Abstract: There is provided an optical device, including a light-transmitting substrate having a refractive index, at least two major surfaces and edges, an optical element for coupling light waves into the substrate for effecting total internal reflection, at least one element carried by the first substrate for coupling light waves out of the substrate, and a first transparent plate, having at least two major surfaces, one of the major surfaces of the first transparent plate being optically cemented, with a first optical adhesive having a refractive index, to one of the major surfaces of the light-transmitting substrate, defining a first interface surface, light waves coupled inside the substrate are partially reflected from the interface plane and partially pass through it, wherein the refractive index of the optical adhesive is different than the refractive index of the light transmitting substrate.

Abstract: An optical device includes a light-transmitting substrate, input and output apertures, eye-motion box, intermediate element outside of the substrate for coupling light waves into the substrate through the input aperture, a first reflecting surface between two major surfaces of the light-transmitting substrate for reflecting the coupled-in light waves to effect total internal reflection from the major surfaces of the substrate, a second flat reflecting surface parallel to the first reflecting surface located between the major surfaces of the light-transmitting substrate, for coupling light waves out of the substrate, and an optical element for redirecting light waves coupled-out from the substrate through the output aperture, into the eye-motion-box. The input aperture is substantially smaller than the output aperture, active areas of the first and second reflecting surfaces are similar, and each of the coupled light waves covers the entire aperture of the eye-motion-box.

Abstract: An optical device, having at least first and second light-transmitting substrates, each having at least two external surfaces and an input aperture and an output aperture. The external surface of the first light-transmitting substrate is optically cemented to an external surface of the second light-transmitting substrate by an optical adhesive defining an interface plane. The refractive index of the optical adhesive is substantially lower than the refractive index of the first substrate. Part of the light waves entering the device through the input aperture and exiting the device through the output aperture impinge on the interface plane of the first substrate having incidence angles smaller than the critical angle. Another part of the light waves impinging on the interface plane have incidence angles higher than the critical angle. The interface plane is substantially transparent for the light waves impinging on interface plane having incidence angles smaller than the critical angle.

Abstract: There is provided an optical device, including a light-transmitting substrate, having at least two parallel major surfaces, edges and an output aperture, an optical element for coupling light waves into the substrate to effect total internal reflection, at least one redirecting element positioned outside of the substrate, and at least one reflecting surface having at least one active side located between the two major surfaces of the light-transmitting substrate for coupling light waves out of the substrate, wherein light waves trapped inside the substrate are coupled out from the substrate through the output aperture substantially inclined in relation to the normal to the substrate major surfaces and are reflected from the redirecting element into a viewer's eye, and wherein the redirecting element is a single flat reflecting surface parallel to the major surfaces of the substrate.

Abstract: There is provided an optical device, including a light-transmitting substrate having at least two major surfaces and edges, a display source based on a time-sequential color imaging, characterized by a frame time, three different primary colors, and coupled-in brightness, an optical element for coupling light waves from the display source into the substrate to effect total internal reflection, at least one flat reflecting surface located between the two major surfaces of the light-transmitting substrate for coupling light waves out of the substrate, and a dynamic partially reflecting element for re-directing the coupled-out light waves into a viewer's eye, wherein the transmittance and the reflectance of the dynamic partially reflecting element is dynamically controllable to yield high reflection in each one of the three primary colors, while simultaneously having high transmittance of two other colors of the three primary colors.

Abstract: There is provided an optical display system, including a light source, a control unit, and an array of at least two pixels, each of the pixels being a juxtaposed double grating element, comprising a first grating and a second grating spaced apart at a constant distance from each other, each of the two gratings having at least two edges, at least one sequence of a plurality of lines and apertures, the spacing between the lines gradually changing over the aperture of the gratings, the first grating diffracting a light wave from the light source towards the second grating, the light wave further diffracted by the second grating as an output light wave in a given direction, wherein for each of the pixels the direction of the output light wave from the second grating is separately, dynamically and externally controlled by the control unit.

