Abstract: A Fresnel lens sheet comprises a Fresnel lens on one surface thereof, wherein respective unit surfaces constructing the Fresnel lens sheet have rough surfaces. Since it has a rough surface, it enables suppressing the occurrence of moire, when making up a screen. The other Fresnel lens sheet comprises a Fresnel lens on one surface thereof, and a fly-eye lens or prisms as a regular concavities and convexities configuration for suppressing regular reflection on the surface thereof on a side opposite to the side having the Fresnel lens formed thereon. Since it has on its rear surface a fly-eye lens or a prism, it enables suppressing the occurrence of ghost image.

Abstract: A rear projection screen without ghost image artifacts, which can reflect light containing images to a display screen and effectively eliminate ghost image artifacts. The invention includes a reflective mirror, a field lens, a diffusive plate, and a diffuser located at the field lens facing the reflective mirror. Through the diffusion effect of the diffuser and minimizing the thickness of the field lens, ghost image artifacts can be effectively reduced.

Abstract: A Fresnel lens sheet of the present invention is applicable to a transmission-type projection screen, which comprises a layered structure provided with at least a base material layer, a lens layer formed into a Fresnel lens configuration, an incident surface on which projection light is incident and an light-emission surface from which the projection light is emitted, wherein a total reflection surface is disposed in the layered structure at a position between the incident surface and the light-emission surface, the total reflection surface totally reflecting a portion of projection light proceeding on an optical path in a direction from the lens layer side toward the base material layer side.

Abstract: Methods of manufacturing lenses used in projection television display device screens. A method includes pressing at least one resin bearing surface of a film over a die mold pattern formed in an outer surface of one or more lens shaping rollers, and curing the resin bearing surfaces to form patterns on the surfaces of the film. The lens shaping rollers are made by forming a patterned planar surface into a cylinder that has a first set of patterns formed in an interior portion of the cylinder, inserting a die mold in the interior portion of the cylinder over the first set of patterns to form a second set of patterns, and separating the die mold from the cylinder to expose the second set of patterns in an outer portion of the die mold. The manufacturing methods produce strong and lightweight screens that are safe and easy to handle.

Abstract: A screen assembly that combines an angle re-distributing prescreen with a conventional diffusion screen. The prescreen minimizes or eliminates the sensitivity of the screen assembly to projector location. The diffusion screen provides other desirable screen characteristics. Compatible screen structures, along with methods for fabricating high resolution prescreens and methods and devices for maintaining the desired relationship between the prescreen and the diffusion screen are contemplated.

Abstract: A screen for a projection display system. The screen has a Fresnel lens for converting incoming light into parallel light and a Lenticular lens disposed on a surface of the Fresnel lens to change a path of the parallel light from the Fresnel lens, providing a three-dimensional image to a user. The Lenticular lens includes plural pixel lenses corresponding to pixels of the screen. Each of the pixel lenses has a central diffusing portion formed on a light-outgoing portion and a peripheral diffusing portion formed on a peripheral portion of the central diffusing portion.

Abstract: An East-West switching transistor is coupled between a flyback transformer primary winding and a horizontal deflection output transistor circuit to control retrace energy to obtain an East-West modulation of the deflection current amplitude as required for East-West pincushion raster correction. A pair of series coupled first and second capacitors forming a capacitive voltage divider are coupled to a retrace resonant circuit that includes the deflection winding via a sampling switch, during a first half of a retrace interval, to produce a first ramping capacitor voltage in the first capacitor from a portion of a retrace pulse voltage. The first capacitor is coupled to an East-West pincushion raster correction current for producing a second ramping capacitor voltage in the first capacitor that ramps in an opposite direction. A comparator is responsive to the capacitor voltage for controlling a conduction interval of the East-West switching transistor.

Abstract: A display system has a directional reflection screen with a triangularly-shaped mirror sheet as horizontal focusing for observers and stereoscopic image projecting means. The directional reflection screen has a triangularly-shaped mirror sheet with included angles at least some of which are non-right angles. This enables a plurality of observers to simultaneously obtain a stereoscopic view using a binocular parallax without wearing special glasses and without having to position themselves in a very limited number of positions relative to the screen. Vertical diffusion can also be provided by using a lens sheet. The screen can be made concave in the horizontal or vertical directions, or both.

