Minolta Company, Ltd.

Yasushi Kobayashi

Hideki Nagata

Kenji Ishibashi

Soh Ohzawa

Yasushi Tanijiri

Ichiro Kasai

Takeshi Endo

Hiroaki Ueda

Manami Kuiseko

Kohtaro Hayashi

Akira Sato

Hiroyuki Yamasaki

Yasumasa Sugihara

Takatoshi Ishikawa

Tetsuya Noda

Yoshie Shimizu

An optical head which has a prism with an incident section, an internal reflective surface and an emergent surface, and an optical head device which employs the optical head. Light emitted from a light source is incident to the prism through the incident section, reflects at least once on the internal reflective surface and is converged in the vicinity of the emergent surface. Then, the light effuses through the emergent surface as near field light.

Optical head and optical head device

An image observation device which is so arranged that a user can look an image in through an ocular window thereof with the device being fitted to the user's head for example, that the image changes in linkage with movement of the user's head, and that unnecessary change of the image is prevented during the observation. The image observation device includes an eye access detector for detecting whether the user's eyes approach thereto or not, and includes, a controller by the operation of which the image changes in linkage with movement of the user's head only if the eye access detector detects that the user's eyes approach thereto, and by the operation of which the image does not change in linkage with movement of the user's head if the eye access detector does not detect that the user's eyes approach thereto.

Image observation apparatus

An image display apparatus forms illumination light from a light source into image light by using a reflective display device, and directs the image light through an eyepiece optical system to an eye to present a virtual image of the image carried by the image light. To realize an image display apparatus of this type that is compact, affords a sufficiently long eye relief, and offers wide-field, high-quality images, a combiner for making the optical path of the illumination light from the light source overlap with that of the image light is disposed inside the eyepiece optical system, a positive lens is provided in the rear potion of the eyepiece optical system between the display device and the combiner, a concave reflective surface is provided in the front portion of the eyepiece optical system between the combiner and the observation point, and the eyepiece optical system is designed to be overtelecentric as a whole.

Image display apparatus

An image display apparatus has an image display device for displaying an image, an eyepiece optical system, including a holographic magnifying optical element, for magnifying and projecting the image, and a holographic filter, disposed either as part of the image display device or in the optical path between the image display device and the eyepiece optical system, for restricting the wavelength range of the image light.

A reflecting microoptical system is formed of only two optical surfaces having a continuous configuration, and has a simple configuration suitable for glass molding. Different combinations of convex, planar and concave surfaces are disclosed for the two optical surfaces, to provide different advantageous properties. In preferred embodiments of the invention, at least one, and in some cases both, of the optical surfaces have an aspherical shape to correct for aberrations.

Reflecting microoptical system

An image display apparatus has a reflective display element for displaying a two-dimensional image on a display plane, a light source for emitting illuminating light for illuminating said display plane, a magnifier optical system for magnifying and projecting said two-dimensional image, and an optical member which is composed of a medium having a refractive index greater than or equal to unity and has at least three optical planes of a first plane, a second plane, and a third plane. The magnifier optical system is substantially in concentricity with said display plane; the illuminating light from said light source passes through said first plane and then through said second plane, thereby illuminating said display plane; and the reflected light from said display plane passes through said second plane and is then reflected in said first plane, thereby passing through said third plane and being incident on said magnifier optical system.

An image display apparatus has a signal input portion for receiving an image signal, an image compensator for electrically compensating the image signal for distortion so that a left and a right image displayed in an observer's left and right eyes have identical distortion and then outputting a left and right image signal that correspond to the left and right images, a signal switcher for switching between the left and right image signals output from the image compensator so as to output the left and right images alternately chronologically, a single two-dimensional image display device for displaying a two-dimensional image in accordance with the image signal output from the signal switcher, a pair of left and right eyepiece optical systems for directing image light exiting from the two-dimensional image display device to the observer's left and right eyes so that the two-dimensional image is displayed as a virtual image in the observer's eyes, and an optical path switcher for time-divisionally switching optical paths from the two-dimensional image display device to the observer's eyes in synchronism with switching between the left and right image signal output from the signal switcher so that the image light enters either the observer's left or right eye at a time.