Abstract: There is provided an optical device, including a light-transmitting substrate having at least two parallel major surfaces, edges and an output aperture, an optical element for coupling light waves into the substrate to effect total internal reflection, a plurality of redirecting elements positioned outside of the substrate comprising at least two spaced-apart redirecting elements having a selectable laterally displaceable reflection-transmission ratio, and at least one reflecting surface having at least one active side located between the two major surfaces of the light-transmitting substrate for coupling light waves out of the substrate, wherein light waves trapped inside the substrate are coupled out from the substrate through the output aperture substantially inclined in relation to the normal to the substrate major surfaces, and are reflected from the redirecting elements into a viewer's eye, and wherein at least one of the redirecting elements is lateral displaceable in relation to another redirecting el

Abstract: An optical device, having at least first and second light-transmitting substrates, each having at least two external surfaces and an input aperture and an output aperture. The external surface of the first light-transmitting substrate is optically cemented to an external surface of the second light-transmitting substrate by an optical adhesive defining an interface plane. The refractive index of the optical adhesive is substantially lower than the refractive index of the first substrate. Part of the light waves entering the device through the input aperture and exiting the device through the output aperture impinge on the interface plane of the first substrate having incidence angles smaller than the critical angle. Another part of the light waves impinging on the interface plane have incidence angles higher than the critical angle. The interface plane is substantially transparent for the light waves impinging on interface plane having incidence angles smaller than the critical angle.

Abstract: There is provided an optical device, including an input aperture, an output aperture, at least first and second light-transmitting substrates each having two major surfaces and edges, an input surface for coupling light waves into the substrate for effecting total internal reflection inside the substrate, and an output surface for coupling light waves out of the substrate, a major surface of the first substrate is attached to a major surface of the second substrate and the input surface of the first substrate is a partially reflecting surface, such that part of the light waves passing through the input aperture is partially reflected by the partially reflecting input surface and coupled into the first substrate and another part passes through the partially reflecting input surface and is coupled by the input surface of the second substrate into the second substrate.

Abstract: There is provided an optical system, including a light source, a control unit, and at least one juxtaposed double grating element, including a first grating and a second grating having grating functions, the gratings being spaced apart at a constant distance from each other, each of the two gratings having a center and at least one edge and comprising at least one sequence of a plurality of lines, wherein the spacing between the lines gradually changes from the center of the grating to the edges, the sequence of the plurality of lines of at least one of the gratings has a radial symmetry, and wherein the first grating diffracts a light wave from the light source towards the second grating and is further diffracted by the second grating as an output light wave in a given direction.

Abstract: An optical device, having at least first and second light-transmitting substrates, each having at least two external surfaces and an input aperture and an output aperture. The external surface of the first light-transmitting substrate is optically cemented to an external surface of the second light-transmitting substrate by an optical adhesive defining an interface plane. The refractive index of the optical adhesive is substantially lower than the refractive index of the first substrate. Part of the light waves entering the device through the input aperture and exiting the device through the output aperture impinge on the interface plane of the first substrate having incidence angles smaller than the critical angle. Another part of the light waves impinging on the interface plane have incidence angles higher than the critical angle. The interface plane is substantially transparent for the light waves impinging on interface plane having incidence angles smaller than the critical angle.

Abstract: There is provided a frame time-based optical display system, having a control unit, a two-dimensional array of more than two pixels, each of the pixels being an element having a front surface, emitting an output light wave, each of the pixels includes means for controlling the amplitude and direction of the output light wave for each time of the display, wherein for each of the pixels the direction of the output light wave is separately, dynamically and externally controlled by the control unit.

Abstract: There is provided an optical display system, including a light source, a control unit, and an array of at least two pixels, each of the pixels being a juxtaposed double grating element, comprising a first grating and a second grating spaced apart at a constant distance from each other, each of the two gratings having at least two edges, at least one sequence of a plurality of lines and apertures, the spacing between the lines gradually changing over the aperture of the gratings, the first grating diffracting a light wave from the light source towards the second grating, the light wave further diffracted by the second grating as an output light wave in a given direction, wherein for each of the pixels the direction of the output light wave from the second grating is separately, dynamically and externally controlled by the control unit.