Abstract: For providing a rear-projection type display apparatus, and a translucent type sheet for use therein, in particular, using an image modulation element, such as, a liquid crystal or a DMD (Digital Micro-mirror Device), etc.

Abstract: A display system has a directional reflection screen with a triangularly-shaped mirror sheet as horizontal focusing for observers and stereoscopic image projecting means. The directional reflection screen has a triangularly-shaped mirror sheet with included angles at least some of which are non-right angles. This enables a plurality of observers to simultaneously obtain a stereoscopic view using a binocular parallax without wearing special glasses and without having to position themselves in a very limited number of positions relative to the screen. Vertical diffusion can also be provided by using a lens sheet. The screen can be made concave in the horizontal or vertical directions, or both.

Abstract: A lenticular lens sheet that is bonded to a front faceplate and used in a rear projection type screen is disclosed. The lenticular lens sheet has a plurality of lenticular lenses arranged on one surface of a light-transmitting substrate, and projecting non-convergence parts arranged on the other surface of the light-transmitting substrate in positions different to positions of convergence of light from the lenticular lenses. An external light absorbing layer that absorbs external light is provided on a summit portion of each of the projecting non-convergence parts. Also, the lenticular lens sheet and the front faceplate are bonded together at the summit portions of the projecting non-convergence parts using an adhesive, and the width of adhesive layers formed through curing of the adhesive is less than the width of the external light absorbing layers. Consequently, the adverse effects caused by blockage of light are prevented.

Abstract: A rear-projection screen 3, including at least a lenticular lens sheet 32 and a Fresnel lens sheet 31, is configured so that the lenticular lens sheet 32 contains, in a base material thereof made of a resin, light diffusing microparticles made of a resin having a refractive index different from a refractive index of the base material, and the light diffusing microparticles satisfy 0.5 &mgr;m≦&Dgr;N1×d1≦0.9 &mgr;m, where &Dgr;N1 represents a difference between a refractive index of the light diffusing microparticles and a refractive index of the base material of the lenticular lens sheet, and d1 represents an average particle diameter of the light diffusing microparticles. With this, a rear-projection screen with small wavelength dependency of diffusion characteristics can be provided utilizing only resins with general properties.

Abstract: Provided is a Fresnel lens sheet having the advantage of reducing unnecessary rays of light that may go out around the center area of the concentrically-configured Fresnel lens of the sheet. When it is combined with a lenticular lens sheet to construct a viewing screen, the screen has the advantage of preventing white spots from appearing around its center area. The Fresnel lens sheet is for screens for rear projection image displays, and is characterized in that the lens pitch in the center area of the concentrically-configured Fresnel lens of the sheet differs from that in the peripheral area thereof, and that the lens pitch in the center area is larger than that in the peripheral area.

Abstract: The present invention is a screen, such as is used in back-lit projection screens, having a Fresnel lens laminated to another layer for support. The screen includes a Fresnel lens having an output surface, and a dispersing screen supportingly attached on a first side to the output surface of the Fresnel lens.

Abstract: A rear projection screen of the present invention includes lens sheets or optical sheets having an optical function of condensing or diffusing light. The lens sheets or optical sheets have, as a whole, two or more diffusing layers (diffusing parts) separately provided in the light-transmitting direction. It is preferable that one of the two or more diffusing layers be provided on the light-entering-side surface of the outermost lens sheet or optical sheet on the light source side and that another one of the diffusing layers be provided on the light-emerging-side surface of the outermost lens sheet or optical sheet on the observation side. Any two of the two or more diffusing layers are such that the light-source-side diffusing layer has a diffusing power lower than that of the observation-side diffusing layer.

Abstract: A display device including liquid crystal display panels, arrays of convergently transmissive elements for forming an erect and real image, and fresnel lenses for magnifying the image. The configured surface of the fresnel lens is arranged on the light incident side. The configured surface includes periodic ridges with flat crests and inclined surfaces. Shading layers are provided on the flat crests to eliminate ghosts.