A screen image observing device and method provides the sensations of virtual reality to the observer and reduces, to the extent possible, the discrepancy that is perceived by the observer between the movement of the observer's head and the displayed screen image. The device has a head tracking means, which detects the movement of the observer's head, and a screen image generating means, which generates image data based upon the result of the detection performed by the head tracking means. Image data is supplied to a display means.

Screen image observing device and method

A head-mounted display device and an eyepiece optical system suitable for use in the head-mounted display device is provided. The eyepiece optical system is capable of enlarging and displaying, to an eye of an observer, an image displayed on a two-dimensional display element. The eyepiece optical system includes, sequentially from the observer's eye, an aspherical resin lens, a spherical glass lens, and a polarization-conversion element disposed between the spherical glass lens and the two-dimensional display element. On a surface of the aspherical resin lens is provided a circularly-polarized-light-selective reflecting-transmitting surface for selectively reflecting and transmitting projection image light from the two-dimensional display element, depending on a rotation direction of circularly-polarized rays of the projection image light.

Eyepiece optical system

A compact, high resolution projection imaged display device using a reflective-type display element which uniformly illuminates the entirety of the display element without reducing illumination efficiency and ensures viewing conditions of excellent and uniform brightness extending to the fringe of the field of view is provided by an illumination optical system for redirecting illumination light from an illumination light source onto a reflective-type display element. The reflective-type display element reflects light into the viewing optical system wherein the illumination optical system is constructed so as to have an approximate conjugate relationship between the pupil of the user and the illumination light from the illumination light source.

Projection image display device using a reflective type display element

An image display apparatus is provided with a screen having retro-reflectivity, a liquid crystal display device displaying an image, a projection optical system projecting the light of the liquid crystal display device onto the screen, and a beam magnifier located close to the screen and magnifying the light beams, included in the projected light, expressing individual points of the image. The beam magnifier is composed of a diffraction optical element or a diffusing plate, and magnifies each light beam so that the magnification is larger in the direction of the horizontal field of view than in the direction of the vertical field of view. When images having parallax are provided for the left and right eyes, an upper limit of the magnification of the light beams is set in consideration of the distance between the left and right eyes to prevent cross-talk.

An optical deflection device for deflecting light by a mirror mounted on the tip of a rod-like torsion spring which oscillates at near resonance frequency. An optical deflection device which produces a large amplitude by exerting control to avoid variation in the natural oscillation frequency of the torsion spring (including mirror) regardless of temperature fluctuation.

Optical deflection device

The object is to provide an image viewing system that allows easy image viewing with reduced eyestrain, whether for wide-angle or enlarged viewing. The rotation of the viewer's head is detected by means of piezo-electric vibration gyroscopes,and,, and the coefficient for setting the amount of change in the camera system's image shooting direction with reference to the detected direction is changed in accordance with the focal length of the camera system's zoom lens systems. Moreover, the amount of change in the image shooting direction may be changed manually by means of sensitivity setting lever,mounted on HMD

Image viewing system and image display device

A scanning-type image viewing optical system has a light source for emitting luminous flux; a main scanning means for scanning luminous flux in a first direction; a sub-scanning means for scanning luminous flux in a second direction different from the first direction; and an eyepiece lens for directing luminous flux scanned by the two scanning means to the pupil of an observer, wherein the main scanning means has a conjugate relationship with the pupil position of the observer via the eyepiece lens, and when the pupil diameter, i.e., the luminous flux diameter of the incident luminous flux at the pupil position of the observer, is designated d and the main scan diameter, i.e., the luminous flux diameter exiting the main scanning means, is designated d', the conjugate magnification .beta. calculated by d/d' satisfies the conditional equation .beta..ltoreq.0.85.

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Itami, Japan

Yasushi Kobayashi