Abstract: There is provided a projection system including a plurality of projectors that perform edge blending, each of the plurality of projectors including: an image display element; a light blocking plate that reduces an amount of light in an edge overlapping portion of a light bundle; and an aperture diaphragm that changes an amount of light traveling-toward an object to be projected, wherein when a circle formed by an outermost perimeter of a light passing region obtained when the aperture diaphragm is completely opened is defined as a reference circle, the aperture diaphragm partially covers the inside of the reference circle such that an outline of the reference circle is divided into three or more sections in a state where the aperture diaphragm is narrowed to make an area of the light passing region inside the reference circle half the reference circle.

Abstract: There is provided a projection system including a plurality of projectors that perform edge blending, each of the plurality of projectors including: an image display element; a light blocking plate that reduces an amount of light in an edge overlapping portion of a light bundle; and an aperture diaphragm that changes an amount of light traveling-toward an object to be projected, wherein when a circle formed by an outermost perimeter of a light passing region obtained when the aperture diaphragm is completely opened is defined as a reference circle, the aperture diaphragm partially covers the inside of the reference circle such that an outline of the reference circle is divided into three or more sections in a state where the aperture diaphragm is narrowed to make an area of the light passing region inside the reference circle half the reference circle.

Abstract: A wide angle lens, which forms an image on an image pickup device having a curved imaging surface, has a whole angle of view of 120° or more and comprises a first lens, a second lens and a third lens in this order from an object side. The first lens is a meniscus lens having a convex surface facing the object side, the second lens has a positive power and the third lens has a concave surface facing an image side. The first, the second and the third lenses respectively have at least one aspherical surface.

Abstract: A wide angle lens, which forms an image on an image pickup device having a curved imaging surface, has a whole angle of view of 120° or more and comprises a first lens, a second lens and a third lens in this order from an object side. The first lens is a meniscus lens having a convex surface facing the object side, the second lens has a positive power and the third lens has a concave surface facing an image side. The first, the second and the third lenses respectively have at least one aspherical surface.

Abstract: Provided is a low-cost and compact super-wide-angle anamorphic lens having small number of lenses and exhibiting excellent lens performance when the lens is used for an onboard camera, capturing of an unwanted portion is minimized. The super-wide-angle anamorphic lens has an angle of view of 180° or more in the horizontal direction, and includes a first lens having a negative power, a second lens having a negative power, a third lens having a positive power, a fourth lens having a positive power in that order from an object side. One of the aforementioned third lens and fourth lens is provided with at least one non-rotationally symmetric aspherical surface.

Abstract: A small-sized super wide-angle lens for a solid-state image sensor that is suitable for a digital input apparatus such as a monitoring camera and an onboard camera, which is excellent in terms of optical performance and is low in terms of cost. The super wide-angle lens includes, in order from an object side thereof: a first lens with a negative refractive power; a second lens with a negative refractive power; a third lens with a positive refractive power; and a fourth lens with a positive refractive power. The first lens is a meniscus lens including a convex surface facing the object side. Each of the second lens and the fourth lens includes at lest one rotational-asymmetric surface.

Abstract: Provided is a low-cost and compact super-wide-angle anamorphic lens having small number of lenses and exhibiting excellent lens performance when the lens is used for an onboard camera, capturing of an unwanted portion is minimized. The super-wide-angle anamorphic lens has an angle of view of 180° or more in the horizontal direction, and includes a first lens having a negative power, a second lens having a negative power, a third lens having a positive power, a fourth lens having a positive power in that order from an object side. One of the aforementioned third lens and fourth lens is provided with at least one non-rotationally symmetric aspherical surface.

Abstract: A wide-angle lens whose angle of view is more than 90 degrees and less than 120 degrees includes, in order from an object side thereof: a first lens having a negative power and including a spherical glass body; a second lens having a positive power and including an aspheric surface; and a third lens having a positive power and including an aspheric surface.

Abstract: A small-sized super wide-angle lens for a solid-state image sensor that is suitable for a digital input apparatus such as a monitoring camera and an onboard camera, which is excellent in terms of optical performance and is low in terms of cost. The super wide-angle lens includes, in order from an object side thereof: a first lens with a negative refractive power; a second lens with a negative refractive power; a third lens with a positive refractive power; and a fourth lens with a positive refractive power. The first lens is a meniscus lens including a convex surface facing the object side. Each of the second lens and the fourth lens includes at lest one rotational-asymmetric surface.

Abstract: An image pickup optical system for forming a light flux from an object into an optical image on an image pickup element, is provided with, in order from an object side thereof: a first lens with a negative power in a meniscus shape including a convex surface facing the object side; a second lens in a bioconcave shape; a third lens with a positive power including a convex surface facing an image surface side; and a fourth lens with a positive power including a convex surface facing the image surface side. The first lens and the third lens are glass lenses and the second lens and the fourth lens are plastic lenses.

