摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.