Abstract: An image display apparatus which enables observation of a clear image at a wide field angle and which is extremely small in size and light in weight. The apparatus includes an image display device (6) for displaying an image, and an ocular optical system (7) for leading the image displayed by the image display device (6) to an observer's eyeball (1). The ocular optical system (7) has a first surface 3, a second surface 4, and a third surface 5. A space formed by the three surfaces is filled with a transparent medium having a refractive index larger than 1. Light rays emitted from the image display device (6) pass through the third surface (5) and are internally reflected by the first surface (3) and further internally reflected by the second surface (4), which is decentered and has positive power. The reflected light rays pass through the first surface (3) and are led to the observer's eyeball (1). The angle .theta..sub.

Abstract: An image display apparatus which enables observation of a clear image at a wide field angle, and which is extremely small in size and light in weight and hence unlikely to cause the observer to be fatigued. The image display apparatus has an image display device (7) and an ocular optical system for projecting the image of the image display device and leading the projected image to an observer's eyeball (1). The ocular optical system has, in the order of backward ray tracing, a first surface (3) which is a refracting surface, a second surface (4) which is a decentered reflecting surface of positive power, a third surface (5) which is a decentered reflecting surface, and a fourth surface (6) which is a refracting surface. At least two of the four surfaces have a finite curvature radius. A space formed by the first to fourth surfaces (3 to 6) is filled with a medium having a refractive index larger than 1.

Abstract: An image display apparatus which enables observation of a clear image at a wide field angle with substantially no reduction in the brightness of the observation image, and which is extremely small in size and light in weight and hence unlikely to cause the observer to be fatigued. The image display apparatus includes an image display device (6) for displaying an image, and an ocular optical system (7) for projecting the image displayed by the image display device (6) and for leading the projected image to an observer's eyeball (1). The ocular optical system (7) has at least three surfaces, and a space formed by the at least three surfaces is filled with a medium having a refractive index larger than 1.

Abstract: A compact and lightweight visual display apparatus which enables observation of an image that is clear throughout the image field at a field angle of 120.degree. when the user observes with both eyes, and which has a large exit pupil diameter. The visual display apparatus has a two-dimensional image display device (6) for displaying an image for observation, a relay optical system (5) for projecting a real image of the two-dimensional image display device (6) in the air, an ocular magnifier (3) for projecting the real image in the air as an enlarged image and for reflectively bending an optical axis, and a decentered correcting optical system (4) disposed between the relay optical system (5) and the ocular magnifier (3) and having surfaces (41 and 42) decentered with respect to each other.

Abstract: An image display apparatus, e.g. a head-mounted image display apparatus, which enables observation of a clear image at a wide field angle, and which is extremely small in size and light in weight and hence unlikely to cause the observer to be readily fatigued. The image display apparatus has an image display device (6) and an ocular optical system (7). The ocular optical system (7) has a first surface (3), a second surface (4) and a third surface (5), which are disposed in the mentioned order from the observer's eyeball (1) side. The space between the first and second surfaces (3 and 4) and the space between the second and third surfaces (4 and 5) are filled with a medium having a refractive index larger than 1. The first and second surfaces (3 and 4) have different curvatures. The second surface (4) is a reflecting or semitransparent surface which is decentered with respect to an observer's visual axis (2), and which has a concave surface directed toward the observer's eyeball (1).

Abstract: A head-mounted image display apparatus which uses two or more image display devices, and which is compact and lightweight and yet enables observation of a clear image over the entire observation image field at a wide field angle and high resolution. The image display apparatus includes two image display devices (5 and 6) and two ocular optical systems (3 and 4) for projecting, respectively, images formed by the two image display devices (5 and 6) as enlarged virtual images in front of one common eyeball (7) of an observer and for leading the projected images to the eyeball (7). When the two ocular optical systems are defined as a first ocular optical system (3) and a second ocular optical system (4) in order from the observer side, the first and second ocular optical systems (3 and 4) have concave mirrors (12 and 22), respectively. These reflecting surfaces are tilted or decentered with respect to an observer's visual axis (2).

Abstract: An image display apparatus which enables observation of a clear image at a wide field angle with substantially no reduction in the brightness of the observation image, and which is extremely small in size and light in weight. The image display apparatus has an image display device (7) and an ocular optical system (8) for projecting the image of the image display device (7) and leading the projected image to an observer's eyeball (1). The ocular optical system (8) has at least three optical surfaces, and a space formed by these surfaces is filled with a medium having a refractive index larger than 1. The three optical surfaces are defined as a first surface (3), a second surface (4), and a third surface (5), respectively, in the order in which light rays pass in backward ray tracing from the observer's eyeball (1) to the image display device (7).

Abstract: An image display apparatus which enables observation of a clear image at a wide field angle with substantially no reduction in the brightness of the image, and which is extremely small in size and light in weight and hence unlikely to cause the observer to be fatigued. The apparatus includes an image display device (6) and an ocular optical system (9) for leading an image of the display device (6) to an observer's eyeball (1). The ocular optical system (9) has a first optical element (7) and a second optical element (8). The first optical element (7) has three surfaces, and a space formed by the surfaces is filled with a medium having a refractive index larger than 1.

