Abstract: An apparatus for displaying a stereoscopic image including right-eye and left-eye image display devices displaying right-eye and left-eye images, respectively, right-eye and left-eye magnifying lenses forming enlarged virtual right-eye and left-eye images, respectively, an eye point camera for detecting a point in a sight at which a viewer gazes, a parallax calculating circuit for deriving a parallax of the gazed point, a image shift amount calculating circuit for calculating an amount of image shift in accordance with the parallax, and an image shift circuits for shifting the right-eye and left-eye images horizontally in opposite direction by the same amount such that a distance of convergence with respect to the gazing point is substantially fixed. It is preferable to shift the right-eye and left-eye images such that the distance of convergence becomes substantially equal to a viewing distance from eyes of the viewer to a virtual image plane.

Abstract: A head-mounted image display apparatus having an exit pupil that is enlarged without causing an increase in the size of a relay optical system or a reduction in the size of a projected image. The head-mounted image display apparatus has an image display device (1) having a display surface for displaying an image, a relay optical system (2) for transmitting the image displayed on the display surface of the image display device (1) to form an image of the display surface, and an ocular optical system (4) for projecting the image transmitted by the relay optical system inside an observer's eyeball as an enlarged image. A numerical aperture (NA) enlarging element is disposed at a position conjugated with the display surface with respect to the relay optical system (2). Thus, pupil alignment is facilitated without causing an increase in the size of the relay optical system (2) or a reduction in the size of the projected image.

Abstract: An image display apparatus, e.g., a head-mounted image display apparatus, which uses a compact optical system and yet has minimal aberrations and a large exit pupil diameter. The image display apparatus has a liquid crystal display device (2), and an ocular lens (3) for projecting an image displayed by the liquid crystal display device (2) on a user's retina. A pair of first and second diffraction gratings (11) and (12) are provided in an optical path lying between the ocular lens (3) and an exit pupil (6) formed by the ocular lens (3). The first and second diffraction gratings (11) and (12) are arranged so that the angle of diffraction caused by the second diffraction grating (12) for each wavelength of the displayed image is approximately coincident with the angle of diffraction caused by the first diffraction grating (11).

Abstract: A head mounted image display apparatus capable of performing a stereoscopical viewing, having first and second image display sections and displaying first and second images each having parallax on these first and second image display sections is disclosed.

Abstract: A display apparatus of the type that is fitted to the user's head or face, and having a higher resolution in a first region of the display than that of the remaining area of the display, without increasing the size of the display. As an example, an image of the characters "ABC", for example, are generated or received. However, it might be desired that the center character "B", for example, be displayed at a higher resolution than that of the characters "A C". To accomplish this, the original image "ABC" is divided into an image of "A C" and an image of "B". Then, the image of "B" is electrically distorted and formed on a screen such that the image of "B" is larger in size than the image of "A C". An ocular optical system including an optical element effects a second distortion of the image to correct the electrically created distortion.

Abstract: An image display apparatus which has a stable field angle independently of each individual observer and the observer's eye point, and which is capable of correcting distortion of an observation image, or which allows the corners of an image display device to be relatively bright. The apparatus has an image display device (3), a device (4) for illuminating it, and an ocular optical system (2) for leading the image of the image display device (3) to an observer's eyeball (1). A field stop (5) is provided in the ocular optical system (2) or between the ocular optical system (2) and the image display device (3), and a light-blocking device (6) is provided between the image display device (3) and the illuminating device (4) such that the distance from the field stop (5) to the image display device (3) and the distance from the image display device (3) to the light-blocking device (6) are approximately equal to each other.

Abstract: An image display apparatus, e.g., a head-mounted image display apparatus, which uses a compact optical system and yet has minimal aberrations and a large exit pupil diameter. An image displayed on a liquid crystal display device (2) is projected as an enlarged image in a user's eyeball by a convex lens (3). Prism arrays (13 and 14) having the same vertex angle are disposed in parallel to each other between the convex lens (3) and an exit pupil (6) so that the array directions coincide with each other. A parallel beam of light passed through the convex lens (3) has a pupil diameter (a) determined by the numerical aperture of an illumination system (1). The parallel beam first enters the prism array (13) and separates into light beams traveling in four different directions by the prism refracting action. These light beams then enter the prism array (14), which has the same vertex angle as that of the prism array (13). Consequently, the light beams are refracted again to become parallel to each other.

