Hitachi, Ltd.

Hitachi Maxell, Limited

Hitachi Video Engineering, Incorporated

Hitachi Video Eng. Inc.

Atsuo Osawa

Hiroki Yoshikawa

Koji Hirata

Takahiko Yoshida

Nobuyuki Kaku

Shigeru Mori

Naoyuki Ogura

Kenji Ogiro

Masayuki Muranaka

Isao Yoshizaki

Takashi Sasaki

Atsushi Inoue

Michitaka Ohsawa

Takeshi Hoshino

Tetsu Ohishi

Hidekazu Takeda

Masaji Ishigaki

Kiyoshi Kano

Takeshi Minemoto

Yutaka Matsuda

Shinya Fujimori

Yoshihiro Fukagawa

Yoshimasa Yokoyama

Shinichi Goto

Kouhei Takita

Norio Yatsuda

Kunio Umehara

Kiyoshi Wada

Masahide Aoki

Masanori Kochi

Hideo Tanide

Hitoshi Takizawa

Shouzou Yokoo

Yutaka Matuda

A display device and operation method thereof for displaying images processed on an image processing apparatus on a horizontally installed, upward facing display screen with the operation method for said display device comprising; a step for specifying the number of screens for display on the display screen, a step for displaying image information on a screen with a predetermined image direction in said display device based on the specified number of screens, a step to change the established display direction, a step to display said screen based on instructions for changing the display direction; and further comprising a step to specify the number of screens for display on said display screen and the direction of said display screen, a step to display an image on the display screen based on the specified number of screens and specified direction of the display screen thus allowing an ideal screen to be provided on a single display device for a plurality of users by changing the direction of the screen along with the number of screens for display. A user's own screen currently in use, can further be changed to face other users thus permitting joint use of information shown on the display screen of the display device.

Display operation method to change the number of images to be displayed and to independently change image direction and rotation of each image

An image display device which is compact on the whole and low in cost, and which uses a plurality of projection lens systems each of which is constituted by five lens groups including a first aspherical lens group, a second aspherical lens group, a third biconvex lens group, a fourth aspherical lens group and a fifth aspherical lens group which are arranged in this order successively from a screen side, the third lens group having refractive power of not lower than 70% of the total power of the projection lens system, the respective peripheral shapes of the first and second aspherical lens groups being set to have a predetermined relation, a low-dispersion high-index glass material being used for a convex lens of a green projection lens system, a high-dispersion high-index glass material being used for convex lenses of blue and red projection lens systems.

Projection lens and image display device

A multi-display apparatus includes a plurality of rear projection-type display devices each in which projection light from image sources is projected through projection lenses onto a rear projection surface of a rear projection screen to form a picture image on a front viewing surface of the rear projection screen, the plurality of rear projection-type display devices being combined together in contiguous relation to one another to form a large screen. An overall front viewing surface of the large screen is formed into a concave surface curved both in a horizontal visibility angle direction and a vertical visibility angle direction. A light-absorbing portion is formed on the front viewing surface of the rear projection screen, and the light-absorbing portion absorbs projection light which passes through one rear projection screen, and is incident as external light on another rear projection screen, thereby preventing a picture image from being degraded.

Multi-display apparatus

To achieve an expansion of color reproducibility and an improvement in contrast ratio, color filters 8R, 8G and 8B formed in stripes are successively arranged on one surface of a front glass substrate 1, interposing a black matrixes 7 between them. Sustaining electrodes 6 are provided thereon and a dielectric layer 9 and a protecting layer 10 are provided. On a rear glass substrate 2, barrier ribs 3 are provided in the manner they face the respective black matrixes 7, and thus the spaces between the barrier ribs 3 facing the respective color filters 8R, 8G and 8B form cells. The cells are respectively provided with the sustaining electrodes 6 falling at right angles with the address electrodes 4, coated with fluorescent substances 5R, 5G and 5B corresponding to the respective colors, and also sealed to hold discharge gas therein. A wave band selecting filter 11 for screening the light emitted from the discharge gas in the respective cells is provided on the other surface of the front glass substrate 1.

