Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
  • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
  • G02B26/10—Scanning systems
  • G02B26/101—Scanning systems with both horizontal and vertical deflecting means, e.g. raster or XY scanners
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B30/00—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images
  • G02B30/20—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images by providing first and second parallax images to an observer's left and right eyes
  • G02B30/22—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images by providing first and second parallax images to an observer's left and right eyes of the stereoscopic type
  • G02B30/25—Optical systems or apparatus for producing three-dimensional [3D] effects, e.g. stereoscopic images by providing first and second parallax images to an observer's left and right eyes of the stereoscopic type using polarisation techniques
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C9/00—Stereo-photographic or similar processes
  • G03C9/04—Vectographic-image
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
  • H04N13/30—Image reproducers
  • H04N13/324—Colour aspects
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
  • H04N13/30—Image reproducers
  • H04N13/332—Displays for viewing with the aid of special glasses or head-mounted displays [HMD]
  • H04N13/337—Displays for viewing with the aid of special glasses or head-mounted displays [HMD] using polarisation multiplexing
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
  • H04N13/30—Image reproducers
  • H04N13/398—Synchronisation thereof; Control thereof
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
  • H04N13/10—Processing, recording or transmission of stereoscopic or multi-view image signals
  • H04N13/189—Recording image signals; Reproducing recorded image signals
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
  • H04N13/10—Processing, recording or transmission of stereoscopic or multi-view image signals
  • H04N13/194—Transmission of image signals
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
  • H04N13/20—Image signal generators
  • H04N13/286—Image signal generators having separate monoscopic and stereoscopic modes
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
  • H04N13/30—Image reproducers
  • H04N13/332—Displays for viewing with the aid of special glasses or head-mounted displays [HMD]
  • H04N13/334—Displays for viewing with the aid of special glasses or head-mounted displays [HMD] using spectral multiplexing
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
  • H04N13/30—Image reproducers
  • H04N13/332—Displays for viewing with the aid of special glasses or head-mounted displays [HMD]
  • H04N13/341—Displays for viewing with the aid of special glasses or head-mounted displays [HMD] using temporal multiplexing
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
  • H04N13/30—Image reproducers
  • H04N13/363—Image reproducers using image projection screens

Definitions

• the invention relates to a method for generating a stereoscopic video image by means of light with partial images radiating different mutually orthogonal polarization states for the left and right eyes of a viewer who perceives the stereoscopic video tape through glasses with the respective polarization state of the light on a device for generating a stereoscopic video image by means of light with different, mutually orthogonal polarization partial images for the left and right eyes of an observer, for whom the stereoscopic video image can be perceived through glasses with two glasses that filter the respective state of light
• three-dimensional images are desirable for the future development of video technology.Not only is the greater entertainment value in television in the foreground, but three-dimensional images can also be a construction aid in computer-aided design, since the constructed element can be viewed directly and two-dimensional views with auxiliary lines for hidden edges can be avoided
• the three-dimensional images are depicted as flat sectional images in a plurality of planes lying one behind the other.
• the second takes advantage of the fact that a viewer only grips a three-dimensional image by looking at an object from different angles through his two eyes. Using this second one - • ? -
• stereoscopic two images captured from different angles are fed to the left or right eye, so that the viewer's brain, as in normal vision, perceives the objects shown on the images in three dimensions as usual.
• special balls are usually used, which filter the two images out of an overall image and feed them to the left or right eye of the viewer.
• the second method the generation of stereoscopic images, is also used in the method and the device as mentioned at the beginning.
• Two partial images are generated and superimposed with different polarization states that are orthogonal to one another. Glasses then filter out the partial image assigned to the left or right eye for each viewer via polarization filters.
• Such methods and devices are known from DE 39 10 420 A1, EP 0 328 357 A2, DE 36 07 629 C2, DE 32 01 837 A1 and DE 32 14 327 A1.
• picture tubes are used, as is common in television technology.
• polarization filters in front of a picture tube, the polarization of the image emitted by the light is either changed alternately, depending on the partial image shown, or the partial images generated on two picture tubes are projected on top of one another after filtering the image with different polarization.
• the viewers wear glasses with two polarization filters filtering out different polarization states, each of which allows one or the other partial image to pass through for each of the two eyes. If, for example, the two partial images are recorded at a defined distance with different cameras, the viewer obtains a plastic image.
• polarized light does not have to be used, since the partial images for the left and right eyes are generated alternating periodically, with the help of glasses the information for the left and right eyes being synchronized with the Representation of the corresponding drawing file is hidden.
