Abstract: A projection display is capable of suppressing both the trapezoidal distortion of an enlarged image projected on a screen by oblique projection and aberrations resulting from oblique projection and includes a projection optical system provided with lenses that can be easily manufactured and assembled. The projection optical system for obliquely projecting an image formed by a display device on the screen includes a free curved lens having a rotationally asymmetric free curved surface. The free curved lens has fringing parts having outlines of a shape coinciding with an arc of a circle having the center on the optical axis of the free curved lens.

Abstract: A projection image display device is disclosed in which a trapezoidal distortion and/or aberration are restrained when an image is enlarged and projected obliquely onto a screen. An image generator is connected to an optical system base in such a manner that at least an inclination thereof (on an axis parallel to X axis) with respect to a vertical line and a distance thereof in forward and backward direction (Z axis direction) can be adjusted by an adjusting mechanism. Further, a projecting lens 2 as a first optical system and a free-form curved surface mirror as a second optical system are fixed to the optical system base. The free-form curved surface mirror is rotatable (on an rotary axis parallel to X axis) with respect to the vertical line at a substantial center of the free-form curved surface mirror.

Abstract: A projection image display device is disclosed in which a trapezoidal distortion and/or aberration are restrained when an image is enlarged and projected obliquely onto a screen. An image generator is connected to an optical system base in such a manner that at least an inclination thereof (on an axis parallel to X axis) with respect to a vertical line and a distance thereof in forward and backward direction (Z axis direction) can be adjusted by an adjusting mechanism. Further, a projecting lens 2 as a first optical system and a free-form curved surface mirror as a second optical system are fixed to the optical system base. The free-form curved surface mirror is rotatable (on an rotary axis parallel to X axis) with respect to the vertical line at a substantial center of the free-form curved surface mirror.

Abstract: An image that has been displayed on the display screen of an image generator is first passed through a projection lens section consisting of a front group and a rear group. Next after being reflected on the reflecting surface of a free-form surface mirror, the image is further reflected by a planar reflecting mirror and then obliquely projected from the lower section of a projection screen onto the screen. The front group of the projection lens section is provided for enlarging the image. In order to correct aberration due to oblique projection onto the projection screen, the rear group uses a free-form surface lens that forms a concave shape with respect to the exit side of light from the lens. The free-form surface mirror corrects trapezoidal distortion due to oblique projection onto the projection screen.

Abstract: An image projection apparatus (i.e., a projector), having a light source unit 200, being disposed within an inside of an about box-like housing 100, a light modulation unit 300, and a projection optic unit 400 for projecting the image light from the light modulation unit, enlargedly, wherein the projection optic unit has a lens group including a plural number of lens elements, which are disposed symmetrically with respect to an optical axis, and a lens element having a configuration asymmetric with respect to the optical axis, sequentially, directing from the image display element towards projection of the light.

Abstract: A screen is hung from a screen frame with hanging members bonded to the upper side of a front sheet. Supporting members are disposed on the lower side of the front sheet and, by mounting a Fresnel lens sheet on the supporting members, a tension is given by its weight to the front sheet in the vertical direction. Further, a tension in the horizontal direction is given to the front sheet. Long holes are so formed in the hanging members that the hanging members on the right and left sides of the screen by expansion or contraction of the screen are made greater in the extent of shifting in the horizontal direction than the hanging member in the central part.

Abstract: A projection lens apparatus includes a plurality of lenses, for enlarging and projecting, onto a screen, an original image displayed on an image generation source. The plurality of lenses are arranged, beginning with the lens nearest the screen, as first to sixth lens groups. The fourth lens group includes one meniscus lens that has a positive refracting power and has a concave lens surface directed toward the screen. The concave lens surface of the meniscus lens included in the fourth group lens has a curvature in the vicinity of an outer portion of the concave lens surface that is smaller than a curvature in a predetermined area of the concave lens surface defined between a light axis of the concave lens surface of the meniscus lens and the smaller curvature of the concave lens surface in the vicinity of the outer portion of the concave lens surface.