Abstract: The optical system of the invention includes a phase type Fresnel zone plate 5. The zone plate 5 includes thereon a central zone C located around the optical axis, through which light flux 2 emanating from an object and having a relatively small divergence angle passes, and a peripheral zone P located on the outside thereof. The central and peripheral zones C and P have given Fresnel pitches and blazing angles, so that the peripheral zone P can make use of diffraction higher in order than that used by the central zone C to obtain the desired refractive power. Although the minimum pitch of the phase type Fresnel plate zone is thus relatively larger in the peripheral zone P, the optical system is not only satisfactory in terms of the effect on correction of chromatic aberration and refractive power but ensures a good image surface contrast as well.

Abstract: A head-mounted see-through display which enables an outside image and an electronic image to be selectively observed by making a liquid crystal shutter transparent or opaque. To eliminate the problem that during the observation of the electronic image the outside image is undesirably seen through the peripheral region of the electronic image, display light from a two-dimensional display device (11) is first transmitted by a half-mirror (12), and the transmitted light is reflected by a concave mirror (13). Then, the reflected light is reflected by the half-mirror (12) so as to be led to the observer's eye as an enlarged image. To prevent the outside light from entering the eye through the half-mirror (12) during the observation of the electronic image, a negative or positive type TN or STN liquid crystal shutter (10) is disposed in front of the half-mirror (12).

Abstract: An image display apparatus, e.g., a head-mounted display apparatus, which uses a half-mirror or a beam splitter prism and yet has an even more compact structure and provides a favorably flat image surface. A half-mirror (S) is obliquely disposed in front of an observer's eyeball (1), and an image display device (3), e.g., a liquid crystal display device, and a magnifying reflecting mirror (4) are disposed to face each other across the half-mirror (S) and to extend parallel to the observer's line of sight. To widen the field angle without increasing the size and weight of the optical system considerably, at least one surface (L) having positive refractive power is interposed between the eyeball (1) and the half-mirror (S). An even more compact arrangement is obtained by using a beam splitter prism in place of the half-mirror (S).

Abstract: An image display apparatus, for example, a spectacle-type image display apparatus, which is capable of reproducing a high-definition image by projecting pixels at a proper pitch on the retina in the user's eye. The image display apparatus includes a microlens array (3) having microlenses provided to correspond respectively to the pixels to converge beams of light emerging from the pixels, and a condenser lens (4) for converting beams of light emerging from the microlens array (3) into parallel beams of light and for leading them to the user's eyeball (7). Thus, a beam of light emerging from each pixel enters the microlens array (3), and the beam of light emerging from the microlens array (3) enters the condenser lens (4) where it is converted into a parallel beam of light, which is then led to the eyeball (7). Since an array of pixels is reconstructed at a proper pitch on the retina (6) in the eyeball (7), the user can perceive an image.

Abstract: An image observation device includes a two-dimensional image display element, a relay optical system for forming a real image of an image displayed on the two-dimensional image display element, an eyepiece optical system for forming a magnified image of the real image and bending the optical axis, and a supporting member for supporting the eyepiece optical system to be located directly before the eyes of the user. This arrangement makes it possible to provide the image observation device which is small in size and high in magnification for observation.

Abstract: In order to substantially reduce the time required for examination and to enable the structure of the microscope apparatus for examining a wafer to be made in a compact size, the apparatus comprises a wafer examination unit provided midway on the transportation course of the wafer transporting means for being able to move the wafer under examination independently of the direction of its transporation, and an objective disposed above the wafer examination unit for being able to move along the upper face of the wafer which is held at the position of examination and in a direction different from the direction of the transportation.

Abstract: A microscope wherein, in order that the observing position may be variable over a wide range of a sample to be observed without requiring a large objective, the objective optical system is so formed as to be movable in parallel with the sample surface and the light path length between the objective optical system and eyepiece optical system is made variable by moving the objective optical system.

Abstract: An objective to be used with a single-objective type binocular stereomicroscope which comprises an objective for forming an afocal image, and two observation optical systems for observing the afocal image by the right and left eyes, the objective being arranged to fulfill the condition shown below so as to thereby prevent the error in the sense of depth and distance from occurring.

Abstract: A transmission type illuminating device for stereomicroscopes formed by arranging in the order mentioned a light source, a collector lens, a pair of light source image forming lenses located in positions symmetrical with respect to the optical axis of the collector lens and a relay lens for light source images arranged on the same optical axis as of the collector lens in order that a uniform bright illumination may be always made irrespective of the magnification and a wide uniform oblique light illumination may be also easily made.