597results about How to "High zoom ratio" patented technology

A zoom lens comprising, in order from an object side thereof, a first lens group of positive refracting power, a second lens group of negative refracting power, an aperture stop, a third lens group of positive refracting power, a fourth lens group of negative refracting power, and a fifth lens group of positive refracting power. Upon zooming from the wide-angle end to the telephoto end, at least the first lens group and the aperture stop remain fixed in position, the second and third lens groups move in the optical axis direction, and the separation between each of the lens groups and the aperture stop changes. Upon focusing from a focusing-on-infinity state to a close-range-focusing state, the fourth lens group moves in the optical axis direction, with satisfaction of the following:

−0.36<f4/f1<−0.05  (1A),

where f1 and f4 are the focal lengths of the first and fourth lens groups, respectively.

Imaging lens device has a zoom lens system and an image sensor. The zoom lens system has a first reflecting surface, a first movable lens unit, an aperture stop, a second reflecting surface, a second movable lens unit. A first reflecting surface bends a first optical axis which is an incident optical axis of the zoom lens system 90 degrees into a second optical axis. A second reflecting surface bends the second optical axis 90 degrees into a third optical axis. The first optical axis, the second optical axis and the third optical axis are mutually perpendicular. The first movable lens unit and the aperture stop are disposed on the second optical axis. The second movable lens unit is disposed on the third optical axis. During zooming, the first and second reflecting surfaces and the aperture stop are stationary; the first and second movable lens units are moved, respectively.

A variable focal length lens system includes: a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; and a fourth lens group having a positive refractive power. As the lens position state changes from a wide-angle end state to a telephoto end state, at least each of the lens groups is mobile, the second lens group moves towards the image side and the third lens group moves towards the object side such that the gap between the first and the second lens group increases, and the gap between the second and the third lens group decreases, while the fourth lens group moves in the direction of the optical axis so as to compensate for changes in the position of the image plane which accompany movements of each of the lens group.

The present invention provides a compact, high-performance, and easy-to-manufacture taking optical system that offers an extremely high zoom ratio. The taking optical system includes, from the subject side, a first lens group having a positive optical power, a second lens group having a negative optical power, a third lens group having a positive optical power, and a fourth lens group having a positive optical power. The taking optical system achieves zooming by the movements of the first to fourth lens groups and focusing by the movement of the fourth lens group. The taking optical system fulfills the following conditions: 0.05≦f3/f4≦0.95 and 7.0≦f1/fw≦20.0, where f1, f3, and f4 represent the focal lengths of the first, third, and fourth lens groups, respectively, and fw represents the focal length of the entire taking optical system at the wide-angle end thereof.

The system disclosed herein seeks to solve the problem of unnatural, dizzy camera motion when moving a camera between two preset positions, e.g., head and shoulder shots of two videoconference participants. Particularly, the system described herein attempts to mimic the camera movement that a professional camera operator would use in a professional video production. A preferred method of moving the camera between two positions is to first zoom out, away from the first position, pan across to the next position, then zoom in. This gives viewers of the camera content an idea of the spatial relationship between the two camera positions and also avoids the aesthetically undesirable effect of panning through irrelevant visual background at high zoom ratios. Disclosed herein is a technique of producing this desired behavior in the context of an automatically or semi-automatically controlled video camera, such as those used in conjunction with videoconferencing equipment.

Disclosed are a zoom lens and an imaging apparatus having a high zoom ratio, a small total length, and a small overall size. A zoom lens includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power which are arranged in this order from an object side. A gap between the lens groups is changed to change power. The zoom lens satisfies the following Condition expression 1: 0.05<|f4|/ft<0.25   [Condition expression 1] (where ft indicates the focal length of the entire system at a telephoto end and f4 indicates the focal length of the fourth lens group).

A zoom lens system includes a front lens group and a rear lens group arranged from an object side to an image side in that order. The front lens group includes a plurality of lens units, and during zooming from a wide angle end to a telephoto end, imaging magnification is increased by changing spaces between the plurality of lens units. The rear lens group with positive optical power as a whole includes a lens unit IS with negative optical power being movable so as to have a component in a direction perpendicular to an optical axis, and a lens component RB2 with positive optical power disposed on the image side with respect to the lens unit IS. A space between the lens unit IS and the lens component RB2 is changed during zooming. The following condition is established to satisfy:

0.05<|fis|/ft<0.25,

wherein (fis) denotes a focal distance of the lens unit IS, and (ft) denotes a focal distance at the telephoto end of the zooming lens system.