Abstract: A rear projection type screen is provided with a Fresnel lens and a lenticular lens, for use with a light valve having pixels. The rear projection type screen has such lens pitches that the secondary moiré pitch PMM indicated by the following equation is 3 mm or less, taking the lens pitch of the Fresnel lens as PF (mm), the lens pitch of the lenticular lens as PL (mm), and the pitch of the pixels in the light valve as PS (mm).

Abstract: Provided is a plastic sheet for rear projection screens, which has a two or more multi-layered structure and which can be readily warped without being unfavorably swollen or waved. The plastic sheet is constructed to have a two or more multi-layered structure, in which the coefficient of linear expansion (at 20° C.) of one layer is higher by at least 1.0×10−6 mm/(mm·°C.) than that of any other layer. In one embodiment of the plastic sheet, the layer of which the coefficient of linear expansion is higher than that of any other layer contains a fine particulate rubber material having a diameter of from 0.1 to 100 &mgr;m to such a degree that the rubber material content thereof is higher by at least 0.5% by weight than that of any other layer.

Abstract: A novel system and method for viewing optical images with enhanced apparent depth is disclosed. The present invention utilizes the combined effects of a polarizing layer and a magnifying layer to achieve the enhanced apparent depth of the images being viewed. In a preferred embodiment, a polarizing layer is used in combination with a Fresnel layer having concentric circles to enhance the apparent depth of the images being viewed.

Abstract: A micro-lens array sheet having a wide field angle, a field angle control, a high light efficiency, a high brightness and a high contrast, which is provided with a layer of micro-lenses each shaped to be a centro-symmetry convex or concave micro-lens. A layer of either a light diffusion sheet or a sheet filled with light diffusive agent is attached on a light transmitting side of the micro-lens array sheet. The micro-lenses are aligned in a diamond grid array or an array including a combination of diamond-shape and hexagonal-shape micro-lens blocks.

Abstract: To provide a rear-projection type screen in which, without the need for a tape-attachment operation on the outer circumferential part of the lens sheets, the top of the Fresnel lens can be prevented from being pared by the abrasion caused by the vibration during transportation. A rear-projection type screen according to the present invention is configured from two or more overlapping sheet-like members such as a Lenticular lens sheet 1 and Fresnel lens sheet 2, in which a fixing protrusion 3 is integrally formed in the sheet-like members in such way that neither of the two sheet-like members is displaced from the state in which the two sheet-like members overlap. A protrusion, used to attach the rear-projection type screen to the main body of a rear-projection-type image display apparatus or the screen frame, may be integrally formed in the sheet-like members from which the rear-projection type screen is configured.

Abstract: A liquid crystal rear-projection TV screen has a double-side lens sheet and horizontal lenticular sheet. A vertical lenticular portion is disposed on the rear side of the double-side lens sheet, and Fresnel lens is disposed on the front side. A horizontal lenticular portion is disposed on the rear side of the horizontal lenticular sheet, and a light-shielding layer and protective resin substrate are disposed on the front side. The resin substrate of the double-side lens sheet has a low transmittance, and the resin substrates of the horizontal lenticular sheet have high transmittances. The observer recognizes an image on the double-side lens sheet arranged behind the light-shielding layer.

Abstract: Moire fringes are effectively solved in rear projection screens including a combination of a Fresnel lens sheet and a lenticular lens sheet both having fine lens pitches. In a rear projection screen including a Fresnel lens sheet having a lens pitch of at most 0.12 mm and a lenticular lens sheet having a lens pitch of at most 0.6 mm, the pitch, PM (mm), of the moire fringes that may be given by the Fresnel lenses and the lenticular lenses at a spatial frequency of at least 3/P1 is at most 3 mm, the moire pitch, PM (mm), being given by formula (1), PM=1/|n/P1−m/P2| (wherein P1 (mm) indicates the smaller one of the Fresnel lens pitch and the lenticular lens pitch, P2 (mm) indicates the other one thereof, and n and m each are a natural number satisfying the formula (2), n≦15×P1/P2, and formula (3), m≦15×P2/P1).

