Abstract: A display device includes a transparent substrate, a plurality of electroluminescent elements arranged on the transparent substrate, transparent members respectively covering the electroluminescent elements, and reflection films formed respectively on the surfaces of the transparent members. Each of the electroluminescent elements is formed by sequentially laying a transparent electrode, an electroluminescent layer and a reflector electrode on the transparent substrate. Each of the transparent members has a profile of a frustum of pyramid or cone, or partly has a curved surface showing a positive curvature and a curved surface showing a negative curvature at the portion held in contact with the transparent substrate.

Abstract: A diffractive optical element includes a plurality of laminated diffraction grating surfaces. Each of the diffraction grating surfaces is formed to have a sufficiently small grating thickness as compared with a grating pitch thereof.

Abstract: In a lens system having one or a plurality of diffracting surfaces and one or a plurality of refracting surfaces, a power of each surface and a distance between the surfaces are set such that an optical characteristic of the lens system, such as a focal length (focal point) and/or a spherical aberration, remains substantially unvarying relative to temperature variations within a predetermined range and that an achromatic effect is substantially attained for the focal length (focal point) and/or the spherical aberration within a predetermined region of wavelength.

Abstract: A display device comprises a transparent substrate, a plurality of electroluminescent elements arranged on the transparent substrate, transparent members respectively covering the electroluminescent elements, and reflection films formed respectively on the surfaces of the transparent members. Each of the electroluminescent elements is formed by sequentially laying a transparent electrode, an electroluminescent layer and a reflector electrode on the transparent substrate. Each of the transparent members has a profile of a frustum of pyramid or cone, or partly has a curved surface showing a positive curvature and has a curved surface showing a negative curvature at the portion held in contact with the transparent substrate.

Abstract: In a lens system having one or a plurality of diffracting surfaces and one or a plurality of refracting surfaces, a power of each surface and a distance between the surfaces are set such that an optical characteristic of the lens system, such as a focal length (focal point) and/or a spherical aberration, remains substantially unvarying relative to temperature variations within a predetermined range and that an achromatic effect is substantially attained for the focal length (focal point) and/or the spherical aberration within a predetermined region of wavelength.

Abstract: A diffractive optical element includes a plurality of laminated diffraction grating surfaces. Each of the diffraction grating surfaces is formed to have a sufficiently small grating thickness as compared with a grating pitch thereof.

Abstract: An original sensing device for sensing the presence/absence of an original placed on an original tray of a document feeder by using an output signal from a photodetector which receives a light beam emitted by a light projector and reflected by the original tray, including a projecting/photodetecting unit including the light projector and the photodetector, and an optical member interposed between the projecting/photodetecting unit and the original tray. The light projector and the photodetector are arranged to oppose said original tray such that a projecting optical axis and a photodetecting optical axis are substantially parallel to each other.

Abstract: A color image reading apparatus includes a light receiving device having a plurality of line sensors disposed on a surface of a common substrate, an imaging optical system for forming an image of an object, a blazed diffraction grating, disposed in an optical path between the imaging optical system and the light receiving device, for color-separating a beam from the object into a plurality of color beams, a first optical element provided near a position where the plurality of color beams are focused in a sub scanning cross section by the imaging optical system and a second optical element provided in an optical path between the first optical element and the light receiving device. The plurality of color beams color-separated by the blazed diffraction grating are focused on the light receiving device through the first optical element and the second optical element.

Abstract: An optical modulator includes a first diffraction grating for separating a light flux of a wide wavelength band into light fluxes of given wavelength bands. The optical modulator further includes an optical modulation element for modulating the separated light fluxes through corresponding picture elements, respectively, and outputting them. The optical modulator further includes a second diffraction grating for synthesizing the modulated light fluxes outputted from the optical modulation element, wherein the first diffraction grating, the optical modulation element and the second diffraction grating are integrally structured.

Abstract: A color image reading apparatus is provided with a line sensor, an imaging optical system and a blazed diffraction grating. A color image is read by the line sensor through a rotatable reflective one-dimensional blazed diffraction grating serving as the color separation means. At least three color lights color-separated by the diffraction grating is synchronized with the scanning reading speed to rotate the diffraction grating in at least three directions, so that the reading of the color image is conducted by use of one line sensor.

Abstract: An image reading apparatus is provided with a light-receiving device, an imaging optical system and a blazed diffraction grating. In the light-receiving device, a plurality of line sensors are arranged on the same substrate. An image of an object to be imaged is formed on the light-receiving device by the imaging optical system. The blazed diffraction grating is arranged in an optical path between the imaging optical system and the light-receiving device. The blazed diffraction grating color-separates a light beam from the object to be imaged into a plurality of light components. The diffraction grating is so constructed to have grating lines with at least two different grating heights.

