1. A steam vacuum cleaner, comprising:
a base assembly;
a main assembly including a steam generator; and
a neck assembly for connecting the main assembly rotatable with respect to the base assembly,
wherein the main assembly is provided with an exhaust duct to exhaust discharged air from the base assembly to outside via the neck assembly, the exhaust duct comprising an exhaust groove formed at the main assembly, a filter mounted to the exhaust groove, and a filter cover for openingclosing the exhaust groove.
2. The steam vacuum cleaner according to claim 1, wherein the filter cover is comprised of a cover plate provided with an exhaust hole, a detachable projection formed at the upper and lower faces of the cover plate to be lodged into a groove formed at the upper and lower faces inside the exhaust groove, and an operation unit for operating the detachable projection.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A zoom lens for photographing an image of an object, comprising:
at least a first lens group having a positive refracting power;
at least a second lens group placed on an image side of the first lens group having a negative refracting power; and
at least a third lens group placed on an image side of the second lens group having a positive refracting power, the third lens group having at least a positive lens, when changing magnification from a wide-angle end toward a telephoto end, a spacing between the first lens group and the second lens group increasing, and a spacing between the second lens group and the third lens group decreasing,
on an orthogonal two-dimensional coordinate plane taking a partial dispersion ratio \u03b8g,F defined by the formula: \u03b8g,F=(ng\u2212nF)(nF\u2212nc), whereat ng is a refractive i to a g line, nF is a refractive index to an F line, and nc is a refractive index to a c line, on the vertical axis, and taking an Abbe number \u03bdd on the horizontal axis, when a straight line connecting a coordinate point (\u03bdd=60.49, \u03b8g,F=0.5432) of a standard glass type K7 and a coordinate point (\u03bdd=36.26, \u03b8g,F=0.5830) of a standard glass type F2 being defined as a standard line, and a deviation of the partial dispersion ratio \u03b8g,F of the glass type from the standard line on the two-dimensional coordinate plane being defined as an anomalous dispersiveness \u0394\u03b8g,F of the glass type, a refractive index Nd and the Abbe number \u03bdd and the anomalous dispersiveness \u0394\u03b8g,F of the positive lens of the third lens group satisfying the following condition (1) through the condition (3)
Nd>1.58\u2003\u2003(1)
\u03bdd>60.0\u2003\u2003(2)
0.05>\u0394\u03b8g,F>0.003.\u2003\u2003(3)
2. A zoom lens according to claim 1, further comprising an aperture stop between the second lens group and the third lens group, wherein at least the first lens group and the third lens group move toward the object side when changing magnification from the wide-angle end toward the telephoto end, in such a manner that the spacing between the first lens group and the second lens group increases and the spacing between the second lens group and the third lens group decreases.
3. A zoom lens according to claim 1, further comprising a fourth lens group on an image side of the third lens group, wherein the spacing between the first lens group and the second lens group increases, the spacing between the second lens group and the third lens group decreases, and the spacing between the third lens group and the fourth lens group varies, when changing magnification from the wide-angle end toward the telephoto end.
4. A zoom lens according to claim 3, further comprising an aperture stop between the second lens group and the third lens group, wherein at least the first lens group and the third lens group move toward the object side when changing magnification from the wide-angle end toward the telephoto end, in such a manner that the spacing between the first lens group and the second lens group increases, the spacing between the second lens group and the third lens group decreases, and the spacing between the third lens group and the fourth lens group increases.
5. A zoom lens according to claim 1, wherein one piece of positive lens of the third lens group satisfies the condition (1) through the condition (3), and a focal length fap of the positive lens and a focal length fw of the whole system at the wide-angle end satisfy the following condition (4)
1.0>fapfw<2.5.\u2003\u2003(4)
6. A zoom lens according to claim 1, wherein the third lens group has at least two pieces of positive lenses and one piece of negative lens, a first piece of the positive lenses satisfies the condition (1) through the condition (3), and a second piece of the positive lenses has an aspherical surface.
7. A zoom lens according to claim 6, wherein a negative lens with a strong concave surface facing toward the image side is disposed on a most image side of the third lens group, and a curvature radius r3R of the lens surface on the image side of the negative lens and the focal length fw of the whole system at the wide-angle end satisfy the following condition (5)
0.8<|r3R |fw<1.6.\u2003\u2003(5)
8. A zoom lens according to claim 1, wherein a whole movement X1 of the first lens group when changing magnification from the wide-angle end toward the telephoto end and a focal length fT of the whole system at the telephoto end satisfy the following condition (6)
0.20<X1fT<0.70.\u2003\u2003(6)
9. A zoom lens according to claim 1, wherein a whole movement X3 of the third lens group when changing magnification from the wide-angle end toward the telephoto end and the focal length fT of the whole system at the telephoto end satisfy the following condition (7)
0.15<X3fT<0.40.\u2003\u2003(7)
10. A zoom lens according to claim 1, wherein a focal length f2 of the second lens group and a focal length f3 of the third lens group satisfy the following condition (8)
0.45<|f2|f3<0.85.\u2003\u2003(8)
11. A zoom lens according to claim 1, wherein a focal length f1 of the first lens group and the focal length fw of the whole system at the wide-angle end satisfy the following condition (9)
5.0<f1fw<11.0.\u2003\u2003(9)
12. An imaging device comprising a zoom lens according to claim 1, as a photographing zoom lens.
13. An imaging device according to claim 12, wherein an object image by the zoom lens is formed on a light-receiving surface of a color imaging element.
14. An imaging device according to claim 13, wherein the imaging element has over 5 to 8 million pixels.
15. A personal digital assistant, comprising the imaging device according to claim 12.