spatial light modulators can have high resolution. Thus, this embodiment can be applied to produce a holographic image so that the viewer can see the three-dimensional image.

Figure 13 depicts an example of an implementation. 130 is a lighting device for providing illumination of a planar area, wherein the illumination is sufficiently homogenous to enable generation of a three-dimensional image. An example for a large-area image hologram is presented in US 2006/250671, and an example is shown in Figure 4. Like the 130 device can be white The form of the array of light sources, such as a cold cathode fluorescent lamp or emitted light, is a white light emitting diode incident on the focusing system, wherein the focusing system can be compact, such as a lenticular array or a microlens array. Alternatively, the light source for 130 may be comprised of red, green, and blue lasers, or may be comprised of red, green, and blue light emitting diodes that emit sufficient tonal light. The red, green, and blue light emitting diodes can be organic light emitting diodes (OLEDs). However, compared to laser sources, non-laser sources (eg, light-emitting diodes, organic light-emitting diodes, cold cathode fluorescent lamps) having sufficient spatial coherence are preferred. Laser light sources have some disadvantages, such as laser spots that can cause laser spots on holographic reconstruction, are relatively expensive, and can damage the omnidirectional display of the viewer or the eyes of the omni-directional display device.

Element 130 can have a thickness of about a few centimeters or less. In the preferred embodiment, elements 130-135 may all be less than 3 cm thick to provide a closely spaced, compact source. Element 131 may be constructed of a color filter array such that pixels of colored light (e.g., red, green, and blue light) are directed toward element 132, although a color filter is not required if a colored light source is used. Element 132 is a biasing element or a set of biasing elements. Element 133 is a magneto-optical spatial light modulator. Element 134 is a magneto-optical spatial light modulator. Each of elements 133 and 134 includes a biasing element or a set of biasing elements. Element 135 is an unnecessary beam splitter element. For transmitting light, element 133 is modulated in amplitude and element 134 is modulated in phase. Alternatively, the amplitude is modulated by element 134 and the phase of element 133 is modulated. The magneto-optical spatial light modulators 134 and 133 are close to the problem of reducing pixel loss and pixel crosstalk caused by beam divergence: when the magneto-optical spatial light modulators 134 and 133 are in close proximity, the magneto-optical space can be realized. A preferred approximation of the non-overlapping propagation of the colored light beam of the light modulator. A viewer located at point 137 some distance from the device including the compact hologram generator 136 can view the three-dimensional image from the direction of 136.

Elements 130, 131, 132, 133, 134, and 135 are configured to be physically connected (realally connected), each forming a layer of structure such that the entirety is a single, unified object. Physical connections can be direct. Or indirect, if there is a thin intermediate layer, a film covering between adjacent layers is formed. Physical connections can be limited to small areas to ensure proper inter-arrangement, or can extend to larger areas, even the entire surface of the layer. The physical connection can be achieved by layer-to-layer bonding, for example by using an optical transfer adhesive to form a compact hologram generator 136, or by any other means (refer to the outline manufacturing procedure section). ).

Where the magneto-optical spatial light modulator performs amplitude modulation, in a typical setup, the incident optical beam will be linearly biased by passing the beam through a linear polarizer. The amplitude modulation is controlled by the rotation of the linearly biased state in the magnetic field applied along the direction of propagation of the light, and the applied magnetic field is a state of polarization that affects the light by the Faraday effect. In such a device, the light exiting the magneto-optical spatial light modulator passes through another linear polarizer, allowing any rotation of the polarization state of the light to cause the intensity to be weakened, as it passes through the magneto-optical spatial light modulator. Same time.

Where the magneto-optical spatial light modulator performs phase modulation, in a typical setup, the incident read optical beam will be linearly polarized by passing the beam through a linear polarizer and a quarter wave plate. Phase modulation is controlled by a magnetic field applied along the direction of light propagation that affects the phase state of the light through the Faraday effect. The applied magnetic field is generated by the current flowing through the coil. In phase modulation, for each pixel, the output beam and the input beam will have a phase difference and be a function of the current flowing through the coil corresponding to each pixel.

A compact combination for compact holographic display that includes two magneto-optical spatial light modulators combined in a small or minimal separation. In a preferred embodiment, the two spatial light modulators have the same number of pixels. Because of the two magneto-optical spatial tones The transformer is not equidistant to the observer, so the pixel spacing of the two magneto-optical spatial light modulators may need to be slightly different to compensate for the effects of different distances on the viewer. The light that has passed through the pixels of the first spatial light modulator passes through the pixels corresponding to the second spatial light modulator. Therefore, the two spatial light modulators modulate the light, and the complex modulation of amplitude and phase can be achieved independently. As an example, the first spatial light modulator is amplitude modulated and the second spatial light modulator is phase modulated. Similarly, any combination of modulation characteristics of the other two spatial light modulators that are equivalent to independent modulation of amplitude and phase is possible.

Care must be taken that the light passing through the pixels of the first spatial light modulator can only pass through the pixels corresponding to the second spatial light modulator. If the light passing through the pixels of the first spatial light modulator passes through the second spatial light modulator adjacent to the non-corresponding pixels, a crosstalk phenomenon will occur. This crosstalk may result in reduced image quality. Four possible ways to minimize crosstalk between pixels are provided here. It will be apparent from the conventional techniques that these methods are equally applicable to the embodiment of Part B.

(1) The first and simplest method is to directly connect or bond together two spatial light modulators after the aligned pixels have been adjusted. There will be a diffraction phenomenon on the pixels of the first spatial light modulator, causing the light to deviate from propagation. The separation between the spatial light modulators must be such that the crosstalk between adjacent pixels of the second spatial light modulator reaches an acceptable level. As an example, the spacing of two magneto-optical spatial light modulators having a pixel pitch of 10 μm must be less than or equal to the level of 10-100 μm. This is almost impossible to achieve in a conventionally manufactured spatial light modulator because the thickness of the glass cover is 1 mm. Of course, a "sandwich" manufacturing method that enables only a thin separation layer between spatial light modulators can be included in one of the manufacturing processes. The fabrication method described in the Summary Manufacturing Procedure section can be applied to fabricate a device comprising two magneto-optical spatial light modulators with a small or minimal separation distance.

Figure 14 shows the Fresnel diffraction data plot, calculated for the diffraction produced by a 10 μm wide slit, varying the distance from the slit in a two-dimensional model, where the vertical axis is slit (z ), the horizontal axis is slit(x). The uniformly illuminated slit is located between -5 μm and +5 μm on the x-axis, and z is zero micrometers. The optical transmission medium used is to have a refractive index of 1.5, which may be a typical medium for compact devices. The selected light is red light having a vacuum wavelength of 633 nm. The green and blue wavelengths are smaller than the red light, so for the calculation of red light, among the three colors red, green and blue, the strongest diffraction effect is exhibited. Calculations can be performed using the product MathCad (RTM) software from Parametric Technology Corp., Needham, MA, USA. Figure 15 shows that a small portion of the intensity remains in the 10 μm wide range at the center of the slit as a function of the distance from the slit. At a distance of 20 μm from the slit, Fig. 15 shows that the intensity greater than 90% is still in the range of 10 μm wide of the slit. Therefore, in this two-dimensional model, less than 5% of the pixel intensity will be incident on each adjacent pixel. This is the result of a calculation with a zero boundary width between pixels. The actual boundary width between pixels is greater than zero, so the crosstalk problem will be lower than this calculated result in real systems. In Figure 14, the Fresnel diffraction pattern approaches the slit, for example 50 μm from the slit, and is somewhat approximate to the top-hat intensity function of the slit. Therefore, there is no wide diffraction characteristic near the slit. The wide diffraction characteristic is a characteristic of the far-field diffraction function of the high-hat type function, which is a conventionally known sinc squared function. The wide diffraction pattern shown in Fig. 14 is an example of a distance of 300 μm from the slit. This illustrates the advantage of placing two magneto-optical spatial light modulators close enough to control the diffraction effect, and the very close proximity of the two magneto-optical spatial light modulators is the functional version of the diffracted data graph, The far field characteristic will change to a more efficient functional version when it contains light that is close to the axis perpendicular to the slit. This advantage is contrary to the idea of using holographic technology, and the techniques used will tend to think When the light passes through the small aperture of the spatial light modulator, it will cause strong, large and unavoidable diffraction effects. Therefore, the conventional technique does not have the motivation to bring the two spatial light modulators together, and it is expected that such a way will cause an inevitable and serious pixel crosstalk problem due to the diffraction effect.