Abstract: A rear projection screen including a Fresnel lens sheet arranged on the projection side, and a lenticular lens sheet arranged on the observation side. The Fresnel lens sheet has a lenticular lens for vertical diffusion on its light-entering side. The lenticular lens for vertical diffusion containing a plurality of convex lenses that extend horizontally, and these plural convex lenses are arranged with a constant pitch. Further, the diffusion angle of the lenticular lens for vertical diffusion continuously increases, and, at the same time, the direction of diffusion is gradually inclined to the central part as the distance from the central part toward each of the edges on the screen surface increases. The diffusion properties (the angle and direction of diffusion) of the lenticular lens thus continuously vary between the central part and the edges of the screen surface.

Abstract: A projector screen is composed of a Fresnel lens for collimating incident light from a light projection device, a lenticular lens formed of a plurality of constituent lenses for forming and spreading an image from the parallel light, and a screen protection panel for protecting a screen set up adjacent to the lenticular lens. A projecting part of a predetermined height is formed on the rear side of the screen panel facing the lenticular lens, and on the tip of the projecting part a black stripe is formed to serve as a light-absorbing means. The height of the projecting part is lower than that of a convex surface of the lenticular lens. The widened range of light-spreading angle of the lenticular lens improves a horizontal viewing angle.

Abstract: A rear projection screen of the present invention includes lens sheets or optical sheets having an optical function of condensing or diffusing light. The lens sheets or optical sheets have, as a whole, two or more diffusing layers (diffusing parts) separately provided in the light-transmitting direction. It is preferable that one of the two or more diffusing layers be provided on the light-entering-side surface of the outermost lens sheet or optical sheet on the light source side and that another one of the diffusing layers be provided on the light-emerging-side surface of the outermost lens sheet or optical sheet on the observation side. Any two of the two or more diffusing layers are such that the light-source-side diffusing layer has a diffusing power lower than that of the observation-side diffusing layer.

Abstract: A rear projection display apparatus is provided with a screen unit. The screen unit includes a Fresnel lens sheet for gathering incident image light, a lenticular lens sheet for causing the image light gathered by the Fresnel lens sheet to be incident thereon and to be diffused, and having an external-light absorbing layer on the emergent side thereof, and a light diffusing structure for diffusing the image light incident on the lenticular lens sheet. The haze of the light diffusing structure is set at a predetermined value, and the covering ratio per unit area of the external-light absorbing layer is set according to the diffusion property represented by the haze so that it is smaller than the case in which no light diffusing structure is employed.

Abstract: The present invention provides a projection screen in which both primary and secondary moiré patterns never become conspicuous even when the pitch of lenticular lenses is made fine. When the pitch of the concentric circular grooves on the Fresnel lens face 2 of a tranparent base 1 is indicated by pF, the repeating pitch of the cylindrical lens faces on the lenticular lens face 3 is indicated by pL, the pitch of the elliptical moiré is indicated by pE, the pitch of the hyperbolic moiré is indicated by pH, and when pE and pH are defined as follows: in the case where pL>pF, pE=1.0/(1.0/pF−[pL/pF]/pL) pH=1.0/(1.0/pL−1.0/pF+[pL/pF]/pL), and in the case where pF>pL, pH=1.0/(1.0/pL−[pF/pL]/pF) pE=1.0/(1.0/pF−1.0/pL+[pF/pL]/pF) ([X]: the integer part of X), the relationship pE/pH≧2.4 or pH/pE≧2.4 is fulfilled. Further, the relationship MAX(pH, pE)<1.

Abstract: A dispersing element for a rear projection screen assembly is sensitive to the polarization of the light passing through the element. In particular, the element disperses light having a first polarization differently from light having a second polarization orthogonal to the first polarization. The dispersing element may be aligned with a polarization axis neither parallel nor perpendicular to the polarization of the light passing through the element. The dispersing element may also be employed with a polarizer to remove unwanted light that propagates through the dispersing element. The dispersing element may also be rotatably mounted relative to a polarized light source so as to vary the angle between the polarization axis of the element and the polarization direction of the light.