Abstract: An associative memory carries out a search operation in plural fields. The search data 3-1 through 3-r in fields, r in number, are supplied to the primary associative memories 20-1 through 20-r. The i-th primary associative memory 20-i carries out the search operation, produces the primary match line 17-1-1 through 17-m-r, and maintains the state of logical AND operation by every word of the primary match line 17-j-1 through 17-j-r, the secondary match line 18-j-1 through 18-j-r, and memory means m-j when primary search enabling signal 10-i is in a valid state. Supplied with the states maintained in the stored information in each word and memory means 43, the primary associative memory 20-i provides the intermediate data 93-i. The secondary associative memory 21-i with words, m in number, searches for the intermediate data 93-i and produces the secondary match line 18-i-1 through 18-i-m when secondary search enabling signal 11-I is in a valid state.

Abstract: When one or more storage data are coincident with single search data (12), an associative memory (1) carries out logical sum for all of storage data with a valid state for storage data as true. The result of logical sum is used as matched data logical-OR information. In a primary searching operation, the associative memory (1) is supplied with the search data (12) to provide the matched data logical-OR information on matched data logical-OR lines. Then, the associative memory (1) carries out a secondary searching operation supplied as search data with the matched data logical-OR information obtained by all of storage data coincident upon the primary searching operation. Only a match line (5) coincident with the matched data logical-OR information is selected as the secondary search result. The associative memory is used in a network router to calculate an optimum memory address signal (403) by encoding the selected match line (5).

Abstract: An associative memory 4 for primary searching operation of an associative memory 23 supplies a valid state to a primary match line 13 corresponding to storage data coincident with search data 10 taking mask information into account, and supplies a value obtained from a result of a logical sum operation (an OR operation), with a valid state for the storage data as true, of all said coincident storage data to a counting means 25 as intermediate data 15. The counting means 25 supplies a result of an operation to the intermediate data 15 for counting the number of bits in an invalid state for the storage data to an associative memory 3 for secondary searching operations as secondary search data 19. Among secondary storage data obtained by carrying out said operation to said storage data, the associative memory 3 for secondary searching operation supplies a result of carrying out the searching operation of the secondary search data 19 to a secondary match line 21.

Abstract: An inexpensive projection lens unit in a rear projection type image display system, having a short focal distance (wide angle of viewing field), high focus and high contrast, and as well, including a power lens made of a glass material having a high refractive index in a range from 1.63 to 1.70 and an Abbe's number of not less than 50 with an optimized incident and emergent configuration in order to satisfactorily correct aberration with a enhanced focusing performance even with a shortened focal distance. Further, the power lens having a high refractive index can exhibit a high power, and accordingly, can carry out satisfactory aberration correction by optimizing the aspheric degree of a plastic lens even though the length of back focus is increased for enhancing the contrast.

Abstract: An associative memory 4 for primary searching operation of an associative memory 23 supplies a valid state to a primary match line 13 corresponding to storage data coincident with search data 10 taking mask information into account, and supplies a value obtained from a result of a logical sum operation (an OR operation), with a valid state for the storage data as true, of all said coincident storage data to a counting means 25 as intermediate data 15. The counting means 25 supplies a result of an operation to the intermediate data 15 for counting the number of bits in an invalid state for the storage data to an associative memory 3 for secondary searching operations as secondary search data 19. Among secondary storage data obtained by carrying out said operation to said storage data, the associative memory 3 for secondary searching operation supplies a result of carrying out the searching operation of the secondary search data 19 to a secondary match line 21.

Abstract: A screen is hung from a screen frame with hanging members bonded to the upper side of a front sheet. Supporting members are disposed on the lower side of the front sheet and, by mounting a Fresnel lens sheet on the supporting members, a tension is given by its weight to the front sheet in the vertical direction. Further, a tension in the horizontal direction is given to the front sheet. Long holes are so formed in the hanging members that the hanging members on the right and left sides of the screen by expansion or contraction of the screen are made greater in the extent of shifting in the horizontal direction than the hanging member in the central part.

Abstract: A projection display is capable of suppressing both the trapezoidal distortion of an enlarged image projected on a screen by oblique projection and aberrations resulting from oblique projection and includes a projection optical system provided with lenses that can be easily manufactured and assembled. The projection optical system for obliquely projecting an image formed by a display device on the screen includes a free curved lens having a rotationally asymmetric free curved surface. The free curved lens has fringing parts having outlines of a shape coinciding with an arc of a circle having the center on the optical axis of the free curved lens.