Figure 16 shows a contour plot of the intensity distribution as a function of distance from the slit. The plot of the contour is on a logarithmic scale, not a linear scale. Ten contour lines were used, all including a range of 100 intensity factors. For a slit width of 10 μm, a large degree of intensity distribution boundary is clear in the range of about 50 μm from the slit.

In another embodiment, the problem of crosstalk in the second magneto-optical spatial light modulator can be mitigated by reducing the pixel aperture area of the first magneto-optical spatial light modulator.

(2) The second method is to use a lens array between the two spatial light modulators, as shown in Figure 17. A better approach is to have the number of lenses equal to the number of pixels in each spatial light modulator. The spacing of the two spatial light modulators and the spacing of the lens arrays can be slightly different to compensate for the difference in distance from the observer. Each lens images the pixels of the first spatial light modulator to the pixels corresponding to the second spatial light modulator, as shown by beam 171 in FIG. Similarly, there will be light passing through adjacent lenses, which may cause crosstalk, as shown by beam 172. This can be ignored if its intensity is low enough, or if its direction is sufficiently different to make it impossible to reach the virtual observer window.

The numerical aperture (NA) of each lens must be large enough to image a pixel with sufficient resolution. As an example, for a resolution of 5 μm, a numerical aperture of about 0.2 is required. This also means that if polyhedron is assumed, and if the spatial light modulator is spaced from the lens array by 10 [mu]m, the maximum distance between lens array 1704 and each spatial light modulator 1702, 1703 is approximately 25 [mu]m. It contains incident light 1701.

It is also possible to assign several pixels of each spatial light modulator to one of the lenses in the lens array. As an example, a group of four pixels of the first spatial light modulator can be imaged by a lens in the lens array to a group of four pixels in the second spatial light modulator. The number of lenses of such a lens array will be one quarter of the number of pixels in each spatial light modulator. This allows for the use of lenses with higher numerical apertures, thus enabling higher resolution imaging pixels.

(3) The third method is to reduce the pixel aperture of the first magneto-optical spatial light modulator 1802 as much as possible. From the viewpoint of diffraction, in the second spatial light modulator, the area illuminated by one pixel of the first spatial light modulator is the pixel aperture width D of the first magneto-optical spatial light modulator 1802. And the diffraction angle is determined, as shown in Figure 18. In Fig. 18, d is the distance between two magneto-optical spatial light modulators (MOSLM) 1801, 1802, and w is the minimum of two first-order diffractions (occurring at the zeroth class maximum) The distance between one side). This is assumed to be a diffraction of Fraunhofer, or a reasonable approximation of the Fraunhofer diffraction. It contains Incident Light 1801.

Reducing the aperture width D on the one hand reduces the direct projection range of the central portion of the illumination area, as indicated by the dashed line in FIG. On the other hand, the diffraction angle increases as the diffraction angle is proportional to 1/D in the Fraunhofer diffraction. This increases the width of the illumination area on the second magneto-optical spatial light modulator. w. The full width of the illumination area is w. In the Fraun and Fiji diffraction methods, D can be determined such that it can minimize w by the equation w=D+2dλ/D given the separation d, which is from the Fraunhofer diffraction The distance between the two first-order minimums is derived.

For example, if λ is 0.5 μm, d is 100 μm, and w is 20 μm, a minimum value of D of 10 μm can be obtained. However, in this example, the Frang and Fiji methods may not be a good approximation. This example illustrates the use of a magneto-optical spatial light modulator. The distance is used to control the diffraction process of the Fraun and Fier diffraction methods.

(4) The fourth method uses a fiber optic panel to image the pixels of the first spatial light modulator to the pixels of the second spatial light modulator. The fiber optic panel is composed of two-dimensionally arranged parallel fibers. The length of the fiber and the thickness of the panel are typically a few millimeters, and the diagonal length of the panel surface is as long as several inches. As an example, the spacing of the fibers can be 6 μm. Edmund Optics Inc. of Barrington, New Jersey, USA has sold fiber optic panels with such fiber spacing. Each fiber directs light from one end of it to the other. Therefore, the image at one end of the panel is transmitted to the other end, and has high resolution and does not require a focusing element. Such a panel acts as a separation layer between the two spatial light modulators. Multimode fiber is more suitable than single mode fiber because multimode fiber has better coupling efficiency than single mode fiber. When the refractive index of the fiber core matches the refractive index of the liquid crystal, the best coupling efficiency is obtained because it minimizes Fresnel back reflection losses.

There is no additional cover glass between the two spatial light modulators. Light passing through the first magneto-optical spatial light modulator pixel is directed to a pixel corresponding to the second magneto-optical spatial light modulator. This minimizes crosstalk from neighboring pixels. The panel transmits the light distribution at the output of the first spatial light modulator to the input of the second spatial light modulator. On average, each pixel should have at least one fiber. If, on average, each pixel is less than one fiber, the resolution of the spatial light modulator will be lost, resulting in reduced image quality for display in holographic display applications.

Figure 10 shows an example of a tight alignment of the amplitude and phase information used to encode the hologram. 104 is a lighting device for providing illumination of a planar area, wherein the illumination is sufficiently homogenous to enable generation of a three-dimensional image. An example of an illumination device for a large area image hologram is presented in US 2006/250671. Like 104 The device may take the form of an array of white light sources, such as a cold cathode fluorescent lamp or emitted light as a white light emitting diode incident on the focusing system, wherein the focusing system may be compact, such as a lenticular array or microlens array 100. . Alternatively, the light source for 104 may be comprised of red, green, and blue lasers, or may be comprised of red, green, and blue light emitting diodes that emit sufficient tonal light. However, compared to laser sources, non-laser sources (eg, light-emitting diodes, organic light-emitting diodes, cold cathode fluorescent lamps) having sufficient spatial coherence are preferred. Laser light sources have some disadvantages, such as laser spots that can cause laser spots on holographic reconstruction, are relatively expensive, and can damage the omnidirectional display of the viewer or the eyes of the omni-directional display device.

The total thickness of elements 104, 100-103, and 109 can be on the order of a few centimeters or less. Element 101 may comprise a color filter array such that pixels of colored light (e.g., red, green, and blue light) are directed toward element 102, although a color filter is not required if a colored light source is used. Element 102 is a photo-biasing element or a set of photo-biasing elements. Element 103 is a magneto-optical spatial light modulator that encodes phase information. Element 109 is a magneto-optical spatial light modulator that encodes amplitude information. Elements 103 and 109 each comprise a photo-biasing element or a set of photo-biasing elements. Each element of component 103 (represented herein as 107) will be aligned with the corresponding component of component 109 (here indicated at 108). However, although the elements 103 and 109 have the same lateral spacing or spacing, the element size in element 103 will be less than or equal to the element in element 109, as the light exiting element 107 precedes element 108 of element 109, typically The ground will experience some diffraction. The encoding order of amplitude and phase can be reversed as shown in FIG.

A viewer located at a distance 106 from the device containing the compact hologram generator 105 can view the three-dimensional image from the direction of 105. Arranging elements 104, 100, 101, 102, 103 and 109 to form a physical connection as previously described, A compact hologram generator 105 can be formed. The optical components described in Section B can be included in the compact hologram generator 105 as can be seen in the prior art.

E. A large-magnification three-dimensional image display device comprising a tight combination of one or two magneto-optical spatial light modulators and having a target holographic reconstruction

Fig. 19 shows a large-magnification three-dimensional image display device in which a constituent element includes a close combination of one or two magneto-optical spatial light modulators and has a target holographic reconstruction. The components of this device include a close combination of a magneto-optical spatial light modulator and a coherent compact light source. This combination produces a three-dimensional image under appropriate illumination and can be viewed in a virtual observer window. Figure 19 is labeled as observed in OW) and this device component can be integrated, for example, in a personal digital assistant or mobile phone. As shown in FIG. 19, the close combination of the spatial light modulator and the well-toned compact light source includes a light source array 1901, a spatial light modulator MOSLM, and a lens array 1902. The spatial light modulator in Figure 19 contains a close combination of one or two magneto-optical spatial light modulators.