Abstract: The invention relates to a device for picture recording that is used in image sensors in robotics, navigation and surveillance systems. Said device comprises a lighting device having several series connected lasers as a light source and a dispersing lens as well as an optical element with which high luminance laser light is emitted while complying with safety regulations.

Abstract: A display device including liquid crystal display panels, arrays of convergently transmissive elements for forming an erect and real image, and fresnel lenses for magnifying the image. The configured surface of the fresnel lens is arranged on the light incident side. The configured surface includes periodic ridges with flat crests and inclined surfaces. Shading layers are provided on the flat crests to eliminate ghosts.

Abstract: In a screen for a rear image projection system, a Fresnel lens sheet, a lenticular lens array sheet whose longitudinal direction is arranged in the vertical direction, and a light diffusion sheet are provided in that order from the projection side. The light diffusion sheet has louver-shaped light absorption wall columns whose longitudinal direction is arranged in the horizontal direction and a light diffusion layer. The light diffusion layer is located on the observation side of the light absorption wall columns. Projected light is properly dispersed and exits without causing the absorption loss due to the light absorption wall columns. Outside light entering from the observation side is diffused in the light diffusion layer and absorbed by the light absorption wall columns. Also, the total reflection component on the lenticular lens surface is absorbed by the light absorption wall columns. As a result, the decrease of contrast caused by the diffuse reflection can be reduced greatly.

Abstract: A lenticular lens sheet 10A comprises, on the light-entering surface thereof, a light-entering lens part in which a plurality of light-entering lenses 11 are formed, and, on the light-emerging surface, a light-emerging lens part in which a plurality of light-emerging lenses 12 are formed. The light-emerging lenses 12 are so arranged that they respectively correspond to the condensing positions of the light-entering lenses 11. Further, a protruded portion 13A having a substantially rectangular cross section is formed on the light-emerging surface, at a position corresponding to the non-condensing position of each one of the light-entering lenses 11, and a black stripe 14 is formed on the top face 13a of this protruded portion 13A by the application of a light-absorbing agent. The light-entering lens 11 is in the shape of a convex lens projecting toward the light-entering side, and so designed that its condensing point will be inside the lenticular lens sheet 10A.

Abstract: A rear projection screen (1) comprising a lenticular structure (5) and a Fresnel structure (4). The Fresnel structure (4) has riser edges (9) and Fresnel facets (7). The Fresnel facets (7) are divided into two parts. The first part (11) encloses an angle .psi. with the plane of the projection screen. The second part (13) is substantially parallel to the plane of the screen. The Fresnel structure (4) and the lenticular structure (5) are fixed to each other at the second parts of the Fresnel structure.

Abstract: A screen for a projection-type video display apparatus. A linear-type Fresnel lens has a lens pattern on a first side for receiving light energy from a light source. A second side of the Fresnel lens is opposite the first side. The light energy exits the Fresnel lens from the second side. A hologram is affixed to the second side of the Fresnel lens for managing the dispersion of the light energy exiting from the second side of the Fresnel lens. The hologram is affixed to the Fresnel lens by any of various lamination processes.

Abstract: A rear projection type image display device includes a single projection lens, a Fresnel lens sheet, and a lenticular lens sheet 4 having black stripes in an area where when the light entered through the Fresnel lens sheet is transmitted, the outgoing light does not pass. When the angle (deg) of incidence to the lenticular lens sheet 4 is taken to be .theta., the total light transmittance (%) of the lenticular lens sheet to the light with the angle .theta. of incidence is taken to be Tt(.theta.), and the light transmittance loss by a light absorbent contained in the lenticular lens sheet is taken to be .alpha., as shown by (b), (c) in FIG. 4, in the central part of the lenticular lens sheet, if .vertline..theta..vertline.=5, the expression Tt(.theta.)>70.times.(1-.alpha.) is satisfied, and if .vertline..theta..vertline.=20, the expression Tt(.theta.)<50.times.(1-.alpha.) is satisfied.