• This technology would be suitable for lower energy losses compared to the prior art specified above. In practice, however, this assumption has proven to be incorrect. Due to the speed of the viewer's eye, the switching frequencies for opening and closing the apertures contained in the glasses must be very high. In order to avoid any annoying noises that may be expected from the mechanical mechanism of the aperture mechanism, only LCD matrices are suitable for use as panels. However, these only allow a small part of the light to pass through, so they also cause large energy losses.
• a further disadvantage of this technique is that a signal must be supplied to the aperture-controlled glasses in order to open the lens in front of the respective eye. Apart from bulky wiring of the glasses, only a remote control of the glasses remains, for example with infrared light. but which greatly increases the effort per pair of glasses.
• DE 31 40 404 A1 discloses a projection and recording device in which two images can be written onto different LCD arrays by a single laser beam using the two polarization states of the laser beam and can be projected on top of one another by light from other light sources.
• a controllable polarization device which, depending on the image to be written, transmits light from one or the other polarization device.
• the object of the invention is to provide a method for generating stereoscopic video images and to provide a corresponding device which allows stereoscopic video images to be generated with particularly little loss of energy with little effort.
• At least one light source is used to generate each partial image, which emits an intensity-controllable, essentially parallel, polarized light beam whose polarization state is equal to one of the two orthogonal polarization states or can be converted into it with little loss and which is scanned over a screen to generate at least one partial image.
• the invention thus uses differently polarized light for the two partial images, but makes use of the use of already polarized light sources, so that the energy loss is negligible.
• the display of the picture by TV picture tubes is dispensed with, as a result of the direct use of light for picture display instead of the conversion of electron beams to light on a screen, the energy losses resulting from such a conversion can also be avoided
• the method according to the invention can e.g. be carried out by generating two partial images for each eye separately on a screen via polarized light sources.
• a preferred development of the method according to the invention provides that the same at least one light source is used for both partial images, but the light beam is periodically switched to one or the other of the mutually orthogonal polarization states, so that only one light source is then used needed for both drawing files.
• the switching between the two mutually orthogonal polarization states with respect to the light propagation takes place after the light source and before rasterization.
• This allows the light beam to be rasterized, for example, via a single raster device for both partial images.
• This feature thus advantageously enables the method according to the invention to be carried out with particularly little effort, the energy losses also being lower because of the single raster device used for rastering.
• the device according to the invention for carrying out the method according to the invention is based on a device of the type mentioned at the outset and is characterized by at least one light source which emits an intensity-controllable, polarized, substantially parallel light beam and at least one raster device for deflecting the light beam onto a screen in terms of image and line to image at least one of the two drawing files.
• the device according to the invention is used to generate a video image via image points, the intensity of which is controlled by the light source, the rasterizing device causing the light beam to be rasterized on the screen in terms of image and line.
• the pixels are sequentially illuminated, as is customary in TV technology for a television tube, but the rasterization here takes place by deflecting a bundle of light.
• rotating polygon mirrors, swivel mirrors, but also acousto-optical modulators are known for such raster devices
• the at least one light source is a laser emitting a polarized light bundle, in particular a gas laser, a solid-state laser or a diode laser
• the outgoing light is polarized in commercially available lasers.
• the stimulated emission of the atoms of the laser medium excited by lasers leads to the coupling of the emitted light quanta in phase to the exciting light wave.
• a linear polarization which can be represented by two phase-coordinated left and right-circulating stimulating waves
• the left- or right-turning quanta in the laser medium are excited in phase and emitted so that all states are phase-corrected to linearly polarized light put together.
• the entire energy stored in the laser medium is brought together in a single bundle of defined energy, so that energy losses due to quanta with undesired polarization are negligible.
• the entire energy available at the laser frequency in the laser medium is thus combined in a light bundle with a very high degree of polarization.
• the laser also offers the advantage of very good parallelism of the generated light bundle compared to other light sources. This enables a sharp image of the
• Pixels of the video image without the need for additional parallelizing optics and apertures that reduce intensity. This not only simplifies the construction, it also avoids energy losses on the panels.
• gas lasers have proven to be suitable which, with a simple structure, already provide degrees of polarization on the order of 100: 1.
• Such gas lasers are used to generate video images in continuous wave and through additional modulators controlled in terms of intensity.
• Technically usable modulators also control the intensity via polarization. This further increases the degree of polarization.