In a simple example, the array of light sources can be formed in the following manner. A single source, such as a monochromatic light-emitting diode, is placed adjacent to the array of apertures to illuminate the aperture. If the aperture is a slit of a one-dimensional array, the light transmitted by the slit will form a one-dimensional array of light sources. If the aperture is a circle of a two-dimensional array, the illuminated set of circles forms a two-dimensional array of light sources. A typical aperture width is about 20 μm. Such an array of light sources is suitable for producing an observer window for one eye.

In Fig. 19, the light source array is disposed at a distance from the lens array u. The array of light sources can be the light source of element 10 in Figure 1, and can optionally include element 12 of Figure 1. Specifically, each light source in the array of light sources is placed The distance from the lens u corresponding to its length in the lens array. In a preferred embodiment, the array of light sources is parallel to the plane of the lens array. The spatial light modulator can be located on either side of the lens array. The distance between the virtual observer window and the lens array is v. The lens in the lens array is a condensing mirror, and the focal length f is given by f = 1 / [1/u + 1 / v]. In a preferred embodiment, the value of v is in the range of 300 mm to 600 mm. In a more preferred embodiment, v is approximately 400 mm. In a preferred embodiment, the value of u is in the range of 10 mm to 30 mm. In a more preferred embodiment, the value of u is approximately 20 mm. The amplification factor M is determined by v/u. M is a factor that is modulated by the spatial light modulator and is magnified in the virtual observer window. In a preferred embodiment, the value of M is in the range of 10 to 60. In a more preferred embodiment, M is about 20. In order to achieve such an amplification factor to achieve good holographic image quality, it is necessary to accurately align the light source array with the lens array. In order to maintain a precise alignment and maintain the distance between the array of light sources and the array of lenses, the device components need to have very good mechanical stability until the lifetime of the components is exceeded.

The virtual observer window can be either traceable or untrackable. If the virtual observer window is traceable, a particular light source in the array of light sources is activated depending on the desired virtual observer window position. The activated light source illuminates the spatial light modulator and is imaged by the lens array to the viewer plane. For each lens in the lens array, at least one light source in the array of light sources is activated. Such tracking is quasi-continuous. If u is 20 mm and v is 400 mm, if the pixel pitch is 20 μm, a virtual observer window having a lateral increment of 400 μm can be tracked. Such tracking is quasi-continuous. If u is 20 mm and v is 400 mm, then f is approximately 19 mm.

The light source in the array of light sources may only have partial spatial homology. Partial homology can lead to fuzzy target point reconstruction. If u is 20mm and v is 400mm, if the width of the light source is 20μm, reconstruction of the target point from the display 100mm Will have a lateral blur of 100μm. This is sufficient for the resolution of the human visual system.

It is not necessary to have any significant mutual homology between the light passing through the different lenses in the lens array. The need for coherence is limited to each single lens in the lens array. Therefore, the resolution of the reconstruction target point is determined by the pitch of the lens array. For the human visual system, the typical lens spacing will be 1 mm to ensure adequate resolution.

The virtual observer window is a diffractive class that limits the Fourier spectrum of the information encoded in the spatial light modulator. If the spatial light modulator has a pixel pitch of 20 μm, the virtual viewer window will have a width of 10 mm wide at a wavelength of 500 nm. The virtual observer window can utilize space or time multiplex to piece together several virtual observer windows into an expanded virtual observer window. In the case of spatial multiplexing, additional optical components such as beam splitters may be required.

Color hologram reconstruction can be achieved by time multiplexing. The red, green, and blue pixels of the color organic light-emitting diode display are sequentially activated by synchronous re-encoding of the spatial light modulator, which has calculations for red, green, and blue optical wavelengths. Full picture.

An eye position detector may be included in the device component forming the display for detecting the position of the observer's eyes. The eye position detector is connected to a control unit that is used to control the activation of the light source in the array of light sources.

The calculation of the hologram image encoded on the spatial light modulator is preferably performed by an external coding unit because it requires a higher computational power. The display data is then transmitted to a personal digital assistant or mobile phone to display a three-dimensional image of the hologram.

F. Planar projection machine comprising a close combination of one or two pairs of magneto-optical spatial light modulators

In addition to projecting light into several virtual viewer windows, light emitted from the holographic display can also be projected onto a screen or wall or some other surface. Therefore, the three-dimensional display device in a mobile phone or a personal digital assistant can also be used as a pocket projector. Any other three-dimensional display device comprising a close combination of one or two pairs of magneto-optical spatial light modulators can also be used as a projector.

The quality of the holographic projection can be improved by using a spatial light modulator to modulate the amplitude and phase of the incident light. Therefore, a complex-valued hologram can be encoded on a spatial light modulator, allowing for better quality of reconstructed images on the screen or wall.

A close combination of one or two pairs of magneto-optical spatial light modulators can be used as a spatial light modulator in a projector. Since the size of this combination is tight, the projector will also be tight. The projector can even be the same device as a mobile phone or a personal digital assistant: it can be switched between "3D display" and "projector" modes.

Compared to conventional 2D projectors, holographic 2D projectors have the advantage of not requiring a projection lens and the projected image can be focused at all distances in the optical far field. Conventional holographic two-dimensional projectors, such as those described in WO2005/059881, use a single spatial light modulator, so that complex modulation cannot be performed. The holographic two-dimensional projector described herein will be able to perform complex modulations and thus have excellent image quality.

G. Spatial multiplexing and two-dimensional coding of the observer window

This embodiment relates to the spatial multiplexing of virtual observer windows (VOWs) for holographic displays, combined with the use of two-dimensional encoding. In addition, the holographic display can be like Same as described in Sections A, B, C or D, or as any conventional holographic display.

It is known that several observer windows (e.g., a virtual observer window for the left eye and a virtual observer window for the right eye) can be generated using spatial or temporal multiplexing. With regard to spatial multiplexing, two virtual observer windows are generated at the same point in time and are distinguished by a beam splitter, similar to an autostereoscopic display, as described in WO 2006/027228. With regard to time multiplex, the virtual observer window is generated sequentially in time.

However, conventional hologram display systems have some drawbacks. For spatial multiplexing, the illumination system used is spatially non-coherent in the horizontal direction and is based on a horizontal line source and a lenticular array, as shown in Figure 4 from the prior art WO 2006/027228. This has the advantage of utilizing known autostereoscopic display technology. However, its disadvantage is that it is impossible to produce a holographic reconstruction in the horizontal direction. Instead, so-called 1D encoding is used, which allows hologram reconstruction and moving parallax to be generated only in the vertical direction. Thus, the vertical focus is in the plane of the reconstructed object and the horizontal focus is in the plane of the spatial light modulator. These astigmatisms reduce the quality of spatial vision, meaning that it reduces the quality of holographic reconstruction received by the viewer. Similarly, time multiplex systems have the disadvantage that they require fast spatial light modulators, and there are no such fast spatial light modulators in all of the display sizes, even if they are found to be excessively expensive.

Only two-dimensional coding can provide holographic reconstruction in both horizontal and vertical directions, so two-dimensional coding will not produce astigmatism, and astigmatism will reduce the quality of spatial vision, which means reducing the quality of holographic reconstruction received by the viewer. Therefore, the purpose of this embodiment is to combine two-dimensional coding to achieve spatial multiplexing of virtual observer windows.

In this embodiment, illumination with horizontal and vertical local spatial coherence is combined with a beam splitter that separates the beam into a beam for the left-eye virtual observer window and a beam for the right-eye virtual observer window. . Therefore, diffraction on the beam splitter must be considered. The beam splitter can be a tantalum array, a second lens array (eg, a static array or a variable array, as shown in FIG. 20), or a barrier mask. Figure 20 includes incident light 2001, a pit filled with liquid crystal 2002, a well-aligned liquid crystal 2003, a host material 2004, and an electric field 2005, 2006.