Abstract: A transmission screen including a lenticular lens sheet having glass beads, having lenticular lenses, and a Fresnel lens sheet. Light is projected on the transmission screen by a projector, and an image made up of a large number of picture elements is thus projected onto the lenticular lens sheet. When the picture element pitch of the picture elements is designated by P, the arrangement pitch r of the lenticular lenses of the lenticular lens sheet is designated by r, and the particle diameter of the glass beads is designated by d, these P, r and d fulfill the following conditions: r/P.ltoreq.1/4.0 and 1.0 .mu.m.ltoreq.d.

Abstract: A rear projection screen free from lowering of resolution which is caused when the screen set undergoes separation or undesirably warps due to a change in the external humidity. The rear projection screen is composed of a plurality of sheets, a front surface sheet 13, a lenticular lens sheet 11 and a Fresnel lens sheet 12. The front surface sheet 13 and the Fresnel lens sheet 12 are respectively composed of two layers, an inner layer 13a, 12a and an outer layer 13b, 12b. The inner layer 13a, 12a is made from a material having susceptibility to water higher than that of a material from which the outer layer 13b, 12b is made.

Abstract: A projector screen is provided with a Fresnel lens for collimating lights projected from a projection lens provided in a projection device. A lenticular lens having a plurality of pillar lens elements successively arranged in parallel forms an image from the collimated lights projected by the Fresnel lens and spreads the image. A protection panel is installed on the front surface of the lenticular lens for protecting the lenticular lens. Also, a plurality of parallel spreading units is formed along the central axis of each lens element at the contact portion of the lenticular lens and the protection panel for providing a wide viewing angle of the image. The surface of the lenticular lens opposing the protection panel is flat so as to adhere to the protection panel.

Abstract: A free space imaging system utilizing a doublet form of optic. The doublet is configured with two large Fresnel lenses configured such that their echelon groove components are mutually oppositely disposed within the optical path of the system. The method includes an arrangement wherein the output focal plane deliberately is curved and generated with a relatively wide field of view to evoke an emulation of three-dimensionality.

Abstract: A Fresnel lens sheet of a multifocal type is intended to be used in combination with a lenticular lens sheet to construct a rear projection screen for a rear projection television receiver. An annular portion (2) of the Fresnel lens sheet at a distance (R) in a range of 0.05 h to 0.5 h, where h is the height of the Fresnel lens sheet, from the optical center (C) of the Fresnel lens sheet, have the shortest focal length f.sub.min among those of other portions of the Fresnel lens sheet, whereby uniformity in brightness of a screen employing the Fresnel lens sheet can be achieved. Alternatively, a portion where an exit angle (.theta.) of outgoing light ray relative to a normal to the surface of the Fresnel lens sheet is the greatest, lies at a distance (R) in a range of 0.3 h to 0.8 h from the optical center (C) of the Fresnel lens sheet, to obtain the same result.

Abstract: A Fresnel lens sheet (11) used in combination with a lenticular lens sheet (12) to form a rear projection screen of a TV set, has Fresnel lens elements (15) on a front surface thereof. The Fresnel lens elements (15) include a first group of Fresnel lens elements (15a) and a second group of Fresnel lens elements (15b). The first group of lens elements (15a) has a first focal length (f.sub.1) which is greater than a second focal length (f.sub.2) of the second group of lens elements (15b). The first group lens elements (15a) and the second group of lens elements (15b) are disposed alternately. The above configuration provides an increased vertical angular range of a viewing region from which pictures displayed on the rear projection screen can be viewed satisfactorily, as well as an increased luminance of the rear projection screen.

Abstract: A single plate (3) is provided with a first lens structure (7) of longitudinal lenses (9) on one side. A pattern of strips (15) of a light-absorbing material is provided on the other side. The strips (15) extend parallel to the longitudinal lenses (9) in the horizontal direction when the screen is in use. The screen includes a second lens structure (19) and a diffuser on the side with the strip pattern. This vertical lens structure (19) ensures the spread of light in the horizontal direction, while the diffuser ensures the spread of light in the vertical and horizontal directions. The lenses (21) of the second lens structure (19) have a very much larger power than those of the first, horizontal lens structure (7).