Abstract: When one or more storage data are coincident with single search data (12), an associative memory (1) carries out logical sum for all of storage data with a valid state for storage data as true. The result of logical sum is used as matched data logical-OR information. In a primary searching operation, the associative memory (1) is supplied with the search data (12) to provide the matched data logical-OR information on matched data logical-OR lines. Then, the associative memory (1) carries out a secondary searching operation supplied as search data with the matched data logical-OR information obtained by all of storage data coincident upon the primary searching operation. Only a match line (5) coincident with the matched data logical-OR information is selected as the secondary search result. The associative memory is used in a network router to calculate an optimum memory address signal (403) by encoding the selected match line (5).

Abstract: An inexpensive projection lens unit in a rear projection type image display system, having a short focal distance (wide angle of viewing field), high focus and high contrast, and as well, including a power lens made of a glass material having a high refractive index in a range from 1.63 to 1.70 and an Abbe's number of not less than 50 with an optimized incident and emergent configuration in order to satisfactorily correct aberration with a enhanced focusing performance even with a shortened focal distance. Further, the power lens having a high refractive index can exhibit a high power, and accordingly, can carry out satisfactory aberration correction by optimizing the aspheric degree of a plastic lens even though the length of back focus is increased for enhancing the contrast.

Abstract: An image that has been displayed on the display screen of an image generator 1 is first passed through a projection lens section 2 consisting of a front group and a rear group. Next after being reflected on the reflecting surface of a free-form surface mirror 5, the image is further reflected by a planar reflecting mirror 4 and then obliquely projected from the lower section of a projection screen 3 onto the screen 3. The front group of the projection lens section 2 is provided for enlarging the image. In order to correct aberration due to oblique projection onto the projection screen, the rear group uses a free-form surface lens that forms a concave shape with respect to the exit side of light from the lens. The free-form surface mirror 5 corrects trapezoidal distortion due to oblique projection onto the projection screen.

Abstract: This invention needs no priority encoder to connect the plural number of associative memories. The primary searching associative memory 4 of the associative memory 204 produces the intermediate data 6 obtained after the logical sum operation for the coincident storage data in the confirmed valid state, taking the research data 2 and the mask information into account, into the intermediate data determination section 41 and the internal secondary searching associative memory 5. The intermediate data arithmetic section 42 produces the valid state to the valid search signal 45 corresponding to the storage data with the least number of bits in invalid state among the intermediate data 6 supplied from the first through p-th associative memory 204. The first through p-th secondary searching associative memory 5 carries out the search operation for the storage data with the corresponding intermediate data 6 as the search data, supplying the match line 3.

Abstract: An inexpensive projection lens unit in a rear projection type image display system, having a short focal distance (wide angle of viewing field), high focus and high contrast, and as well, including a power lens made of a glass material having a high refractive index in a range from 1.63 to 1.70 and an Abbe's number of not less than 50 with an optimized incident and emergent configuration in order to satisfactorily correct aberration with a enhanced focusing performance even with a shortened focal distance. Further, the power lens having a high refractive index can exhibit a high power, and accordingly, can carry out satisfactory aberration correction by optimizing the aspheric degree of a plastic lens even though the length of back focus is increased for enhancing the contrast.

Abstract: The invention provides a projection image display device in which a trapezoidal distortion and/or aberration are restrained when an image is enlarged and projected obliquely onto a screen and an assembling and adjusting are easily done, and a projection optical unit usable for the device. An image generator is connected to an optical system base in such a manner that at least an inclination thereof (on an axis parallel to X axis) with respect to a vertical line and a distance thereof in forward and backward direction (Z axis direction) can be adjusted by an adjusting mechanism. Further, a projecting lens 2 as a first optical system and a free-form curved surface mirror as a second optical system are fixed to the optical system base. The free-form curved surface mirror is rotatable (on an rotary axis parallel to X axis) with respect to the vertical line at a substantial center of the free-form curved surface mirror.