An example of this embodiment is shown in Figure 22. Figure 22 is a schematic diagram of a holographic display comprising a light source of a two-dimensional array of light sources, a lens of a two-dimensional lens array, a spatial light modulator, and a beam splitter. The beam splitter splits the light exiting the spatial light modulator into two beams that illuminate the virtual observer window (VOWL) for the left eye and the virtual observer window (VOWR) for the right eye. In this example, the number of light sources is one or more; the number of lenses is the same as the number of light sources.

In this example, the beam splitter is after the spatial light modulator. The positions of the beam splitter and the spatial light modulator can also be interchanged.

Figure 23 shows a plan view of this embodiment in which a 稜鏡 array is used as a beam splitter. The illumination device comprises a two-dimensional array of two elements (LS1, LS2, ... LSn) and a two-dimensional lens array (L1, L2, ... Ln) of n elements, which are only shown in Figure 23. Two light sources and two lenses. Each light source is imaged to the viewer plane using its corresponding lens. The spacing of the array of light sources and the spacing of the lens arrays are such that images of all of the light sources can simultaneously appear in the viewer plane, ie, the plane containing the two virtual viewer windows. In Figure 23, the left-eye virtual observer window (VOWL) and the right-eye virtual observer window (VOWR) are not displayed because they are in It is beyond the position of the figure and is on the right side of the figure. Additional field lenses can be added. In order to provide sufficient spatial coherence, the pitch of the lens array is similar to the typical size of a sub-image, i.e., one to several millimeters. When the light source is small or a point source, and when a two-dimensional lens array is used, the illumination is horizontal and vertical spatially tonal in each lens. The lens array can be refractive, diffractive or holographic. The beam splitter 2301 is included therein.

In this example, the beam splitter is a one-dimensional array of vertical turns. Light incident on one slope of the 稜鏡 is deflected to the left eye virtual observer window (to VOWL), and light incident on the other slope of the 稜鏡 is deflected to the right eye virtual observer window (to VOWR) . Light rays generated from the same LS and the same lens are also homologous to each other after passing through the beam splitter. Therefore, two-dimensional encoding with vertical and horizontal focusing and vertical and horizontal moving parallax is possible.

The hologram is encoded on a spatial light modulator using two-dimensional coding. The holograms for the left and right eyes are line-by-line interlaced, meaning interlaced coding for holographic information for the left and right eyes. It is better to have a line containing the left eye hologram information and a line containing the right eye hologram information under each armpit. Another method may also be a row with two or more holograms under each bevel of the cymbal, for example three rows for the left eye virtual observer window, and then three rows for the right eye virtual observer Windows. The beam splitter may have the same pitch as the spatial light modulator, or an integer (eg, two or three) multiples, or, in order to allow for perspective shortening, the beam splitter may be spaced apart by a spatial light modulator The spacing is slightly smaller, or slightly smaller than its integer (for example, two or three) multiples.

Light emitted from a line with a full image of the left eye reconstructs the target for the left eye and illuminates the left eye virtual observer window (VOWL); the light emitted from the line with the right eye hologram is heavy Construct a target for the right eye and illuminate the right eye virtual observer window (VOWR). Therefore, each eye will receive an appropriate reconstruction. If the spacing of the 稜鏡 array is sufficiently small, the eye cannot resolve the 稜鏡 structure and the 稜鏡 structure does not interfere with the reconstruction of the hologram. Each eye will see a reconstruction with full focus and full motion parallax, and no astigmatism.

When the dimming beam illuminates the beam splitter, there will be diffraction on the beam splitter. The beam splitter can be viewed as a diffraction grating that produces multiple diffraction levels. The oblique bevel has the effect of a blazed grating. For blazed gratings, the maximum intensity is directed to a particular diffraction class. For a tantalum array, a maximum intensity will be directed from one slope of the jaw to a diffractive stage at the virtual observer window of the left eye, and the other maximum intensity will be directed from the other slope of the pupil to the virtual observer window in the right eye. Another diffractive class of position. More precisely, the maximum intensity of the enveloping sinc-squared function is shifted to these positions, while the diffractive class is in a fixed position. The 稜鏡 array produces a maximum value of the intensity-encapsulated sinc-squared function at the position of the left-eye virtual observer window, and produces the maximum value of another intensity-packed sinc-squared function at the position of the right-eye virtual observer window. The intensity of the other diffraction classes will be small (meaning that the maximum value of the sinc squared intensity function is narrow) and will not cause interference crosstalk because the fill factor of the 稜鏡 array is large, for example Close to 100%.

As can be seen in the prior art, in order to provide a virtual observer window to two or more observers, by using a more complex array of cymbals (eg, two types of cymbals, having the same apex angle (apex) Angles), but varying degrees of asymmetry, sequentially adjacent to each other to produce multiple virtual observer windows. However, using a static 稜鏡 array is not able to track the observer individually.

In another example, more than one light source can be used per lens. The additional light source for each lens can be utilized to create additional virtual observer windows that are provided to other viewers. This is an example described in WO 2004/044659 (US 2006/0055994), which uses an example of a lens and m light sources for m observers. Another example of this is to use m light sources per lens and double spatial multiplexing to generate m left-eye virtual observer windows and m right-eye virtual observer windows for m observers. The m light sources per lens are in a corresponding manner of m to 1, where m is an integer.

This is followed by an example of this embodiment. Use a 20-inch screen size with the following parameter values: observer distance 2m, pixel pitch 69μm vertical, 207μm horizontal, using Burckhardt encoding, and optical wavelength 633nm. The Bookhart code is in the vertical direction with a sub-pixel pitch of 69 μm and a virtual observer window of 6 mm height (vertical period). Ignoring the perspective shortening, the vertical 稜鏡 array has a spacing of 414 μm, which is the line with two spatial light modulators under each full 稜鏡. Therefore, the horizontal period in the observer plane is 3 mm. This is also the width of the virtual observer window. This width is less than the ideal pupil size of the eye of about 4 mm in diameter. In another similar example, if the spatial light modulator has a 50 μm smaller pitch, the virtual viewer window will have a width of 25 mm.

If the adult eye is separated by 65 mm (which is typical), the 稜鏡 must deflect the light by ±32.5 mm so that the light intersects the plane containing the virtual observer window. More precisely, the maximum value of the intensity package sinc-squared function needs to be skewed by ±32.5 mm. This corresponds to an angle of ±0.93° for an observer distance of 2 m. For enthalpy with a refractive index n = 1.5, a suitable 稜鏡 angle is ± 1.86 °. The 稜鏡 angle is defined as the angle between the base and the skewed edge.

For the level in the 3 mm observer plane, the position of the other eye is at a distance of approximately 21 diffraction stages (ie 65 mm divided by 3 mm). Thus, the crosstalk between the left eye virtual viewer window and the right eye virtual viewer window caused by the higher diffractive class of another virtual observer window is negligible.

In order to implement tracking, the source tracking is a simple tracking method, which means to adjust the position of the light source. If the spatial light modulator is not on the same plane as the 稜鏡 array, there will be a disturbance between the spatial light modulator pixels and 稜鏡 caused by the parallax associated with the lateral offset. This will probably cause disturbing crosstalk. The pixels in the above 20-inch screen size example may have a fill factor of 70% in the direction perpendicular to the axis formed by each of the tips of the crucible, that is, the area of the pixel having a size of 145 μm on each side. And an inactive area of 31 μm. If the construction area of the 稜鏡 array is toward a spatial light modulator, the separation between the 稜鏡 array and the spatial light modulator may be approximately 1 mm. The horizontal tracking range without crosstalk will be ±31μm/1mm * 2m=±62mm. If small crosstalk is tolerable, the range of tracking will be even larger. This tracking range is not very large, but it is sufficient for some tracking, reducing the restrictions on the viewer, such as limiting the position of his/her eyes.

The parallax between the spatial light modulator and the 稜鏡 array can be avoided. The better way is to integrate the 稜鏡 array or integrate it directly into the spatial light modulator (such as refraction, diffraction or full Image 稜鏡 array). This will be a special component for the product. Another option is to move the 稜鏡 array laterally mechanically, although this is less recommended because moving the mechanical structure can make the device more complicated.

