Abstract: A light source device has a semiconductor laser for emitting an elliptical divergent beam having a light intensity distribution in an elliptical form; and a beam shaping element for converting an elliptical divergent beam from said semiconductor laser into an approximately circular divergent beam having a light intensity distribution in an approximately circular form; wherein the beam shaping element has a first surface formed of a cylindrical surface and a second surface formed of an anamorphic surface, in order from said semiconductor laser side, and satisfies the predetermined conditional expressions.

Abstract: A diffractive optical element acts as a lens. The optical element has a diffraction grating. The diffractive grating is provided with a plurality of ridges. Each of the ridges has a transmissive surface. A sectional profile of the transmissive surface is composed of a plurality of successively connected strait lines of an identical length. The length varies from one ridge to another.

Abstract: A lens optical system is provided with a cemented lens element formed by cementing two constituent lens elements made of different optical materials together, with a diffractive optical surface formed at the cementing interface between the two constituent lens elements. The two constituent lens elements have at their respective interfaces with air a radius of curvature different from the radius of curvature that they have at the cementing interface.

Abstract: A diffusive optical element exploiting holography is designed in such a way that, the higher the intensity of incident light in a wavelength range, the lower the rate at which the intensity of diffused light in that wavelength range is reduced with increasing angle relative to the maximum intensity direction. Thus, the lower the intensity of incident light in a wavelength range, the narrower the range of angles at which light is diffused in that wavelength range. This makes it possible to use light diffused at angles within a predetermined range relative to the maximum intensity direction, and thereby enhance light use efficiency in a wavelength range in which light intensity is comparatively low. This diffusive optical element is employed in an illumination optical system, which is used to illuminate photographic film from which to read images.

Abstract: An illuminating optical device has a light source that emits non-polarized light; a parallelization converter that converts the light emitted from the light source into essentially parallel light rays; a first lens array that comprises multiple lenses that converge the light rays that strike each of them from the parallelization converter; a polarized light separating element having the configuration of a thin plate with flat top and bottom surfaces, that reflects a first polarized light component of the non-polarized light and transmits the remaining second polarized component, and is located in the light path of the light from the first lens array such that it is angled relative to the light path; a reflection element that reflects the second polarized light component while maintaining its state of polarization and is located near and essentially parallel to the polarized light separating element, wherein the reflection element reflects the light from the first lens array that passed through the polarized l

Abstract: A laser radiating optical system is composed of a laser diode and two mutually independent shaping optical systems. The laser diode emits a laser beam that has a Gaussian intensity distribution and that diverges with a large divergence angle in a first direction and with a small divergence angle in a second direction perpendicular to the first direction. The first shaping optical system makes the intensity distribution even with respect to the first direction, and the second shaping optical system makes the intensity distribution even with respect to the second direction. The shaping optical systems are each composed of a collimator lens and a diffractive element for shaping, and the diffractive elements of the two shaping optical systems are given substantially equal numerical apertures.

Abstract: An optical modulator has a spectral means for diffracting white illumination light into light of predetermined wavelength bands, a liquid crystal layer for modulating the intensity of the light entering a plurality of two-dimensional pixels, a condensing means for condensing the light spectrally diffracted by the spectral means so as to direct the light to each pixel of the liquid crystal layer, and a reflecting means for reflecting the light that passes through the liquid crystal layer in approximately the same direction as the entering light.

Abstract: A projecting image display device is disclosed which includes a display and a micro lens array, where the pixels of the display and the micro lens elements each have non symmetric properties in length and width directions. The micro lens concentrates color-separated light onto pixels of a display device so that light does not hit the black matrix. By providing a display having pixels which are not equal in length and width, pixels corresponding to red (R), green (G) and blue (B) can be arranged in a substantially square area, and by providing a micro lens array which has non symmetric properties in length and width, the color separated light can be concentrated onto the non square display pixels.

Abstract: A thin and light optical device satisfactorily separates light components having different properties. A blazed grating is formed on a surface of a flat-plate-shaped transparent substrate, and a separation coating that reflects or transmits incident light according to the properties of the incident light is provided on the blazed grating. The thus obtained optical device offers a function of separating light into reflected light and transmitted light, and also has a function of diffracting or refracting the thus separated light. As the separation coating, a polarization separation film, dichroic film, angle separation film, or chiral nematic liquid crystal layer is used to separate linearly polarized light components having different polarization planes, light components having different wavelengths, light components incident at different angles of incidence, or circularly polarized light components having different rotation directions.