Abstract: A pin contact of a connector and a method of fabricating the pin contact which enables a substantial decrease of manufacturing cost, and smooth installation of the pin connector without a change in the pitch of arrangement at the time of press-fitting into a pin housing. A flat metal sheet undergoes blanking and pressing to form a narrow piece including a strip portion of decreased area of a fracture. Then an approximately L-shaped connecting portion is bent at right angles to raise the narrow piece sideways. Thereafter the strip portion of the narrow piece is pressed along the direction of rising, to thereby form an approximately cylindrical contact section. A raised piece at the rear of the contact section is provided with a locking section which faces approximately at right angles with the direction of arrangement.

Abstract: A pin contact of a connector and a method of fabricating the pin contact which enables a substantial decrease of manufacturing cost, and smooth installation of the pin connector without a change in the pitch of arrangement at the time of press-fitting into a pin housing. A flat metal sheet undergoes blanking and pressing to form a narrow piece including a strip portion of decreased area of a fracture. Then an approximately L-shaped connecting portion is bent at right angles to raise the narrow piece sideways. Thereafter the strip portion of the narrow piece is pressed along the direction of rising, to thereby form an approximately cylindrical contact section. A raised piece at the rear of the contact section is provided with a locking section which faces approximately at right angles with the direction of arrangement.

Abstract: An image display apparatus, e.g. a head-mounted image display apparatus, which is capable of satisfactorily correcting field curvature and other aberrations in an optical system simultaneously, and which enables even an image of high resolution to be sufficiently clearly observed, without forming an intermediate image. The apparatus has an image display device (6) for displaying an image, and an optical system for projecting an image formed by the image display device (6) without forming an intermediate image and for leading the projected image to an observer's eyeball (1). The optical system includes at least one concave mirror (4) having a rotationally asymmetric reflecting surface which is concave toward the observer's eyeball and decentered with respect to an optical axis, and at least one optical element (9) of positive refractive power which is disposed between the concave mirror (4) and the image display device (6).

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: The present invention is an optical apparatus, e.g. an image display apparatus, which enables observation of a clear image at a wide field angle with substantially no reduction in the brightness of the observation image, and which is extremely small in size and light in weight and hence unlikely to cause the observer to be fatigued. The optical apparatus has an image display device (6), and an ocular optical system (7) for leading an image of the image display device (6) to an observer's eyeball (1). The ocular optical system (7) includes, in order from the image side, a third surface (5) which forms an entrance surface, a first surface (3) which forms both a reflecting surface and an exit surface, and a second surface (4) which forms a reflecting surface. The first to third surfaces (3 to 5) are integrally formed with a medium put therebetween which has a refractive index larger than 1.

Abstract: An image display apparatus which enables observation of a clear image at a wide field angle with substantially no reduction in the brightness of the observation image, and which is extremely small in size and light in weight and hence unlikely to cause the observer to be fatigued. The image display apparatus includes an image display device and an ocular optical system for projecting an image formed by the image display device and for leading the projected image to an observer's eyeball. The ocular optical system (3) has three surfaces, and a space formed by the three surfaces is filled with a medium having a refractive index larger than 1.

Abstract: A device-isolating trench having a taper at its upper portion is formed in a silicon semiconductor substrate. Then, a silicon oxide film is formed on the inner wall of the trench and the surface of the semiconductor substrate near the trench by an oxidizing method, and polycrystalline silicon is buried in the trench.

Abstract: A perforator has a rotary drum. A plurality of die sets are arranged at regular intervals around a peripheral surface of the drum and circulates along with the peripheral surface. Each of the die sets has a pair of die and punch. The die is secured to a die holder which is mounted to the peripheral surface, and the punch is secured to a punch holder which is linearly movable in a direction perpendicular to the peripheral surface between a punch position where the punch is fitted in the die and a retracted position where the punch is retracted away from the die. The sheet material is brought into contact with the peripheral surface within a predetermined range, and conveyed on the peripheral surface in the same direction at the same speed as the die sets. An annular punch drive cam disposed surrounding the peripheral surface drives the punch holder to move between the punch position and the retracted position.

Abstract: A carrier for an electrostatic latent-image developer, comprising a core material having thereon a coating layer comprising a resin and fine electroconductive particles, the resin having a work function of 4.5 eV or lower. An electrostatic latent-image developer comprising the carrier and a toner and an image forming process are also disclosed. The carrier is capable of maintaining a high build-up speed of electrification and a proper electrification level even when a charge control agent is omitted or used in a slight amount or when the addition amount of an additive such as silica and titanium oxide is reduced so as to prevent carrier fouling with a charge control agent or an external additive and to inhibit a decrease in developer life.

Abstract: A cassette for containing photographic film has a spool which is provided with retaining claws for retaining a trailer of the photographic film. A cassette port communicates the spool chamber to the outside. To load the photographic film into a cassette, a loading apparatus picks up the trailer with an inserter jig. The inserter jig is passed through the passage port, and is brought to the spool so as to insert the trailer into the cassette shell. The trailer is retained on the spool with the retaining claws. The inserter jig is then drawn out of the cassette shell. Then the spool is rotated in order to wind the photographic film around the spool, fully into the cassette shell. To remove exposed photographic film from such a cassette, the photographic film is drawn and unwound. A separator jig, as passed through the passage port, is brought to the spool. The trailer is released from retention on the retaining claws by use of the separator jig.

Abstract: A substantially transparent optical protection film formed on the surface of an information recording medium on which a dot pattern is printed for preventing printing quality from being degraded due to wear of the dot pattern. The protection film is formed to have such an optical thickness as to lower a predetermined amount of contrast of the dot pattern so that an image of dust or flaw on the protection film is defocused on an image pickup device, with the result that an adverse effect of the dust or flaw upon reading of the dot pattern can be eliminated.