Another key issue is the fixed separation between the virtual observer windows as determined by the 稜鏡 angle. This is not a standard observer for eye separation or z-tracking May cause trouble. One of the solutions is to use an assembly comprising encapsulated liquid-crystal domains, as shown in FIG. 21, which includes incident light 2101, liquid crystal alignment holes 2102, and liquid crystal filled holes 2103. The maximum twisted beam manipulation 2104, the body material 2105, and the transparent electrodes 2106, 2107. Then, the electric field can control the refractive index, as well as the skew angle. This solution can be combined with the 稜鏡 array to provide variable skew and fixed skew continuously, respectively. In another solution, the liquid crystal layer can be used to cover the structural edges of the tantalum array. Then, the electric field can control the refractive index, as well as the skew angle. If the virtual observer window has enough observers to allow different eye separations and z-track such a large width, then the variable skew component will not be needed.

A more complicated solution is to use a controllable array of enthalpy, such as an e-wetting array (as shown in Figure 24) or a liquid filled 稜鏡 (as shown in Figure 21). In Fig. 24, layer 159 having germanium elements includes electrodes 1517, 1518, pits filled with two separate liquids 1519, 1520, and direction 2401 of light propagation. Each liquid is a prismatic portion that fills a cavity. As an example, the liquid can be oil or water. The slope of the interface between the liquids 1519, 1520 is determined by the voltage applied to the electrodes 1517, 1518. If the liquids have different refractive indices, the beams will be biased, which is determined by the voltage applied to the electrodes 1517, 1518. Therefore, the 稜鏡 element 159 is equivalent to a controllable beam steering element. This is an important feature for the applicant's method to be applied to electronic holographic techniques that require tracking of the virtual observer window to the viewer's eyes. Patent application Nos. DE 102007024237.0 and DE 102007024236.2, filed by the applicant, describe the tracking of the virtual observer window to the observer's eye with a sputum element.

This is an embodiment for a compact handheld display. Seiko (RTM) Epson (RTM) Corporation of Japan has published a monochrome electronic address space light Modulators, such as the D4: L3D13U 1.3 inch screen size panel. Describe an example of using a D4:L3D13U LCD panel as a spatial light modulator. It has HDTV resolution (1920 x 1080 pixels), 15μm pixel pitch and 28.8mm x 16.2mm panel area. This panel is typically used for 2D image projection displays.

This example is for the calculation of the wavelength of 663 nm and the observer distance of 50 cm. In this amplitude-modulated spatial optical modulator, Detour-phase coding (Buckerhard coding) is used: three pixels are required to encode a complex number. The three associated pixels are arranged vertically. If the 稜鏡 array beam splitter is integrated into the spatial light modulator, the 稜鏡 array spacing is 30 μm. If there is a separation between the spatial light modulator and the 稜鏡 array, the spacing of the 稜鏡 array will be slightly different to cope with the perspective shortening.

The height of the virtual observer window is determined by the spacing used to encode a complex number of 3 * 15 μm = 45 μm and is 7.0 mm. The width of the virtual observer window is determined by the 30 μm pitch of the 稜鏡 array and is 10.6 mm. Both values are greater than the pupil of the eye. Therefore, if the virtual observer window is in the position of the eye, the hologram reconstruction can be seen in each eye. The holographic reconstruction is derived from a two-dimensionally encoded hologram, and therefore does not have the astigmatism problem inherent in the one-dimensional encoding described above. This ensures high spatial visual quality and high depth impression quality.

When the separation of the eyes is 65 mm, the 稜鏡 must be deflected by ±32.5 mm. More precisely, the maximum intensity of the package sinc-squared intensity function needs to be skewed by ±32.5 mm. This is equivalent to an angle of ±3.72° for an observer distance of 0.5 m. For a refractive index n = 1.5, a suitable 稜鏡 angle is ± 7.44 °. The 稜鏡 angle is defined as the angle between the base and the skewed edge.

For the level in the 10.6 mm observer plane, the position of the other eye is at a distance of about 6 diffraction stages (ie 65 mm divided by 10.6 mm). therefore, The crosstalk caused by the higher diffraction class is negligible because the 稜鏡 array has a high fill factor, meaning close to 100%.

This is an embodiment for a large display. The holographic display can be designed to use a phase modulated spatial light modulator with a 50 [mu]m pixel pitch and a 20 inch screen size. For applications such as television, the screen size can be quite close to 40 inches. The observer distance for this design is 2 m and the wavelength is 633 nm.

A complex number is encoded using two phase modulated pixels of the spatial light modulator. The two associated pixels are arranged vertically and the corresponding vertical spacing is 2 * 50 μm = 100 μm. The 稜鏡 array is integrated in the spatial light modulator, and the horizontal spacing of the 稜鏡 array is also 2 * 50μm = 100μm, because each 稜鏡 contains two slopes, and each slope is used for the spatial light modulator One line. This produces a virtual observer window of 12.7 mm width and height, and is larger than the pupil of the eye. Therefore, if the virtual observer window is in the position of the eye, the hologram reconstruction can be seen in each eye. The holographic reconstruction is derived from the two-dimensional coded hologram, so there is no astigmatism problem in the one-dimensional coding itself. This ensures high spatial visual quality and high depth impression quality.

When the separation of the eyes is 65 mm, the 稜鏡 must be deflected by ±32.5 mm. More precisely, the maximum value of the intensity package sinc-squared function needs to be skewed by ±32.5 mm. This is equivalent to an angle of ±0.93° for an observer distance of 2 m. For a refractive index n = 1.5, a suitable 稜鏡 angle is ± 1.86 °. The 稜鏡 angle is defined as the angle between the base and the skewed edge.

The above is an example in which the distance between the observer and the spatial light modulator is 50 cm and 2 m. In summary, this embodiment can be applied to a distance of between 20 cm and 4 m from the observer to the spatial light modulator. Screen size can be between 1cm (eg for mobile phones) The second screen is between 50 inches (for example for large size TVs).

Laser source

For compact holographic displays, RGB solid-state laser sources can be suitable sources, such as indium gallium arsenide (GaInAs) or indium gallium arsenide (GaInAsN) materials, because they are compact and highly Light directionality. Such light sources include RGB Vertical Cavity Surface Emitting Lasers (VCSELs) manufactured by Novalux (RTM) Inc., CA, USA. Such a light source can be provided as a single laser or laser array, although each light source can utilize a diffractive optical element to produce multiple beams. The beam can be transmitted in a multimode fiber because if the homology is too high for use in a compact hologram display, this can reduce the level of coherence and does not result in unwanted artifacts, such as laser classes. Dot pattern. The array of laser sources can be one or two dimensional.

Summary manufacturing process

Next, a summary of the manufacturing process of the apparatus of Fig. 2 will be described, but many variations on this procedure will be seen in the prior art.

In the manufacturing process of a device of Fig. 2, a transparent substrate is used. Such a substrate may be a rigid substrate, such as a boron germanium glass sheet of about 200 μm thick, or it may be a flexible substrate such as a polymer substrate such as polycarbonate, acrylic, poly. Polypropylene, polyurethane, polystyrene, polyvinyl chloride or the like. The computer layer in the display is made on glass, as described in the applicant's patent application No. GB 0709376.8, GB 0709379.2, which is incorporated herein by reference. Such a calculation circuit can be placed between the pixels of the display. This circuit is then covered by a transparent insulating film like (SiO ₂ ). The magneto-optical film is disposed on the transparent insulating film. A micro coil array is provided, corresponding to the pixels of the display. A similar procedure is described in WO2005/122479A2. The coil material can be a conductive material such as copper (Cu) or aluminum (Al). The coil array can be fabricated to have a low resistance and a large number of turns. As shown in Fig. 7, a cylindrical recess 71 corresponding to the depth of the magneto-optical film 72 is eroded into the magneto-optical film. As shown, a conductive material is disposed within the cylindrical recess 71 to implement the microcoil 81. It is worth noting that the recess can be realized by laser etching. An ultra-short pulsed laser with a period of one-quarter or one-billionth of a second pulse and high peak power limits the area of heat affected and causes the material removal process to be melted (ablation) Controlled, thus achieving very good magneto-optical film accuracy. One or a set of intermediate biasing layers are then produced. This is followed by another magneto-optical film on which another micro-coil array as described above is fabricated. Then another or a set of polarization layers. This completes the structure of two adjacent magneto-optical spatial light modulator devices. This is followed by an unnecessary beam steering element and a glass cover.