Abstract: A color image reading apparatus includes a plurality of line sensors formed by arranging a plurality of one-dimensional sensor arrays on a single substrate, a focusing optical system for focusing an object on the sensors, and a volume hologram, arranged in the optical path between the focusing optical system and the sensors, for color-separating light from the object into a plurality of color components and guiding the plurality of color components to the corresponding one-dimensional sensor arrays.

Abstract: An image reader comprises a monolithic 3-line sensor having three one-dimension sensor arrays such as solid-state imaging devices arranged on one substrate with each array being spaced by a predetermined distance along a direction perpendicular to the array direction, a focusing optical system for focusing an image of an object onto the sensor, and a one-dimension blazed diffraction grating arranged in a light path between the focusing optical system and the sensor, closer to the sensor than to an exit pupil of the focusing optical system for spectroscopically separating a light from one point on the object by a diffraction effect to color-decompose it into three colors perpendicularly to the array and directing the color-decomposed lights to the corresponding sensor arrays. Distances from a center sensor array of the 3-line sensor to two other sensor lines are different from each other.

Abstract: A color reading apparatus includes a reflection type one dimensional blazed diffraction grating for color separation which is provided on an optical path between an imaging optical system for focusing a color image on a photosensor, and the photosensor in which three line sensors are disposed on a common substrate. The pitch of the diffraction grating varies in a direction of the pitch so as to control the reflective diffraction angle from reflection points resulting from different incident angles on the diffraction grating and to prevent the occurrence of a blur of .+-.1st-order diffracted light in the pitch cross section on the diffraction grating.

Abstract: An image reading device includes a plural-line sensor containing plural line sensor arrays formed on a substrate, a telecentric imaging optical system for forming the image of an object on the sensor, and a blazed diffraction grating positioned in the optical path between the imaging optical system and the sensor and adapted to separate the light from the object into plural color components and to guide the color-separated light to respectively corresponding sensor arrays.

Abstract: An image reading apparatus comprises a plural-line sensor comprising a plurality of one-dimensional sensor arrays disposed on one and the same substrate, an imaging optical system for imaging an object on the sensor, and a brazed diffraction grating disposed in the optical path between the imaging optical system and the sensor for color-resolving a light beam from the object into a plurality of lights and directing the color-resolved lights to the sensor arrays corresponding thereto, the number of steps of the staircase structure of the diffraction grating being four or more.

Abstract: A color image reading apparatus comprises a plurality of line sensors, an optical system for forming an image of a subject, a blazed diffraction grating inserted in light path between the optical system and the sensors, and a slit inserted in light path between the subject and the optical system. The blazed diffraction grating separates light beams from the subject into plurality color lights and directs them to their corresponding sensor arrays. The slit has an aperture, the size of which in the array direction of the sensors is longer than that in the direction perpendicular to the array direction of the sensors. By construction of the apparatus according to the present invention, noise light can be prevented so as to read high accuracy digital color image.

Abstract: A light scanning optical system of an image output scanner in which a light beam incident from a light source through an irradiating optical system is applied to an electro-mechanical light modulator comprising a number of elements capable of deflecting the incident light beam in at least two directions in conformity with an input signal and arranged in the main scan direction, and image information is prepared by the change-over of the direction of deflection of each of the elements, whereafter only a signal light is projected onto a photosensitive member by a projection optical system is characterized in that the shape of at least one of the irradiating and projection optical system is flat in the main scan direction and the electro-mechanical light modulator is irradiated in the form of a slit.

Abstract: An image forming apparatus including a movable photosensitive member, a first optical device for projecting light from an original onto the photosensitive member, second optical device for projecting a dot pattern to the photosensitive member before, upon or after formation of the image projected onto the photosensitive member by the first optical device, the second exposure device projecting onto the photosensitive member a beam modulated in accordance with a signal modulated to provide the dot pattern, and a selector device for selection between a first mode wherein an image is formed by the first optical device and a second mode wherein an image is formed by the first and second optical device.

Abstract: An image reading apparatus comprises a multiline sensor on which a plurality of linear sensor arrays are arranged on and a single substrate, a focusing optical system for focusing an object image on the multiline sensor. A blazed diffraction grating is disposed in an optical path between the focusing optical system and the multiline sensor, for color-separating light from the object into a plurality of light components, and for guiding the color-separated light components to the corresponding sensor arrays. The grating thickness of the blazed diffraction grating varies in correspondence with an angle of light incident on the blazed diffraction grating.