• light beams with a degree of polarization of 10 4 1 were achieved behind the modulators. This high polarization is by far sufficient for the stereoscopic display of video images.
• both polarization states are circularly or linearly polarized with respect to one another or whether other elliptical states are used.
• the light source emits linearly polarized light. If it is a laser, the complete emission of the photons of all states of the laser medium in the linear polarization state results in an excellent use of energy.
• Linear polarization offers other advantages energetically. Since, for example, the intensities of three light sources are mixed in color television, an optical system that contains mirrors, for example, is required to bring the colored light bundles together. Reflections can, however, depend on the polarization of light, according to Brewster's law, so that in the case of elliptical polarization, a loss of intensity must generally be expected.
• the linear polarization is characterized by the fact that the mirrors can be arranged so that losses due to incomplete reflection only occur insignificantly.
• the light beam that is linearly polarized on the input side does not necessarily require a linear polarization effect for the spectacle lenses, since known optical components such as Fresne's parallelepiped can be used to transform linearly polarized light into circularly polarized or elliptically polarized light by means of phase shifting of a polarization component even without significant intensity losses.
• known optical components such as Fresne's parallelepiped can be used to transform linearly polarized light into circularly polarized or elliptically polarized light by means of phase shifting of a polarization component even without significant intensity losses.
• the same light sources and the same raster device are used to generate the two partial images.
• a polarization changing device is provided in the beam path of the light beam, with which the polarization of the light beam can be switched in one or the other of the orthogonal polarization states. This will create a A further reduction in effort is achieved since the number of light sources and the raster devices is halved compared to a device which generates the two partial images using different light sources and raster devices
• the polarization change device could be arranged at any point through which the beam of rays passes
• the polarization change device between the light source and the scanning device is thus arranged in front of the screening device and not behind it, that is to say at a location at which the bundle of light still has a very small extent compared to a possible arrangement behind the screening device the advantage that further optics for focusing into the polarization device and for compensating for a possible beam expansion behind the polarization change device can be dispensed with
• the necessary width of the polarization change device is still very small at this location, where the light beam has not yet been expanded by the raster device. If, for example, the kerf effect or the Pockels effect is used to rotate the polarization change, only a small amount is required for the polarization change Voltages to achieve a suitable field strength For this development, the circuitry required to apply the respective state of polarization is also low
• the light source is designed to generate linearly polarized light and the polarization change device is a Pockels cell, in which the plane of polarization of the light passing through is rotated when an electrical voltage is applied.
• the polarization change device is a Pockels cell, in which the plane of polarization of the light passing through is rotated when an electrical voltage is applied.
• the device has a plurality of light sources with different wavelengths and there are a plurality of polarization devices, one for each light for each wavelength.
• Colored stereoscopic video images can thus also be generated in a simple manner by having a separate one for each wavelength Pola ⁇ satio ⁇ sa mecanicsein ⁇ chtung is provided, the use of extremely wavelength-dependent Pola ⁇ sationsa mecanicseifferept is possible
• the light emerging from the polarization change devices is combined with the aid of a device to form a common bundle of light, which in turn is imaged on the screen by the raster device.
• D e r means for combining the different light bundles to form a common light bundle may for example be a mirror system.
• Fig. 1 shows an embodiment of an inventive device for generating stereoscopic video images
• Fig. 2 shows an arrangement of light sources and polarizers for another embodiment of a device according to the invention.
• a primary light bundle 10 is generated for imaging with the aid of a light source 12, which is a gas laser that is operated in a continuous wave. This gas laser emits linearly polarized light.
• a polarizer 14 is used, as it is e.g. is available under the type designation EOM 3079 from Dipl. Ing. Eckhardt Dschreiber, Ettlinger Straße 5, 751 6 Karlsbad.
• This polarizer 14 works with the help of the Pockels effect.
• a voltage is applied, the linear polarization plane of the primary light bundle 10 emanating from the light source 1 2 is rotated.
• a polarization filter which only allows a linear polarization plane to pass through is arranged at the output of the polarizer 14. The result of this is that this polarizer is a function of the voltage applied to the polarizer 14 leaving light bundle 1 6 is applied with different intensity and can be modulated
• a rotating mirror 20 and a swivel mirror 22, with which the light bundle 1 6 is deflected in a horizontal and vertical direction onto a screen 24, are further arranged. This creates a video image on the screen 24 in a known manner Direction of the drawn arrows viewer is detectable
• a Fresnel lens 26 and an optic 28 are provided which serve to expand the beam rastered via the mirrors 20 and 22 for a larger screen area of the screen 24 and to deflect the light impinging at large angles to the Fresnell ⁇ ns ⁇ > 26 again towards the viewer for him the screen 24 is illuminated uniformly
• a stereo image can be generated if for the left and the right eye of the viewer different stereoscopically recorded partial images are displayed with light from two orthogonal polarization states.