Plasma display panel with optical filters

Projecting lens and image display device

A transmission screen for a rear projection type image display apparatus having at least one image generation source for displaying images, at least one projection lens for enlarging and projecting images displayed on the at least one image generation source onto a rear portion of the transmission screen for display. The transmission screen of the image display apparatus enables display of the images projected onto the transmission screen with a contrast of at least 70. Further, the transmission screen enables display with a field angle within a range of at least 72.degree. to less than 100.degree.. The transmission screen also includes a glossy light absorbing layer and a substantially smooth mirror surface at a light exit surface thereof.

Rear projection type image display apparatus and transmission type

A rear-projection screen for a rear-projection image display comprises a Fresnel lens sheet (2) and a lenticular lens sheet (3), or a Fresnel lens sheet (2), a lenticular lens sheet (3) and a light absorbing sheet (4). The entrance surface (21) of the Fresnel lens sheet (2) or the entrance surface (41) of the light absorbing sheet (4) is formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses. The thickness of the Fresnel lens sheet (2) is approximately equal to that of the lenticular lens sheet (3). The entrance surface (31) and the exit surface (32) of the lenticular lens sheet (3) are formed by contiguously and horizontally arranging a plurality of vertically elongate lenticular lenses. Particles of a light diffusing material, which is essential to the prior art rear-projection screen, are not necessarily dispersed in the base sheet (30) of the lenticular lens sheet (3). The rear-projection image display provided with this rear-projection screen has satisfactory focusing characteristics and enhanced vertical directional characteristics and is capable of displaying an image in high brightness and high contrast.

Rear-projection screen and a rear projection image display employing the

A rear-projection screen for a rear-projection image display apparatus comprises a Fresnel lens sheet, a first lenticular lens sheet, and a second lenticular lens sheet or a Fresnel lens sheet, first and second lenticular lens sheets and a light absorbing sheet. A light entrance surface of the first lenticular lens sheet or a light exit surface thereof, or both of these surfaces are formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses. A thickness of the first lenticular lens sheet is selected to be the thinner than thicknesses of the Fresnel lens sheet, the second lenticular lens sheet, and the light absorbing sheet. The entrance surface and the exit surface of the second lenticular lens sheet are formed by contiguously and horizontally arranging a plurality of vertically elongate lenticular lenses. Particles of a light diffusing material are not necessarily dispersed in the base sheet of the second lenticular lens sheet. The rear-projection image display apparatus provided with this rear-projection screen has satisfactory focusing characteristics and enhanced vertical directional characteristics and is capable of displaying an image in high brightness and high contrast.

Rear-projection type image display apparatus and rear-projection type

A rear-projection screen for a rear-projection image display comprising a Fresnel lens sheet (2) and a lenticular lens sheet (3), or a Fresnel lens sheet (2), a lenticular lens sheet (3) and a light absorbing sheet (4). The entrance surface (21) of the Fresnel lens sheet (2) or the entrance surface (41) of the light absorbing sheet (4) is formed by contiguously and vertically arranging a plurality of horizontally elongate lenticular lenses. The thickness of the Fresnel lens sheet (2) is approximately equal to that of the lenticular lens sheet (3). The entrance surface (31) and the exit surface (32) of the lenticular lens sheet (3) are formed by contiguously and horizontally arranging a plurality of vertically elongate lenticular lenses. Particles of a light diffusing material, which is essential to the prior art rear-projection screen, are not necessarily dispersed in the base sheet (30) of the lenticular lens sheet (3). The rear-projection image display provided with this rear-projection screen has satisfactory focusing characteristics and enhanced vertical directional characteristics and is capable of displaying an image in high brightness and high contrast.

