Abstract: A projection lens includes a plurality of lens units, and a diaphragm, wherein in a case where a lens unit that moves in an optical axis direction of the projection lens during focusing serves as a focus lens unit among the plurality of lens units, at least one lens included in a lens unit that is different from the focus lens unit among the plurality of lens units and is disposed more towards a reduction conjugate side than the diaphragm is configured to move in the optical axis direction when an amount of field curvature is adjusted to focus on a curved projection surface, and wherein when the amount of field curvature is adjusted, both the at least one lens and the focus lens unit move in the optical axis direction.

Abstract: A projection lens includes a plurality of lens units, and a diaphragm, wherein in a case where a lens unit that moves in an optical axis direction of the projection lens during focusing serves as a focus lens unit among the plurality of lens units, at least one lens included in a lens unit that is different from the focus lens unit among the plurality of lens units and is disposed more towards a reduction conjugate side than the diaphragm is configured to move in the optical axis direction when an amount of field curvature is adjusted to focus on a curved projection surface, and wherein when the amount of field curvature is adjusted, both the at least one lens and the focus lens unit move in the optical axis direction.

Abstract: An optical system includes, in order from an enlargement conjugate side to a reduction conjugate side, a front unit including three or more lenses, a diaphragm, and a rear unit including a plurality of lenses. The front unit includes a first positive lens closest to an enlargement conjugate position, and a second positive lens. A predetermined condition is satisfied.

Abstract: An optical apparatus includes a deflection unit configured to deflect illumination light from a light source to scan an object and to deflect reflected light from the object, a light guiding unit configured to guide the illumination light from the light source to the deflection unit and to guide the reflected light from the deflection unit to a light receiving element, and an optical system configured to guide the illumination light from the deflection unit to the object and to guide the reflected light from the object to the deflection unit. The optical system includes a front lens unit that consists of lenses located closer to the object than an intermediate image and a rear lens unit that consists of lenses located closer to the deflection unit than the intermediate image. The rear lens unit consists of three or more and five or less positive lenses.

Abstract: A projection lens includes a plurality of lens units, and a diaphragm, wherein in a case where a lens unit that moves in an optical axis direction of the projection lens during focusing serves as a focus lens unit among the plurality of lens units, at least one lens included in a lens unit that is different from the focus lens unit among the plurality of lens units and is disposed more towards a reduction conjugate side than the diaphragm is configured to move in the optical axis direction when an amount of field curvature is adjusted to focus on a curved projection surface, and wherein when the amount of field curvature is adjusted, both the at least one lens and the focus lens unit move in the optical axis direction.

Abstract: Provided is a small zoom lens having a high zoom ratio and easily designed to achieve favorable optical properties in an entire zooming range. A zoom lens includes, in order from object side to image side, a positive first unit, a negative second unit, an aperture stop, and a rear group including multiple units. Intervals between the adjacent units are changed during zooming. In the rear group, a positive lens unit is arranged on the most image side, and a negative lens unit is on the object side of the positive lens unit. The aperture stop not moving for zooming, but the second unit and the negative lens unit moving during zooming. Focal lengths of the second unit and the positive and negative lens units, and movement amounts of the second and negative lens units, respectively, during zooming from wide angle end to telephoto end are appropriately set.

Abstract: The zoom lens according to the present invention includes, in order from an object side to an image side, a negative first lens unit, an aperture stop, a positive second lens unit, and a positive rear lens group. The rear lens group includes a negative lens unit LN and a positive lens unit LP. During zooming, the first lens unit does not move, the second lens unit moves so as to be closer to object side at a telephoto end (TE) than at a wide-angle end (WE), the lens unit LP moves so as to be closer to image side at TE than at WE, and an interval between every adjacent two of lens units changes. Focal lengths of second lens unit and lens unit LP, and an amount by which each of second lens unit and lens unit LP moves for zooming from WE to TE are appropriately set.

Abstract: A 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, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a rear unit including at least one lens unit. In the zoom lens, the locus of movement, the focal length, the amount of displacement during zooming, and the shapes of lens surfaces are appropriately set for each lens unit.

Abstract: Provided is a zoom lens comprising in order from an object side to an image side, a positive first lens unit including a diffractive optical element, a negative second lens unit, a positive third lens unit including at least one positive lens, and a rear unit including one or more lens units, in which intervals between adjacent lens units are changed during zooming. The third lens unit comprises a positive lens formed by using a material with an Abbe number and a partial dispersion ratio concerning a C-line and a t-line both of which are appropriately set. In the zoom lens, a focal length of the first lens unit and a back focus of the zoom lens when focusing on infinity at a telephoto end are appropriately set.