It is necessary for a layer having a sufficient thickness between the two magneto-optical spatial light modulator devices to ensure that the magnetic field in one magneto-optical spatial light modulator does not affect the other magneto-optical spatial light modulator efficacy. One or a set of intermediate biasing layers of sufficient thickness can be used to achieve this goal. However, if the one or a set of intermediate biasing layers are not thick enough, the thickness of the layer can be increased, for example using optical glue to combine the magneto-optical spatial light modulator device with a glass of sufficient thickness, or to provide another optical A transparent layer, such as an inorganic layer or a polymer layer. The other optically transparent layer may be an inorganic insulating layer such as silicon dioxide, silicon nitride or silicon carbide, or may be a polymerizable layer such as a ring. Oxygen resin (epoxy). Configuration can be done by sputtering or by chemistry The chemical vapour deposition is done (for inorganic insulating layers) or by printing or coating (for polymeric layers). In any event, magneto-optical spatial light modulator devices must not be too far apart to reduce unwanted optical crosstalk resulting in unwanted pixel crosstalk. For example, if the pixel width is 10 microns, the magneto-optical spatial light modulator layers should preferably be less than 100 microns apart. A magneto-optical spatial light modulator is configured to perform at least amplitude modulation; another magneto-optical spatial light modulator is configured to perform at least phase modulation.

The second magneto-optical spatial modulator portion of the device can be fabricated as a single component and then bonded to the first magneto-optical spatial modulator portion of the device, for example, to ensure a magneto-optical spatial light modulator There is a sufficiently separate layer of glass between the layers such that the magnetic field of each of the magneto-optical spatial light modulator layers does not affect the function of the other magneto-optical spatial light modulator layer. In which the second magneto-optical spatial modulator portion of the device is prepared by arranging additional material on the first magneto-optical spatial light modulator portion of the device, which aids in the second magneto-optical spatial light modulation The advantage of precise alignment between the pixels of the device and the pixels of the first magneto-optical spatial light modulator.

Fig. 9 shows an example of a device structure which can be manufactured by the above program or the like. In use, surface 909 illuminates light that is sufficiently concentrically visible to device structure 910 in Figure 9, such that a viewer at point 911 (some distance from the device, depending on the dimensions of the device) can see the three-dimensional image. The layers in the device, from 90 to 901, are not related to each other. Layer 90 is a base layer, such as a glass layer. Layer 91 is a computer layer in the display that may be omitted in some embodiments. Layer 92 is an insulating layer. Layer 93 is a magneto-optical film layer. Layer 94 is a micro coil array layer. Layer 95 is one or a set of biasing layers. Layer 96 is an optional layer to separate the two microcoil arrays to the required standard. Layer 97 is another magneto-optical film layer. Layer 98 is another micro-coil array layer. Layer 99 is another or another set of biasing layers. Layer 900 is a beam steering element Array layer. Layer 901 is a plane that covers the material, such as glass. During fabrication, the fabrication of device 910 can begin with substrate layer 90, with each layer being disposed in sequence until the last layer 901 is added. The advantage of the above procedure is that it can help the alignment of the layers of the structure to be more precise. Alternatively, the layer can be fabricated into two or more sections that are joined together by a sufficient degree of alignment.

According to embodiments, it is very important to maintain the minimum birefringence at a minimum for the manufacture of the device, such as unwanted stress-induced birefringence. Stress induced birefringence causes a linear or circularly polarized state of light to change to an elliptically polarized state of light. In devices with ideal linear or circularly polarized states of light, the presence of ellipsometric state of light reduces contrast and color fidelity, and thus reduces device performance.

However, the embodiments described herein emphasize the continuous encoding of amplitude and phase in a magneto-optical spatial light modulator, due to the development of conventional techniques, the continuous weight coding of any two unequal amplitude and phase combinations, principles Both can be used to encode holographic pixels, where the two combinations are not equal to any real multiple, but do not contain complex numbers (except real numbers). This reason is that the vector space of the possible holographic coding of the pixel will be extended in the vector space perception by any two unequal amplitude and phase combinations, where the two combinations are equal to any real multiple, but not included. Plural (except real numbers).

In the illustrations shown herein, the relevant dimensions are not necessarily to scale.

The technology disclosed in this case can be implemented by a person familiar with the technology, and its unprecedented practice is also patentable, and the application for patent is filed according to law. However, the above embodiments are not sufficient to cover the scope of patents to be protected in this case. Therefore, the scope of the patent application is attached.

Introduction to technology

The following sections provide an introduction to several important techniques that will be used in the systems implementing the above embodiments.

In the conventional holographic technique, the observer can see the holographic reconstruction of the target (this can be a changing scene); the distance between him and the hologram is not necessarily related. In a typical optical arrangement, the reconstruction is on or near the imaging plane of the source that illuminates the hologram, so it is on the Fourier plane of the hologram. Thus, the reconstruction has the same far-field light distribution as the reconstructed real object.

An earlier system (described in WO 2004/044659 and US 2006/0055994) defines a very different arrangement in which the reconstructed object is not at all or near the Fourier plane of the hologram. Instead, the area of the virtual observer window is in the Fourier plane of the hologram; the correct reconstruction can only be seen when the observer places his eyes in this position. The hologram is encoded on a liquid crystal display (or other type of spatial light modulator) and illuminated so that the virtual observer window becomes a Fourier transform of the hologram (hence, it is a Fourier directly imaged on the eye) Convert); then, the reconstructed object will be a Fresnel transform of the hologram because it is not in the focal plane of the lens. It is defined by the near-field light distribution (using a spherical wavefront as a model, which is different from the plane wavefront assigned by the far field). This reconstruction can occur anywhere in the virtual viewer window (as described above, in the Fourier plane of the hologram) and the liquid crystal display, or even as a virtual target behind the liquid crystal display.

Such an approach produces several results. First, the basic limitation that designers of holographic imaging systems face is the pixel pitch problem of liquid crystal displays (or other types of light modulators). The designer's goal is to create a large hologram reconstruction using a liquid crystal display with pixel pitch that is commercially available and reasonably priced. But in the past this was impossible because of the following reasons. The periodic spacing between adjacent diffraction orders in the Fourier plane is determined by λ D / p , λ is the wavelength of the illumination light, D is the distance from the hologram to the Fourier plane, and p is the pixel pitch of the liquid crystal display. But in conventional holographic displays, the reconstructed object is in the Fourier plane. Therefore, the reconstructed object must remain less than the periodic interval; if it is large, its edges will be blurred from the adjacent diffraction class to the reconstruction. This will result in very small reconstructed objects - typically only a few cm wide, even with expensive and professional small pitch displays. But with the current method, the virtual observer window (which is set in the Fourier plane of the hologram as described above) only needs to be as large as the pupil of the eye. Therefore, even a liquid crystal display having only a medium pitch size can be used. And because the reconstructed object can completely fill the frustum between the virtual observer window and the hologram, it can be very large, that is, it can be much larger than the periodic interval.

There is another advantage. When calculating the hologram, start with an understanding of the reconstructed object - for example you might have a 3D image of the car. That file will describe how objects should be seen from several different viewing positions. In the conventional holographic technique, the holograms required to generate the car's reconstruction are obtained directly from the 3D image archives in the computationally intensive program. But the virtual observer window approach will be able to adopt a different and more computationally efficient technique. Starting with a plane that reconstructs the object, we can calculate the virtual observer window because this is the Fresnel transformation of the target. Next, we perform this on all target planes and sum the results to produce a cumulative Fresnel transition; this defines the wave field that traverses the virtual observer window. We then calculate the hologram as the Fourier transform of this virtual observer window. Although the virtual observer window contains all the information about the object, only a single planar virtual observer window must be converted to an hologram, rather than a multi-plane object. If the conversion from the virtual observer window to the hologram is not a single step, but a repeated conversion, This is particularly advantageous, such as the Iterative Fourier Transformation Algorithm. Each of the repeated steps only includes a Fourier transform of a single virtual observer window, rather than one for the entire object plane, which can greatly reduce the amount of computation.