• the two partial images for the left and right eye are separated with the aid of glasses 30, in which the left and right eye glasses only allow one of the two orthogonal polarization states to pass through
• the light bundle 1 6 is already polarized.Therefore, with two such raster devices and two light sources 1 2, two partial images with two polarization alignments adapted to the glasses of the glasses 30 could be generated, so that a viewer through these glasses 30 sees a stereoscopic video image
• a less complex route was covered.
• the same light source 12 with modulator 14 and the raster device consisting of rotating mirror 20 and pivoting mirror 22 were used for both partial images, and the polarization of the light beam 16 incident on the raster device was periodically switched.
• the light bundle was modulated depending on the polarization of the light beam 1 6, depending on whether the partial image for the left or the right eye is to be generated on the screen 24
• a polarization change device 34 is provided. This consists of the same Pockels cell as is used for the modulator 14, but without the polarization filter at the output of the modulator in the case of the polarization change device 34.
• the polarization change device 34 Due to the Pockel effect, the polarization change device 34 only rotates the polarization of the incident linearly polarized light beam. To change the polarization quickly with respect to the first and second partial image, the polarization change device 34 is acted upon by a control device 36 with square waves, so that the polarization for half of a period of the square wave the first field and during the other half the polarization for the second field is transmitted. For this purpose, the light bundle 16 is modulated in synchronism with the rectangular wave with respect to the first and second partial images.
• the described embodiment is betneb.n with a single, designed as a laser light source 1 2, which does not allow a colored representation.
• the simplest way to do this is to replace the light source 12 by three light sources of different wavelengths, the light beams being combined, for example with mirrors, as known from the prior art, to form a common parallel light bundle.
• the polarization change generated is wavelength-dependent.
• a beam guide for three light sources 40, 42, 44, for which lasers are used, which is particularly favorable in terms of expenditure, is explained below with reference to FIG. 2.
• the light bundles 46, 48, 50 generated are again fed to modulators 52, 54, 56 for intensity control.
• Each modulated bundle of light is then passed through a polarization changing device 58, 60, 6i.
• the polarization for generating the stereoscopic partial images is controlled in the same way and the light intensity with respect to the first and second partial images is controlled synchronously, as has already been described above with regard to the polarization changing device 34.
• the light bundles After passing through the polarization change devices 58, 60, 62, the light bundles are combined by a mirror system consisting of mirrors 64, 66 and 68 to form the common light bundle 1 6, which, as illustrated with reference to FIG. 1, is shown as a video image on the screen 24
• Dichroic mirrors can be used for mirrors 64, 66 and 68, but when designing them it should be noted that in general the reflection and transmission behavior is dependent on the polarization.
• so-called dielectric mirrors which are thin due to interference are also suitable Layers of reflected or transmitted partial beams can be designed to be totally reflective or totally transmissive for certain wavelengths. The dimensioning of these layers and the selection of layer materials are known to the optician, in particular through the use of such layers in the coating of lenses
• the exemplary embodiments described show a simple video system for stereoscopic video images, which is also particularly suitable for stereoscopic large-scale projection if the distance between the screen 24 and the raster device is chosen to be sufficiently large and / or the optics 28 are designed accordingly.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Optics & Photonics (AREA)
• Testing, Inspecting, Measuring Of Stereoscopic Televisions And Televisions (AREA)
• Stereoscopic And Panoramic Photography (AREA)
• Devices For Indicating Variable Information By Combining Individual Elements (AREA)

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• 1995
  • 1995-10-06 DE DE19537356A patent/DE19537356C1/de not_active Expired - Fee Related
• 1996
  • 1996-08-23 WO PCT/EP1996/003732 patent/WO1997014074A1/de not_active Ceased
  • 1996-08-23 US US08/836,241 patent/US5903304A/en not_active Expired - Fee Related
  • 1996-08-23 EP EP96929317A patent/EP0796453A1/de not_active Withdrawn
  • 1996-08-23 JP JP9514662A patent/JPH10510637A/ja active Pending
  • 1996-09-17 TW TW085111445A patent/TW317687B/zh active

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