Abstract: An optical device includes input and output apertures (86, 89), a light-transmitting substrate (64), a coupling-in element (55) positioned outside of the substrate for coupling light waves having a field-of view into the substrate, a first flat reflecting surface (65) located between two major surfaces (70,72) of the light-transmitting substrate for total internal reflection of the coupled-in light waves from the major surfaces, and a second flat reflecting surface (67) located between the two major substrate surfaces for coupling light waves out of the substrate for redirecting into a viewer's eye by an optical element (80). The substrate and coupling-in element (55) are formed of substantially different optical materials and the ratio between the fields of view of the light waves coupled-out from the substrate into the viewers' eye and of the light waves coupled inside the substrate, is substantially bigger than the refractive index of the substrate.

Abstract: There is provided an optical device, including a light-transmitting substrate having a refractive index, at least two major surfaces and edges, an optical element for coupling light waves into the substrate for effecting total internal reflection, at least one element carried by the first substrate for coupling light waves out of the substrate, and a first transparent plate, having at least two major surfaces, one of the major surfaces of the first transparent plate being optically cemented, with a first optical adhesive having a refractive index, to one of the major surfaces of the light-transmitting substrate, defining a first interface surface, light waves coupled inside the substrate are partially reflected from the interface plane and partially pass through it, wherein the refractive index of the optical adhesive is different than the refractive index of the light transmitting substrate.

Abstract: There is provided an optical device, including an input aperture, an output aperture, at least first and second light-transmitting substrates each having two major surfaces and edges, an input surface for coupling light waves into the substrate for effecting total internal reflection inside the substrate, and an output surface for coupling light waves out of the substrate, a major surface of the first substrate is attached to a major surface of the second substrate and the input surface of the first substrate is a partially reflecting surface, such that part of the light waves passing through the input aperture is partially reflected by the partially reflecting input surface and coupled into the first substrate and another part passes through the partially reflecting input surface and is coupled by the input surface of the second substrate into the second substrate.

Abstract: An optical device, having at least first and second light-transmitting substrates, each having at least two external surfaces and an input aperture and an output aperture. The external surface of the first light-transmitting substrate is optically cemented to an external surface of the second light-transmitting substrate by an optical adhesive defining an interface plane. The refractive index of the optical adhesive is substantially lower than the refractive index of the first substrate. Part of the light waves entering the device through the input aperture and exiting the device through the output aperture impinge on the interface plane of the first substrate having incidence angles smaller than the critical angle. Another part of the light waves impinging on the interface plane have incidence angles higher than the critical angle. The interface plane is substantially transparent for the light waves impinging on interface plane having incidence angles smaller than the critical angle.

Abstract: There is provided a method for fabricating an optical device having a light wave transmitting substrate with at least two major surfaces and edges, input and output reflecting surfaces carried by the substrate, for producing a substrate allowing light waves to traverse the substrate between the two major surfaces, the method including attaching to each other a plurality of substantially transparent flat plates arranged in a stack, slicing the stack to form a substrate with two major surfaces, and coupling-in and coupling-out reflecting surfaces, with major surfaces being parallel to each other and not parallel to the input or the output surfaces, grinding or polishing the substrate, and cutting the substrate to final dimensions.

Abstract: There is provided an optical device, including a light-transmitting substrate having at least two parallel major surfaces, edges and an output aperture, an optical element for coupling light waves into the substrate to effect total internal reflection, at least one first reflecting surface having at least one active side, located between the two major surfaces of the light-transmitting substrate for coupling light waves out of the substrate, and a partially reflecting element positioned outside of the substrate, wherein light waves coupled out from the substrate through the output aperture, are partially coupled back into the substrate by the partially reflecting element.

Abstract: An optical system, including an input aperture, an output aperture, and at least first and second light transmitting substrates. Each substrate has two major surfaces parallel to each other and at least one slanted edge. An input element couples light waves impinging on the input element into the light-transmitting substrates for effecting total internal reflection inside the light-transmitting substrates. An output element couples light waves out of the light-transmitting substrates. A major surface of the first light-transmitting substrate is optically attached to a major surface of the second light-transmitting substrate defining an interface. For each of the light-transmitting substrates, light waves coupled inside the substrate by the input element are substantially totally internally reflected from the interface plane.