Abstract: A wide-angle lens whose angle of view is more than 90 degrees and less than 120 degrees includes, in order from an object side thereof: a first lens having a negative power and including a spherical glass body; a second lens having a positive power and including an aspheric surface; and a third lens having a positive power and including an aspheric surface.

Abstract: An image display system includes a display device, an input section to which video signals of an interlace scanning system are inputted, a signal converter section which increases horizontal scanning lines of the inputted video signals in number by a factor of at least two, and which generates first and second fields, each of the fields including effective scanning lines used for displaying and ineffective scanning lines not used for displaying, with the effective and ineffective scanning lines being arranged alternately in each of the fields, and a display control section which controls the display device to display the first and second fields alternately. The display control section controls the display device such that positions of the effective scanning lines of the first fields correspond with those of the ineffective scanning lines of the second fields, and vice versa.

Abstract: A wide-angle lens system has, from the object side thereof: a first lens element having a negative optical power and having a meniscus shape convex to the object side; a second lens element having a biconcave shape; a third lens element having a biconvex shape; and a fourth lens element having a negative optical power and having a meniscus shape convex to the image side. Alternatively, a wide-angle lens system has, from the object side thereof: a first lens element having a negative optical power; a second lens element having a negative optical power; a third lens element having a positive optical power; and a fourth lens element having a positive optical power.

Abstract: A wide-angle lens system includes: from the object side, (1) a first lens element formed of glass having both surfaces thereof so formed as to be spherical, having a meniscus shape convex to the object side, and having a negative optical power; (2) a second lens element formed of plastic having a meniscus shape convex to the image side and having a positive optical power; (3) an aperture stop; and (4) a third lens element formed of plastic having a meniscus shape convex to the image side and having a positive optical power, and the wide-angle lens system includes three lens elements in total. This permits providing a low-cost, compact super-wide-angle lens system having a favorable optical performance.

Abstract: An image pickup optical system for forming a light flux from an object into an optical image on an image pickup element, is provided with, in order from an object side thereof: a first lens with a negative power in a meniscus shape including a convex surface facing the object side; a second lens in a bioconcave shape; a third lens with a positive power including a convex surface facing an image surface side; and a fourth lens with a positive power including a convex surface facing the image surface side. The first lens and the third lens are glass lenses and the second lens and the fourth lens are plastic lenses.

Abstract: A wide-angle lens system has, from the object side thereof: a first lens element having a negative optical power and having a meniscus shape convex to the object side; a second lens element having a biconcave shape; a third lens element having a biconvex shape; and a fourth lens element having a negative optical power and having a meniscus shape convex to the image side. Alternatively, a wide-angle lens system has, from the object side thereof: a first lens element having a negative optical power; a second lens element having a negative optical power; a third lens element having a positive optical power; and a fourth lens element having a positive optical power.

Abstract: A wide-angle lens system includes: from the object side, (1) a first lens element formed of glass having both surfaces thereof so formed as to be spherical, having a meniscus shape convex to the object side, and having a negative optical power; (2) a second lens element formed of plastic having a meniscus shape convex to the image side and having a positive optical power; (3) an aperture stop; and (4) a third lens element formed of plastic having a meniscus shape convex to the image side and having a positive optical power, and the wide-angle lens system includes three lens elements in total. This permits providing a low-cost, compact super-wide-angle lens system having a favorable optical performance.

Abstract: An image display system includes a memory for storing at least one scanning line of an inputted video signal of the interlace scanning system, and reading means for repeating to read the video signal of one scanning line from the memory at a speed which is n (n is an integer of 2 or more) times of the writing speed of the video signal for the memory for a horizontal scanning period which is 1/n of the writing period and to stop reading for a horizontal scanning period of the remaining (n?1)/n for each scanning line of one field which is sequentially inputted and reading each scanning line so that the continuous fields interpolate the period of stopping of reading from the memory each other.

Abstract: An image display system includes a memory for storing at least one scanning line of an inputted video signal of the interlace scanning system, and reading means for repeating to read the video signal of one scanning line from the memory at a speed which is n (n is an integer of 2 or more) times of the writing speed of the video signal for the memory for a horizontal scanning period which is 1/n of the writing period and to stop reading for a horizontal scanning period of the remaining (n−1)/n for each scanning line of one field which is sequentially inputted and reading each scanning line so that the continuous fields interpolate the period of stopping of reading from the memory each other.

Abstract: A zoom lens system has, from an enlargement side to a reduction side, a first lens unit having negative optical power and succeeding lens units including at least two lens units having positive optical power, wherein in zooming, all of lens units having negative optical power and included in entire zoom lens system is stationary in zooming.