Abstract: A pleated filter cartridge includes a pleated filter that includes a filter base having folds that repeatedly form mountains and valleys and having a tubular shape whose axial direction is a ridge line direction of the folds, and fixing members disposed on an upper bottom portion and a lower bottom portion of the pleated filter. The pleated filter includes a reinforcing structure for folds in the mountains which are projecting portions projecting toward the outside of the tubular shape. The reinforcing structure includes both a resin-reinforcing structure including, as a reinforcing body, a resin that covers a surface of the base in the folds or a resin that is allowed to permeate in the base in the folds, and a member-reinforcing structure in which reinforcing members provided separately from the filter base are disposed so as to extend along the folds.

Abstract: A ballast water treatment device includes a filtration device and an irradiation device that irradiates, with ultraviolet rays, filtered water that has been filtered. The filtration device is a device that removes 99.999% or more of L-size organisms having a minimum part size of 50 ?m or more, and 90% or more of S-size organisms having a minimum part size of 10 ?m or more and less than 50 ?m. The irradiation device is capable of sterilizing the filtered water at a flow rate of 250 m3/h and a power consumption of 13 kW to eliminate 90% of S-size organisms immediately after a sterilization treatment.

Abstract: A pleated filter includes a filter base having folds that repeatedly form mountains and valleys and having a cylindrical shape whose axial direction is a ridge line direction of the folds. The pleated filter includes, in a valley projecting to the inside of the cylindrical shape, a bonded reinforcing portion extending in the ridge line direction of the folds.

Abstract: A filtering device includes a pleated filter that includes a filter base having folds that repeatedly form mountains and valleys and having a cylindrical shape whose direction of an axis is a ridge line direction of the folds and in which the mountains are located outward in a radial direction, an untreated-water nozzle through which untreated water is ejected toward an outer circumferential surface of the pleated filter, a case that includes an outer tubular portion provided so as to surround the pleated filter and including a nozzle opening of the untreated-water nozzle therein, a filtered-water flow path that leads filtered water having passed through the pleated filter from the inside of the cylinder of the pleated filter to the outside of the case, and a discharge flow path through which discharge water that is not filtered by the pleated filter is discharged to the outside of the case. The pleated filter is configured to rotate in a direction about the axis.

Abstract: A pleated filter includes a filter base having folds that repeatedly form peak portions and valley portions and having a shape of a cylinder whose axial direction is a ridge line direction of the folds, and a reinforcing sheet disposed in a valley portion viewed from the inside of the shape of the cylinder. The reinforcing sheet includes a first reinforcing sheet located on a back side of a fold forming a projection toward the outer circumferential side of the shape of the cylinder and a second reinforcing sheet located in a spacing between adjacent folds forming projections toward the inner circumferential side of the shape of the cylinder. The first reinforcing sheet and the second reinforcing sheet are disposed apart from each other in a depth direction of pleats of the pleated filter.

Abstract: A pleated filter cartridge includes a pleated filter formed of a filter base having folds that repeatedly form peak portions and valley portions, the pleated filter having a shape of a cylinder whose axial direction is a ridge line direction of the folds, and lid portions disposed on an upper bottom and a lower bottom of the pleated filter. Reinforcing members whose top and bottom are fixed in the lid portions are provided in the valley portions viewed from the outside of the shape of the cylinder.

Abstract: A ballast water treatment apparatus includes a cylindrical pleated filter that is rotatably held about an axis of a cylinder, a driving mechanism that rotates the pleated filter, an untreated water nozzle that ejects untreated water toward an outer circumferential surface of the pleated filter, a case that is provided so as to surround the pleated filter and that includes an outer cylindrical portion including a nozzle opening of the untreated water nozzle therein, a filtered water flow path that guides filtered water that has permeated through the pleated filter from the inside of the cylinder of the pleated filter to the outside of the case, and a discharge flow path that discharges discharged water that has not been filtered by the pleated filter to the outside of the case. The ballast water treatment apparatus further includes a reverse cleaning mechanism that supplies cleaning water to the inside of the cylinder of the pleated filter through the filtered water flow path.

Abstract: The separation membrane for seawater desalination pretreatment is a separation membrane for seawater desalination pretreatment used in pretreatment for seawater desalination with a reverse osmosis membrane, wherein a standard flux A is 2 m/d or more, which is defined as a maximum value of a flux that can satisfy P2?1.5×P1 where P1 and P2 represent an average intermembrane differential pressure, and a saccharide removal rate B or a granular carbon removal rate C expressed by a prescribed equation is 0.3 or more, and desirably 0.5 or more.

Abstract: There is provided a water treatment apparatus, including: first membrane filtration means in which a filtration membrane having an average pore diameter of 1 ?m or more is used; second membrane filtration means for treating water filtered by the first membrane filtration means, by using a microfiltration membrane or ultrafiltration membrane; and reverse osmosis membrane filtration means for treating water filtered by the second membrane filtration means. In particular, there is provided a water treatment apparatus, wherein a hydrophobic polymer membrane that is not subjected to hydrophilicizing processing is used as the filtration membrane having an average pore diameter of 1 ?m or more. There is also provided a water treatment method that can be implemented by these water treatment apparatuses.

Abstract: There is provided a cleaning method for a hydrophobic filtration membrane used for membrane filtration of water to be treated such as seawater, discharged water and ballast water including a jelly-like suspended substance and clogged with the suspended substance in the water to be treated, the filtration membrane being brought into contact with limonene-containing water, or backwashing of the filtration membrane with a cleaning liquid being done, and then, a flow having air taken therein being applied onto a surface of the filtration membrane or a water stream from an eductor nozzle being sprayed onto the filtration membrane. There is also provided a membrane filtration apparatus capable of efficiently performing the above-mentioned cleaning method.