Abstract: The zoom lens according to the present invention includes, in order from an object side to an image side, a negative first lens unit, an aperture stop, a positive second lens unit, and a positive rear lens group. The rear lens group includes a negative lens unit LN and a positive lens unit LP. During zooming, the first lens unit does not move, the second lens unit moves so as to be closer to object side at a telephoto end (TE) than at a wide-angle end (WE), the lens unit LP moves so as to be closer to image side at TE than at WE, and an interval between every adjacent two of lens units changes. Focal lengths of second lens unit and lens unit LP, and an amount by which each of second lens unit and lens unit LP moves for zooming from WE to TE are appropriately set.

Abstract: Provided is a small zoom lens having a high zoom ratio and easily designed to achieve favorable optical properties in an entire zooming range. A zoom lens includes, in order from object side to image side, a positive first unit, a negative second unit, an aperture stop, and a rear group including multiple units. Intervals between the adjacent units are changed during zooming. In the rear group, a positive lens unit is arranged on the most image side, and a negative lens unit is on the object side of the positive lens unit. The aperture stop not moving for zooming, but the second unit and the negative lens unit moving during zooming. Focal lengths of the second unit and the positive and negative lens units, and movement amounts of the second and negative lens units, respectively, during zooming from wide angle end to telephoto end are appropriately set.

Abstract: A 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, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a rear unit including at least one lens unit. In the zoom lens, the locus of movement, the focal length, the amount of displacement during zooming, and the shapes of lens surfaces are appropriately set for each lens unit.

Abstract: A zoom lens includes, in order from object side to image side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power. During zooming, the first lens unit and the second lens unit move so that the distance between the first lens unit and the second lens unit changes. The first lens unit includes at least one positive lens and at least one negative lens. The total length of the zoom lens at the wide angle end, the back focal length at the wide angle end, the focal length of the zoom lens at the telephoto end, the focal length of the first lens unit, the focal length of the second lens unit, and the refractive index of the material of the at least one positive lens included in the first lens unit are each appropriately set according to mathematical conditions.

Abstract: A zoom lens includes, in order from an object side to an image side, first to fourth lens units having negative, positive, negative, and positive refractive power, respectively. During zooming from a wide-angle end to a telephoto end, at least the first, second, and third lens units move. The focal lengths of the first, second, and third lens units, the amount of movement of the second lens unit during zooming from the wide-angle end to the telephoto end, a lateral magnification at the wide-angle end of the second lens unit, a lateral magnification at the wide-angle end of the third lens unit, a lateral magnification at the telephoto end of the second lens unit, and the lateral magnification at the telephoto end of the third lens unit are appropriately set.

Abstract: A zoom lens includes, in order from object side to image side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power. During zooming, the first lens unit and the second lens unit move so that the distance between the first lens unit and the second lens unit changes. The first lens unit includes at least one positive lens and at least one negative lens. The total length of the zoom lens at the wide angle end, the back focal length at the wide angle end, the focal length of the zoom lens at the telephoto end, the focal length of the first lens unit, the focal length of the second lens unit, and the refractive index of the material of the at least one positive lens included in the first lens unit are each appropriately set according to mathematical conditions.

Abstract: A zoom lens includes, in order from an object side to an image side, first to fourth lens units having negative, positive, negative, and positive refractive power, respectively. During zooming from a wide-angle end to a telephoto end, at least the first, second, and third lens units move. The focal lengths of the first, second, and third lens units, the amount of movement of the second lens unit during zooming from the wide-angle end to the telephoto end, a lateral magnification at the wide-angle end of the second lens unit, a lateral magnification at the wide-angle end of the third lens unit, a lateral magnification at the telephoto end of the second lens unit, and the lateral magnification at the telephoto end of the third lens unit are appropriately set.

Abstract: A zoom lens includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power and configured to move during a zooming operation, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power and configured to move during a zooming operation. The first lens unit has a negative lens closest to an object side, and includes at least five lenses.

Abstract: A zoom lens includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power and configured to move during a zooming operation, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power and configured to move during a zooming operation. The first lens unit has a negative lens closest to an object side, and includes at least five lenses.