A tape loading mechanism for a video cassette recording apparatus in which a magnetic tape held in the cassette is withdrawn therefrom by a tape loading arm and is wound around a rotary cylinder. During this time, the cassette is fixed on the upper surface of a chassis having a cam bore, which is driven by a rotary arm in which a pin inserted in the cam bore is set up. This cam bore is provided with a first cam surface having a radius of curvature equal to that of a locus of a turning movement of the pin, a second cam surface formed continuously from the first cam surface and having a radius of curvature different from that of a locus of a turning movement of the pin, and a third cam surface formed continuously from the second cam surface and having a radius of curvature equal to that of a locus of a turning movement of the pin. Accordingly, the movement of the cassette is started at a predetermined period of time after the movement of the tape loading arm has been started, and it is completed before the movement of the tape loading arm has been completed.

Magnetic tape loading mechanism and method

A tape guide moving mechanism for use with magnetic tape reproducing apparatus having a cylindrical cylinder mounted with a rotatable magnetic head thereon, and adapted to draw a magnetic tape from a tape cartridge and wound the magnetic tape on the cylindrical outer surface of said cylinder, comprising: a plurality of tape guides having a first group of tape guides and a second group of tape guides, drawing out the magnetic tape in a direction parallel to a plane perpendicular to the rotating axes of said supply and take-up reels; and drawing out the magnetic tape through said second position in slanting relation to a plane perpendicular to the rotating axis of said supply and take-up reel and winding said thus drawn magnetic tape around said cylinder in slanting relation to the plane section thereof.

Tape guide moving mechanism for magnetic record reproducing apparatus

A locking device for a cover of a magnetic tape cartridge for locking a pivotable cover for covering magnetic tape inlet and outlet ports of the magnetic tape cartridge, including a projection formed on an arm for pivotally supporting the pivotable cover which is engageable with an engaging claw section of a locking member which further includes an operation section and a resilient section. The locking member is pivotally supported on a magnetic tape cartridge case and urged by the biasing force of the resilient section to bring the engaging claw section into engagement with the projection. The operation section of the locking member is located in a position in which it is capable of cooperating with an unlocking pin moved from three directions, to thereby give latitude to the process for loading a magnetic tape cartridge on a magnetic recording and reproducing apparatus.

Locking device for a cover of magnetic tape cartridge

A magnetic recording/reproducing apparatus for recording onto or reproducing from a magnetic tape housed in a cassette by using a rotary magnetic head having a tape withdrawal arrangement for winding a portion of the tape between the two reels in the cassette around the rotary magnetic head by a predetermined angle. A tape drive feed the magnetic tape at a constant speed, with a reel drive being provided for driving either one of the two reels so as to take up the magnetic tape in the reel driven by the reel drive, and with brake arrangement for braking the rotation of the reels. A ring-shaped cam operating member is provided in the outer peripheral surface or the inner peripheral surface thereof with cam surfaces each for effecting the operation of the respective elements in response to the mode of operation of the magnetic recording/reproducing apparatus. The selective operation is specifically determined by the rotational position of the ring-shaped cam operating member, and the rotational position is varied in response to the mode of operation. A detector is provided for detecting the rotational positions in the ring-shaped cam operating member.

Magnetic recording/reproducing apparatus for recording onto or

A rotary cylinder device for helical scan type magnetic recording/reproducing apparatus including a rotary cylinder having an axis of rotation arranged in opposition a stationary cylinder in the direction of the axis of rotation with a small gap therebetween. The rotary cylinder has an end surface facing the stationary cylinder and an outer peripheral surface, recesses formed in the end surface and opening in the outer peripheral surface so as to extend therefrom radially inwardly over a small distance. Each of the recesses has a leading end wall and a trailing end wall, as viewed in the direction of rotation of the rotary cylinder. Magnetic heads are fixed to the rotary cylinder and are positioned in the recesses and have outer extremities projecting beyond the outer peripheral surface of the rotary cylinder. The distance between the leading end wall and the trailing end wall of each recess progressively decreases towards the axis of rotation of the rotary cylinder so that the distance is greatest at the outer end of the recess adjacent the magnetic head and the smallest at the inner end of the recess remote from the magnetic head.

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Yokohama, Japan

Atsuo Osawa