A video camera includes an LCD monitor. On the LCD monitor, an object scene image belonging to a camera-shake correction area out of the object scene image captured by an imaging surface is displayed. A CPU determines whether or not a movement of the object scene image captured by the imaging surface satisfies a pan/tilt condition or a camera-shake condition referring to a threshold value. The threshold value is set to a large numerical value as a zoom magnification is high. A camera-shake condition determining process is started in place of a pan/tilt condition determining process when the pan/tilt condition is satisfied. Also, the pan/tilt condition determining process is started in place of the camera-shake condition determining process when the camera-shake condition is satisfied. In addition, the camera-shake correction area is moved in such a direction as to cancel the movement of the object scene image captured by the imaging surface when the pan/tilt condition is not satisfied.

The zoom lens includes, in order from an object side to an image side, a first lens unit having a negative refractive power, a rear unit including one or more lens units, a distance between every adjacent lens units varies during zooming, and an aperture diaphragm on the image side of the first lens unit, a combined focal length of the rear unit at a wide-angle end being positive. One lens unit LG on the object side of the aperture diaphragm is made of a solid material, and includes an optical element GnNL having a negative refractive power and another optical element having a positive refractive power, and the predetermined conditions are satisfied.

A zoom lens achieves a high zoom ratio and high optical performance in an entire zoom range. The zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a rear unit which includes at least one lens unit. At least the second lens unit is moved during zooming such that a distance between the first and second lens units is larger at a telephoto end than at a wide-angle end. The first lens unit includes at least a first lens element made of a material which satisfies Nd1a>2.3−0.01·νd1a and 1.65<Nd1a<2.70. The first and second lens units satisfy 2.5<|f1/f2|<12.0.

A zoom lens system, in order from an object side to an image side, comprising a first lens unit having positive optical power and at least one subsequent lens unit, wherein an interval between the first lens unit and a lens unit which is one of the at least one subsequent lens unit varies in zooming, and at least one lens element among all the lens elements constituting the lens system satisfies the condition: 0.0002399×vd²−0.0123×vd+0.8157−θgF<0 (vd<23) or θgF>0.66 (23≦vd<80), or satisfies the condition: −0.00325×vd+0.69−θgF>0 (ω_W>77, vd is an Abbe number to the d-line of the lens element constituting the lens system, θgF is a partial dispersion ratio of the lens element constituting the lens system, ω_W is a view angle at a wide-angle limit); an imaging device; and a camera are provided.

A compact two-group zoom lens that corrects aberrations in the visible and the near infrared regions and that provides a comparatively high zoom ratio includes, in order from the object side, a first lens group of negative refractive power and a second lens group of positive refractive power. The first lens group includes, in order from the object side, first and second negative meniscus lens elements having convex surfaces on the object side, a biconcave lens element, and a positive lens element. The second lens group includes, in order from the object side, a positive lens component which may be a lens element, a negative/positive doublet component, and a negative lens component which may be a lens element. Aspheric lens surfaces are disclosed. Certain conditions are satisfied to control aberrations in both the visible and the near infrared and to ensure a sufficient back focus distance.

An electronic imaging apparatus comprises a zoom lens including at least two lens groups and adapted to implement zooming by changing the spacing between the respective lens groups, and an electronic imaging device. The zoom lens includes at least one positive lens on an imaging device side with respect to an aperture stop, and satisfies the following conditions (1), (2) and (3).

|α_t−α_w|>8   (1)

1.0×10⁻³<P<4.0×10⁻³   (2)

4<f_t/f_w<50   (3)

A four-unit zoom lens system includes in order from an object side, a first lens unit having a positive refracting power, a second lens unit having a negative refracting power, a third lens unit having a positive refracting power, and a fourth lens unit having a positive refracting power, in which at a time of zooming from a wide angle end to a telephoto end, at least the first lens unit, the second lens unit, and the third lens unit move, and a space between the lens units changes, and a total number of lenses in the second lens unit is not more than three, and the zoom lens system satisfies the following conditional expressions.1.2<(beta2t/beta2w)/(beta3t/beta3w)<6.0 and (1A)3.0 G02B 15/16 G02B 15/173 G02B 9/34 G02B 13/18 H04N 5/225 30 80 10 2007/11/15 101183172 2008/5/21 000000000 Olympus Image Corp. Japan Miyajima Toru lihui 11127 San You Patent Agency No.201 Entrance 1, Building 13, the East of Jinmenli, Haidian District, Beijing 100088 Japan 2006/11/15 2006-309666 Japan 2007/6/21 2007-163571