Abstract: A lens optical system is provided with a cemented lens element formed by cementing two constituent lens elements made of different optical materials together, with a diffractive optical surface formed at the cementing interface between the two constituent lens elements. The two constituent lens elements have at their respective interfaces with air a radius of curvature different from the radius of curvature that they have at the cementing interface.

Abstract: A diffusive optical element exploiting holography is designed in such a way that, the higher the intensity of incident light in a wavelength range, the lower the rate at which the intensity of diffused light in that wavelength range is reduced with increasing angle relative to the maximum intensity direction. Thus, the lower the intensity of incident light in a wavelength range, the narrower the range of angles at which light is diffused in that wavelength range. This makes it possible to use light diffused at angles within a predetermined range relative to the maximum intensity direction, and thereby enhance light use efficiency in a wavelength range in which light intensity is comparatively low. This diffusive optical element is employed in an illumination optical system, which is used to illuminate photographic film from which to read images.

Abstract: A zoom lens system has the first and second lens units. During zooming from a wide-angle end to a telephoto end, the lens units are moved to decrease a distance therebetween. The first lens unit has a positive refractive power. The second lens unit has a negative refractive power. The zoom lens system is provided with at least one surface having a power to diffract light.

Abstract: A designing method of a zoom optical system wherein each zoom unit is formed of one optical element has steps of: selecting a spherical system, a gradient index system or a diffractive optical system and at least one more system as systems constituting the degree of design freedom of each zoom unit, optimizing each zoom unit with respect to third-order aberrations and chromatic aberration; and using an optical solution obtained by said optimizing step as the design start data.

Abstract: A zoom lens system has, from the object side, a first lens unit having a negative optical power and including at least one diffractive optical surface and a second lens unit having a positive optical power and including at least one diffractive optical surface. A distance between the first and second lens units varies during zooming operation.

Abstract: A zoom lens system includes a first lens unit having a negative optical power, located closer to an object side, and a second lens unit having a positive optical power, located farther from the object side. Zooming is accomplished by varying the spacing between the first and second lens units. The surface of at least one lens element in the two lens units is a diffractive optical surface. At least one surface of the lens element is an aspherical surface.

Abstract: A zoom lens system has the first and second lens units. During zooming from a wide-angle end to a telephoto end, the lens units are moved to decrease a distance therebetween. The first lens unit has a positive refractive power. The second lens unit has a negative refractive power. The zoom lens system is provided with at least one surface having a power to diffract light.

Abstract: A viewfinder optical system has a relay lens system. The relay lens system focuses a primary image to form a secondary image. The relay lens is provided at an optical conjugate point with respect to a pupil. A surface of the relay lens system has an optical power of diffraction. The surface is positioned between the primary image and the optical conjugate point. The surface also has optical power of refraction.

Abstract: A method of designing a spatial phase modulation element which has a plurality of hologram surfaces with mutually different phase patterns, and a spatial phase modulation element produced in the method. The spatial phase modulation element is designed to have a variable-phase medium located on one side of each of the hologram surfaces and modulating means for modulating the phase patterns of the hologram surfaces independently of each other. Further, if the number of output patterns to be obtained with the spatial phase modulation element is n and if the number of hologram surfaces is N, the spatial phase modulation element is so designed as to meet the condition n.gtoreq.N+2, N.gtoreq.2.

Abstract: An optical system has a diffractive optical element. A diffractive optical surface of the optical element has a blaze-shaped diffraction grating. The grating heights are smaller in the peripheral region of the grating than in the central region of the grating around its optical axis. The optical element acts as a lenses a result of light rays being deflected by the light-diffracting action of the diffractive optical surface.

Abstract: A zoom lens system includes, from the object to image side, a first lens unit of a positive refractive power having a first lens element with a power to both diffract and refract light. A second lens unit has a negative refractive power and may include a second lens element having both the power to diffract and refract light, and it least a third lens unit is included. A zooming operation is performed by varying the distances between the respective first, second, and third lens units.