Abstract: A transmission type projection screen comprises a plurality of sheets. The front sheet nearest to the front observation side is an ambient light attenuating front sheet which is provided on its surface facing the rear side with first prism lenses formed by successively and horizontally arranging unit triangular prisms. Each unit triangular prism has a sharply inclined surface inclined at an angle of about 90.degree. to the surface of the front sheet, and a gently inclined surface inclined at an angle in the range of 5.degree. to 40.degree. to the surface of the front sheet. The first prism lenses are disposed with the gently inclined surfaces of the unit triangular prisms thereof facing upward. Second prism lenses may be provided on its surface facing the front observation side, each of the second prism lenses also having a sharply inclined surface and a gently inclined surface.

Abstract: An optical instrument is described in which a diffractive element (25) is located at a focal or image plane (3) of the instrument and the diffractive element (25) is effective to produce an array (6) of a plurality of exit pupils at a viewing position for the instrument and thereby to form an enlarged exit pupil for the instrument.

Abstract: In a device with a laser for image presentation in which the laser emits laser light of a defined coherence length L at a given wavelength .lambda. and in which there is arranged in the path of the laser light a first structure with which phase displacements can be carried out for individual photons of the laser light in accordance with a predetermined distribution, it is provided that the average path given by the ratio of the average root mean square of the phase displacement formed by the distribution and the magnitude of the wave vector k=2.pi./.lambda. of the laser is greater than the coherence length L multiplied by a factor of 1/(12).sup.1/2.

Abstract: A holographic screen of a rear projection type for use in a projector for transmitting projection light received from a rear end of the projector onto a viewing surface. The holographic screen includes a holographic sheet including a viewing surface for forming the received projection light into an image viewing, a plurality of diffusion protrusions disposed on the viewing surface in predetermined intervals along horizontal and vertical directions of the viewing surface for diffusing incident projection light, and a plurality of scattering protrusions formed over the entire viewing surface for scattering the received projection light, and a plurality of light absorbers formed between the plurality of protrusions, for absorbing ambient light incident to the viewing surface. Thus, an image with improved contrast is displayed on a viewing surface of the holographic screen.

Abstract: An active energy ray-curable composition comprising(A) 20 to 80 parts by weight of a compound represented by the following general formula I: ##STR1## wherein R.sup.1 represents hydrogen or methyl, X and Y may be the same or different and represent methyl, chlorine, bromine or iodine, and t and u each independently represent an integer of 0-2,(B) 20 to 80 parts by weight of at least one compound having at least one acryloyl or methacryloyl group in the molecule, or (B-1) 10 to 90 parts by weight of at least one compound having at least two acryloyl or methacryloyl groups in the molecule and (B-2) 1 to 90 parts by weight of at least one monoacrylate or monomethacrylate compound having one acryloyl or methacryloyl group in the molecule, and(C) 0.

Abstract: A permeable screen possesses superior brightness, high contrast, wide view angle, excellent contrast to external light, superior clearness, and less reflection of external light image. The permeable screen includes a front dispersing panel and a lenticular lens sheet disposed at the incident side of the front dispersing panel and forming plural lens surfaces. The permeable screen also includes a Fresnel lens sheet disposed at the incident side of the lenticular lens sheet and forming plural lens surfaces. The front dispersing panel functions as a screen and also provides mechanical strength. The front dispersing panel also possesses parts for mounting and fixing the lenticular lens sheet and Fresnel lens sheet.

Abstract: A color matching system initializes a translator by storing profiles of source and destination color devices which include the coordinates in a calibrated color space of the colorants produced in the source and destination devices and a tonal reproduction curve for each device. Mixing equations and parameters are precomputed to be used in matching calculations of an image including color pixels to be matched. The color gamut is divided into mixing regions in which a given point can be produced by a mixture of two chromatic colorants and the achromatic colorants of the destination device. A technique for selecting a mixing region is included which is based on the slopes of vectors defining the colorants of the destination device, and the sample color to be produced.