Another striking result of the virtual observer window approach is that all the information needed to reconstruct a given target point is contained in a relatively small area of the hologram; in contrast, in the conventional holographic technique, reconstruction The information for a given target point is distributed throughout the hologram. Because we need to encode the information into a very small area of the hologram, this shows that the amount of information we need to process and encode is much lower than the conventional holographic technique. This also shows that even for the instant image holography technology, it is still possible to use a conventional computing device, such as a digital signal processor (DSP) whose price and performance are in line with the mass market.

However, there are still some lower than expected results. First, it is important to view the distance of the hologram - using this method to encode and illuminate the hologram, only when the eye is in the Fourier plane of the hologram, will the correct reconstruction be seen; As shown in the figure, viewing distance is not very important. However, there are a variety of methods that can be used to reduce this Z-sensitivity or design.

Similarly, since such a method is used to encode and illuminate the hologram, the correct hologram reconstruction can only be achieved from a precise and small viewing position (ie, accurately defining Z, as described above, and X and Y coordinates). Observed, so eye tracking may be required. Same as Z sensitivity, there are a variety of methods that can be used to reduce X and Y sensitivity, or designs related to this, for example, as pixel pitch is reduced (because it will follow the manufacturing progress of liquid crystal displays), virtual The size of the viewer window will increase. In addition, more efficient coding techniques, such as Kinoform encoding, facilitate the use of a larger portion of the periodic interval as a virtual observer. Window to increase the virtual observer window.

The above description assumes that we are dealing with a Fourier hologram. The virtual observer window is in the Fourier plane of the hologram, meaning the imaging plane of the light source. One of the advantages is that non-diffracted light is focused in a so-called DC-spot. This method can also be used in a virtual observer window that is not a Fresnel hologram of the imaging plane of the light source. However, care must be taken that non-diffracted light is not visible as the interference background. Another point to note is that the word conversion should be interpreted to include any mathematical or computational method that is equal or similar to the transformation describing light propagation. Conversion is just a procedure to approximate the entity, more precisely defined by the Maxwellian wave propagation equation; Fresnel and Fourier transform are second-order approximations, but have the following advantages (i) because they are algebraic relative to the differentiation They can be processed in a computationally efficient manner and (ii) can be accurately implemented on an optical system.

Further details are described in the contents of US patent application 2006-0138711, US 2006-0139710 and US 2006-0250671, the disclosures of each of which are incorporated herein by reference.

Terminology used in the content Computer-generated hologram

According to the implementation, the computer generated image hologram (CGH) is a hologram calculated from the scene. The computer-generated image hologram can contain complex values that represent the amplitude and phase of the light waves needed to reconstruct the scene. Computer-generated image holograms can be calculated using, for example, coherent ray tracing, interference between simulated scenes and reference waves, or Fourier or Fresnel conversion.

coding

Encoding is a program in which the control values of the image hologram of a spatial light modulator (eg, its constituent elements) are provided. In general, holograms contain complex values that represent amplitude and phase.

Coding area

The coding region is typically a finite region on the image hologram space in which hologram data for a single scene point is encoded. The spatial limitation is achieved by using steep truncation or by smooth transformation, which is achieved by Fourier transform from the virtual observer window to the image hologram.

Fourier transform

Fourier transform is used to calculate the propagation of light in the far field of a spatial light modulator. Wavefronts are described using plane waves.

Fourier plane

The Fourier plane contains the Fourier transform of the light distribution on the spatial light modulator. Without any focusing lens, the Fourier plane is infinite. If there is a focusing lens on the light path close to the spatial light modulator, then the Fourier plane will be equivalent to the imaged plane containing the light source.

Fresnel conversion

Fresnel conversion is used to calculate the propagation of light in the near field of a spatial light modulator. The wavefront is described as a spherical wave. The phase factor of the light wave contains an item that is affected twice by the lateral coordinate.

Frustum

The virtual frustum is constructed between the virtual viewer window and the spatial light modulator and extends beyond the spatial light modulator. The scene is reconstructed in this frustum. The size of the reconstructed scene is limited by this frustum and is not limited by the periodic spacing of the spatial light modulator.

Imaging optics

Imaging optics are one or more optical elements, such as lenses, lenticular arrays, or microlens arrays, used to form an image of one or more light sources. As used herein, non-imaging optics means that when constructing a holographic reconstruction, imaging optics are not used to form a plane between the Fourier plane and one or two spatial light modulators to form one or two spatial light. The imaging of the modulator, as described in the text.

Light system

The light system can include a coherent light source, such as a laser, or a partially coherent light source, such as a light emitting diode. The temporal and spatial coherence of some homogenous light sources must be sufficient to promote good scene reconstruction, that is, the spectral linewidth and lateral extension of the radiating surface must be sufficiently small.

Microlens array

The microlens array provides local homology over a small area of the display, which is the only part of the display that encodes information for reconstructing a given point of the object. Local homology is typically found in one microlens of the array. Secondary hologram (ie The coding area) may be larger than a single microlens. Next, the reconstruction point will be a number of reconstructed incoherent superpositions from different microlenses. Typically, the sub-image (ie, the coding region) will extend in one or two microlenses.

Virtual Observer Window (VOW)

The virtual observer window is a virtual window in the viewer's plane, from which the reconstructed three-dimensional object can be seen. The virtual observer window is a Fourier transform of the hologram and is placed in a periodic interval to avoid observing multiple object reconstructions. The size of the virtual observer window must be at least the size of the pupil of the eye. If there is a system for eye tracking and at least one virtual observer window is placed at the observer's eye position, the virtual observer window can be much smaller than the observer's lateral movement range. This promotes the use of spatial resolutions with medium resolution and small periodic spacing. The virtual observer window can be thought of as a keyhole through which a reconstructed three-dimensional object can be seen, either a virtual viewer window for each eye, or a virtual observer window shared by two eyes.

Periodic interval

If the computer-generated image hologram is displayed on a spatial light modulator that contains individually addressable components, the computer-generated image hologram will be sampled. This sampling produces a periodic repetition of the diffractive pattern. The periodic interval is λD/p, where λ is the wavelength, D is the distance from the hologram to the Fourier plane, and p is the pitch of the spatial light modulator elements.

reconstruction

The spatial light modulator that encodes the full image and is illuminated reconstructs the original light distribution. This light distribution is used to calculate the hologram. Ideally, the observer has no way to distinguish the original light distribution from the reconstructed light distribution. In most hologram displays, it will be heavy The light distribution of the scene is built. In our display, the light distribution in the virtual observer window is reconstructed instead.

Scenes

The reconstructed scene is a three-dimensional light distribution that is real or computer generated. In a special case, it can also be a two-dimensional light distribution. The scene can constitute a variety of fixed or moving objects arranged in space.

Spatial Light Modulator (SLM)

A spatial light modulator is used to modulate the wavefront of incoming light. An ideal spatial light modulator should have the ability to represent any complex value, that is, to control the amplitude and phase of the light wave, respectively. However, a typical conventional spatial light modulator can only control one of the characteristics, not amplitude or phase, and has an adverse effect on the other characteristic.