Abstract: An autofocus adapter is provided and includes an imaging adapter optical system placed on an optical axis of an imaging lens when the autofocus adapter is attached, and a focus state detection adapter optical system placed on an optical axis different from the optical axis of the imaging lens when the autofocus adapter is attached. The imaging adapter optical system has a light split prism for splitting subject light passing through the imaging lens into imaging subject light and the focus state detection subject light, a first lens group having a negative power as a whole and placed on the object side with respect to the light split prism, and a second lens group having a positive power as a whole and placed on the image side with respect to the light split prism. The focus state detection adapter optical system has a positive lens group having the same lens configuration as the second lens group in the imaging adapter optical system.

Abstract: The present invention provides a visible and infrared light photographing lens system. A color separating prism or the like divides an object light entering a photographing lens and then passing through a focus lens, into an object light in a visible light region and an object light in an infrared light region. A visible light image pickup element and an infrared light image pickup element are used to pick up images of the respective object lights. Further, a compensation lens can be used to adjust a position where an image of the object light in the infrared light region is formed. Consequently, visible light photographing and infrared light photographing can be simultaneously carried out by focusing on an object at the same distance.

Abstract: The auto focus system obtains focus information on a lens-interchangeable camera body of a TV camera and sends the focus information to a lens apparatus mounted on the camera body. The lens apparatus controls an auto focus based on the focus information. It is thereby possible to control the focus on adequate conditions according to optical specifications of the lens apparatus and so on.

Abstract: An autofocus adapter is provided and includes an imaging adapter optical system placed on an optical axis of an imaging lens when the autofocus adapter is attached, and a focus state detection adapter optical system placed on an optical axis different from the optical axis of the imaging lens when the autofocus adapter is attached. The imaging adapter optical system has a light split prism for splitting subject light passing through the imaging lens into imaging subject light and the focus state detection subject light, a first lens group having a negative power as a whole and placed on the object side with respect to the light split prism, and a second lens group having a positive power as a whole and placed on the image side with respect to the light split prism. The focus state detection adapter optical system has a positive lens group having the same lens configuration as the second lens group in the imaging adapter optical system.

Abstract: A focus detecting system for determining the focus state of an imaging lens, such as a camera lens, is disclosed. Object light not forming an image for image production is deflected along an optical axis through a relay lens to a focus state detection unit that includes image detecting elements with light receiving surfaces that are equidistant in front of and behind a position conjugate with a light receiving surface for image production. Either the relay lens or the focus state detection unit is moveable along the optical axis to vary how far the light receiving surfaces are out of focus. A diaphragm opening of the imaging lens determines if and by how much the relay lens and focus state detection unit are relatively moved. Evaluation values of the out of focus amount are compared in order to control focusing of the imaging lens.

Abstract: The focusing state determining adapter is detachably mounted between an interchangeable taking lens and a camera body in a camera system. The focusing state determining adapter includes a focus-imaging element and a beam splitter, which divides the subject light entering through the taking lens into light entering the focus-imaging element and light entering the camera body. The focusing state determining adapter determines the focusing state of the taking lens according to an image captured by the focus-imaging element.

Abstract: The present invention provides a visible and infrared light photographing lens system. A color separating prism or the like divides an object light entering a photographing lens and then passing through a focus lens, into an object light in a visible light region and an object light in an infrared light region. A visible light image pickup element and an infrared light image pickup element are used to pick up images of the respective object lights. Further, a compensation lens can be used to adjust a position where an image of the object light in the infrared light region is formed. Consequently, visible light photographing and infrared light photographing can be simultaneously carried out by focusing on an object at the same distance.

Abstract: A beam splitter (24)for splitting light in a wavelength range of about 500 nm to about 600 nm is arranged in a relay optical system of a taking lens (12). A green light beam reflected from the beam splitter (24) is directed through a relay lens (R3) to a focusing state determination imaging unit (26). The imaging unit (26) comprises three imaging elements (A, B, C) for capturing the directed green light beam to determine the focusing state. Thus, a device for determining the focusing state of the taking lens is provided, in which the green light beam is separated as an object light for determining the focusing state from the object light entering the taking lens (12), so that the focusing state can be determined with high accuracy on the basis of the high-frequency components of the image signal generated by capturing the green light beam by means of the imaging elements (A, B, C) having different optical path lengths.

Abstract: An autofocus system for an imaging device that includes an image detecting element for image production at a focused image plane of an adjustable focus imaging lens that also includes four image detecting elements for focus detection arranged in pairs that are equidistant in front of, and behind, planes that are conjugate with the focused image plane. One pair of image detecting elements for focus detection are farther than the other pair from the conjugate planes and may be used alone for focusing based on the stop value or focal length of the adjustable focus imaging lens. Alternatively, the other pair of image detecting elements may be used for more accurate focusing after the one pair of image detecting elements is used. The use of two pairs of image detecting elements at different distances from the focused image plane provides accurate focusing over a wide range of object distances.

Abstract: An imaging optical system includes at least one ghost image prevention element. Ghost images are prevented even when the imaging optical system includes an optical element that has at least one planar surface that is generally orthogonal to an optical axis of the imaging optical system, and is located in a light flux area with at least a central portion of the light flux area being generally parallel to the optical axis. The ghost image prevention element is especially useful in video cameras and digital cameras that use an image sensor having a planar surface that exhibits a high coefficient of reflection. The ghost image prevention element includes one planar surface, that is “tightly bound” to the planar surface of the optical element, and another surface that is curved so as to satisfy a given condition. The curved surface diffuses light that would otherwise contribute to a ghost image.