A zoom lens comprises, in the following order from the object side to the image side, a positive first lens unit, a negative second lens unit, which moves during zooming, a positive third lens unit, and a positive fourth lens unit, which moves during zooming. The first lens unit includes a negative lens subunit and a positive lens subunit. The negative lens subunit includes at least two negative lenses each having a concave surface facing the image side and at least one positive lens arranged from the object side. The positive lens subunit includes at least one biconvex positive lens, a negative lens and at least two positive lenses arranged from the object side, or at least one biconvex positive lens, a cemented lens composed of a negative lens and a positive lens and at least one positive lens arranged from the object side.

a zoom lens includes, in order from object side: a positive first unit immovable for zooming; a negative second unit moving during zooming; a third unit moving during zooming; a stop; and a positive fourth unit immovable for zooming. The first unit includes, in order from object side, a fixed negative front first unit, a positive middle first unit moving for focusing, and a fixed positive rear first lens unit. Each of the front first and the second units includes at least one positive lens and two negative lenses. Average of Abbe constants and average of partial dispersion ratios of positive lenses in the front first unit, average of Abbe constants and average of partial dispersion ratios of negative lenses in the front first unit, combined focal length of the positive lenses in the front first unit and focal length of the front first unit are appropriately set.

A zoom lens includes, in order from an object side to an image side, a first lens unit having a positive refractive power and configured to move along an optical axis during zooming, a second lens unit having a negative refractive power and configured to move with a locus convex towards the image side during zooming, a third lens unit having a positive refractive power, and a fourth lens unit having a negative refractive power. The first lens unit is located closer to the object side at a telephoto end than at a wide-angle end and the second lens unit is located closer to the image side at the telephoto end than at the wide-angle end. A focal length of the second lens unit (f2), a focal length of the zoom lens at the wide-angle end (fw), and a focal length of the zoom lens at the telephoto end (ft) are appropriately set.

The invention relates to a slimmed-down, small-format, high-zoom-ratio bent type zoom optical system that can be tucked away in a lens mount and an imaging system incorporating the same. The bent type zoom optical system or taking system comprises, in order from its object side, a first lens group G1 of positive refracting power, a second lens group G2 of negative refracting power and a reflecting mirror R located on an image side with respect to the second lens group G2 for bending an optical axis at substantially right angles upon zooming. Between the reflecting mirror R and an imaging plane I there are a plurality of lens groups G2 and G4 interposed. For zooming, while the spacing between the first G1 and the second lens group G2 varies, at least one lens group of the plurality of lens groups G2 and G4 lying on the imaging plane side of the reflecting mirror R moves. The reflecting mirror R remains fixed with respect to the imaging plane I during taking operation, and upon tucked away in a lens amount, the angle of the reflecting mirror R varies such that the normal to the reflecting surface is substantially parallel with the optical axis through the first G1 and the second lens group G2, and the first G1 and the second lens group G2 draw near to the reflecting mirror R with a narrowing spacing between them.

The invention relates to a compact zoom lens system that has a decreased F-number and can easily achieve a high zoom ratio, and an imaging system that incorporates it. The zoom lens system comprises a first group G1 of positive power, a second group G2 of negative power, a third group G3 of positive power and a fourth group G4 of positive power. Upon zooming, at least the first group G1, the second group G2 and the third group G3 move on an optical axis in such a way that, at a telephoto end with respect to a wide-angle end, the space between the first group G1 and the second group G2 becomes wide, the space between the second group G2 and the third group G3 becomes narrow and the space between the third group G3 and the fourth group G4 becomes wide. The second group G2 is composed of a negative lens L21, a negative lens L22 and a positive lens L23. The zoom lens system satisfies a condition that defines the ratio of the total length (length from the first surface of the lens system to an image plane) to the focal length of the zoom lens system at the wide-angle end.

A zoom lens includes a first lens unit, a second lens unit, a third lens unit and a fourth lens unit that includes a 41 lens group and a 42 lens group. The 41 lens group includes a 411 lens group and a 412 lens group. A lens surface on a most image side of the 411 lens unit has a shape convex to the image side and a lens surface on the most object side of the 412 lens unit has a shape concave to the object side. A curvature radius r411 of the lens surface on the most image side of the 411 lens unit, a curvature radius r412 of the lens surface on the most object side of the 412 lens unit, and lateral magnification β3w of the third lens unit at a wide-angle end are respectively appropriately set.