10‧‧‧Lighting device

11‧‧‧Polarized components

12‧‧‧Color Filter Array

13‧‧‧Magnetic space light modulator

14‧‧‧Partialized film

15‧‧‧Full image generator

16‧‧‧ points

20‧‧‧Lighting device

21‧‧‧Polarized components

22‧‧‧Color Filter Array

23‧‧‧Magnetic space light modulator

24‧‧‧ points

25‧‧‧Full image generator

26‧‧‧Polarized components

27‧‧‧Magnetic space light modulator

28‧‧‧Photo-biased layer

1101‧‧‧ Focusing components

1102‧‧‧ Focusing components

1103‧‧‧ Focusing components

1104‧‧‧ Focus System

1105‧‧‧First class

1106‧‧‧The zero class

1107‧‧‧negative class

51‧‧‧Bottom glass substrate

52‧‧‧Computer in the display

53‧‧‧layer with coil

54‧‧‧Magnetic photonic crystal layer

55‧‧‧ polarizer

56‧‧‧Magnetic photonic crystal layer

57‧‧‧layer with coil

58‧‧‧ polarizer

59‧‧‧稜鏡 Components

510‧‧‧ glass substrate

511‧‧ ‧ pixels

512 ‧ ‧ pixels

513‧‧ ‧ pixels

514‧‧‧ coil

515‧‧‧Feeding device

516‧‧‧ coil

517‧‧‧electrode

518‧‧‧electrode

519‧‧‧Liquid

520‧‧‧Liquid

71‧‧‧ cylindrical recess

72‧‧‧Magnetic film

81‧‧‧micro coil

90‧‧‧ basal layer

91‧‧‧ computer layer in the display

92‧‧‧Insulation

93‧‧‧Magnetic film layer

94‧‧‧Micro coil array layer

95‧‧‧Priderized layer

96‧‧‧Separation layer

97‧‧‧Magnetic film layer

98‧‧‧Micro coil array layer

99‧‧‧Primary layer

900‧‧‧beam steering element array layer

901‧‧‧Face of the covering material

909‧‧‧ surface

910‧‧‧ device

911‧‧ points

100‧‧‧Lent Array or Microlens Array

101‧‧‧Color Filter Array

102‧‧‧Lighting elements

103‧‧‧Magnetic space light modulator

104‧‧‧Lighting device

105‧‧‧Full image generator

106‧‧‧ points

107‧‧‧ components

108‧‧‧ components

109‧‧‧Magnetic space light modulator

110‧‧‧Lighting device

111‧‧‧Color Filter Array

112‧‧‧Partialized components

113‧‧‧Magnetic space light modulator

114‧‧‧ points

115‧‧‧Compact hologram generator

116‧‧‧Positioning components

130‧‧‧Lighting device

131‧‧‧Color Filter Array

132‧‧‧Positioning components

133‧‧‧Magnetic space light modulator

134‧‧‧Magnetic space light modulator

135‧‧‧beam beam splitter element

136‧‧‧Complete hologram generator

137‧‧ points

171‧‧‧ Beam

172‧‧‧ Beam

159‧‧‧layers with components

1517‧‧‧electrode

1518‧‧‧electrode

1519‧‧‧Liquid

1520‧‧‧Liquid

Figure 1 is a schematic diagram of a holographic display device comprising a single magneto-optical spatial light modulator; Figure 2 is a schematic diagram of a holographic display device comprising a pair of components, each component comprising a single magneto-optical spatial light modulator; Figure 3 is a conventional use Schematic diagram of a portion of a pixel of a magneto-optical spatial light modulator; FIG. 4 is a schematic diagram of a conventional holographic display; FIG. 5 is a schematic diagram of three pixel cross-sections of one embodiment of a holographic display device including a pair of components, each of which The component comprises a single magneto-optical spatial light modulator; Figure 6A is a schematic diagram of the holographic display; Figure 6B is a schematic diagram suitable for achieving a compact holographic display; and Figure 7 is a schematic diagram of a manufacturing process for fabricating a micro-coil array. Figure 8 is a schematic diagram of a manufacturing process for manufacturing a micro-coil array; Figure 9 is a schematic diagram of a holographic display device; Figure 10 is a schematic diagram of a holographic display device, including two magneto-optical spatial light modulators for continuous encoding Amplitude and phase; Figure 11 is a schematic diagram of a holographic display device including a single magneto-optical spatial light modulator; Figure 12 is a specific embodiment of a holographic display Figure 13 is a schematic diagram of a holographic display device, comprising two magneto-optical spatial light modulators for continuously encoding amplitude and phase; Figure 14 is a diffraction simulation result obtained using MathCad (RTM); The fifth is the diffraction simulation result obtained by using MathCad (RTM); the figure 16 is the diffraction simulation result obtained by using MathCad (RTM); Figure 17 is a schematic view showing the arrangement of lens layers between two magneto-optical spatial light modulators; Figure 18 is a view of when light travels from a magneto-optical spatial light modulator to a second magneto-optical spatial light modulator FIG. 19 is a schematic diagram of an embodiment of a holographic display element; FIG. 20 is a schematic diagram of a beam steering element; FIG. 21 is a schematic diagram of a beam steering element; The schematic diagram of the display includes a light source 2201 in the form of a two-dimensional array of light sources, a lens 2202 in the form of a two-dimensional lens array, a spatial light modulator (SLM) 2203, and a beam splitter 2204. The beam splitter splits the light exiting the spatial light modulator into two beams, respectively illuminating a virtual observer window (VOWL) 2205 for the left eye and a virtual observer window (VOWR) 2206 for the right eye; Thirteen is a schematic diagram of the holographic display, comprising two light sources LS1, LS2 in the array of light sources, two lenses L1, L2, a spatial light modulator SLM and a beam splitter 2301 in the lens array. The beam splitter splits the light leaving the spatial light modulator into two beams, respectively illuminating the virtual observer window (VOWL) for the left eye and the virtual observer window (VOWR) for the right eye; It is a schematic cross-sectional view of the beam steering element.

90‧‧‧ basal layer

91‧‧‧ computer layer in the display

92‧‧‧Insulation

93‧‧‧Magnetic film layer

94‧‧‧Micro coil array layer

95‧‧‧Priderized layer

96‧‧‧Non-essential layers

97‧‧‧Magnetic film layer

98‧‧‧Micro coil array layer

99‧‧‧Primary layer

900‧‧‧beam steering element array layer

901‧‧‧Face of the covering material

909‧‧‧ surface

910‧‧‧Device structure

911‧‧ points

Claims (23)

A holographic display device comprising at least one magneto-optical spatial light modulator, wherein the holographic display device utilizes a Faraday effect to modulate light. The holographic display device of claim 1, comprising a first magneto-optical spatial light modulator and a second magneto-optical spatial light modulator, the first magneto-optical spatial light modulator An hologram is encoded with the second magneto-optical spatial light modulator, and the hologram display device produces a holographic reconstruction. The holographic display device of claim 2, wherein the first magneto-optical spatial light modulator and the second magneto-optical spatial light modulator are modulated in an independently controlled manner. The amplitude and phase of the pixel array. The holographic display device of claim 2 or 3, comprising a close combination of the first magneto-optical spatial light modulator and the second magneto-optical spatial light modulator, A compact method sequentially modulates the amplitude and phase of the light such that a complex value formed by an amplitude and a phase can be encoded in a transmitted light pixel by pixel. The holographic display device of claim 1, comprising a close combination of a magneto-optical spatial light modulator and a sufficiently homogenous compact light source, the combination being capable of being generated under appropriate illumination conditions. A three-dimensional image. The holographic display device according to claim 1, comprising a large-magnification three-dimensional image display device component, wherein the large-magnification three-dimensional image display device component comprises A close combination of a magneto-optical spatial light modulator or two magneto-optical spatial light modulators with holographic reconstruction of an object. A hologram display device as claimed in claim 1, which comprises a close combination of a magneto-optical spatial light modulator or two magneto-optical spatial light modulators and can also be used as a projector. The hologram display device of claim 1 or 2, wherein an hologram is encoded on the at least one magneto-optical spatial light modulator, and a hologram reconstruction is generated by the hologram display device . The hologram display device of claim 1, wherein the Faraday effect is achieved using a magnetic photonic crystal. The hologram display device of claim 1, wherein the Faraday effect is achieved using a doped glass fiber. The holographic display device of claim 1, wherein the Faraday effect is achieved using a magneto-optical film. The holographic display device of claim 8, wherein the holographic reconstruction is viewable via at least one virtual viewer window. The hologram display device of claim 12, wherein at least two virtual viewer windows are provided and can be laid using space or time multiplexing. The hologram display device of claim 8, wherein the hologram display The apparatus is operable to re-encode a hologram on the hologram carrier in time sequence for at least one viewer's left eye followed by the right eye. The hologram display device of claim 1, wherein the hologram display device has a beam steering element or a beam splitter. The hologram display device of claim 1, wherein the hologram display device has a computer (CIAD) layer in a display. The hologram display device of claim 1, wherein the hologram display device has an eye tracking function. The hologram display device of claim 1, wherein the hologram display device is illuminated with a backlight and a microlens array. The hologram display device of claim 1, wherein the device is a television. The holographic display device of claim 1, wherein the device is a screen. The hologram display device of claim 1, wherein the device is portable. A method of manufacturing a holographic display device, comprising: providing a glass substrate; and producing a magneto-optical space on the glass substrate by continuous printing or other means A plurality of layers of a light modulator. A method of producing a holographic reconstruction, comprising the steps of using a hologram display device according to any one of the above-mentioned claims.