Abstract: A zoom lens includes a focus lens unit that moves in focus adjustment, a magnification lens unit including lens units that move in magnification, and a relay lens unit that does not move for magnification, in this order from the object side toward the image side, and a correction lens unit that is disposed in the focus lens unit or magnification lens unit and moves in the optical axis direction to correct displacement of the in-focus position. The amounts of change in in-focus position at the wide angle and telephoto ends with the correction lens unit moved by 1 mm in the optical axis direction, the maximum absolute value of the amount of movement of the correction lens unit for correcting displacement of the in-focus position, and the maximum absolute value of the amount of movement of the lens units in the magnification lens unit are set as appropriate.

Abstract: A strain sensor is provided which includes a strain sensor, a first housing, a second housing joined to the first housing, and a pressure measuring mechanism firmly retained between the first housing and the second housing. The pressure measuring mechanism is gripped between a first face of the first housing and a second face of the second housing to measure compressive stress exerted by a cylinder head of an internal combustion engine on the first housing and the second housing. This structure improves the reliability of mechanical strength of the housings and the pressure measuring mechanism and provides flexibility in selecting the type of the pressure measuring mechanism.

Abstract: Provided is a zoom lens including in order from an object side: a positive first unit configured not to move for zooming; a negative second unit configured to move for zooming; a positive third unit configured to move for zooming; a negative fourth unit configured to move for zooming; and a positive rear unit including at least one lens unit, wherein the fourth unit is configured to move for focusing, and wherein a focal length of the fourth unit, a focal length of the rear unit at a telephoto end, a focal length of the zoom lens at a wide angle end, amounts of movement of the second and third units from the wide angle end to the telephoto end, a half angle of view at the wide angle end, an amount of displacement of an in-focus position.

Abstract: A zoom lens includes, in order from object-side, a fixed positive first group including three-or-more lenses, a negative second group including a unit moving toward image-side during zooming toward telephoto-end, a positive third group including a unit moving toward object-side during zooming from wide-end to telephoto-end, a negative fourth group moving during zooming and focusing, and a rear group. Focal lengths of the first group and the zoom lens at wide-end, a movement amount of a unit moving by largest amount during zooming toward telephoto-end in the second group, a largest value of position change between wide-end and telephoto-end of units moving toward an object side during zooming from wide-end to telephoto-end, refractive index for d-line of a positive lens closest to image-side in the first group, and average refractive index for d-line of positive lenses of the first group other than the positive lens are appropriately set.

Abstract: In a combustion pressure sensor, a sensor holder is installed in a housing. The sensor holder has an end contact surface. A load transfer member is installed in the housing. The load transfer member has a contact surface facing the end contact surface of the sensor holder. The contact surface of the load transfer member is in contact with the end contact surface of the sensor holder. One of the contact surface of the load transfer member and the end contact surface of the sensor holder has a concavely curved shape, and the other thereof has a convexly curved shape.

Abstract: A zoom lens, including, in order from an object side: a negative first unit being not moved for zooming; a second unit including at least one sub-unit that is moved during zooming, and having a positive refractive power as a whole; a negative third unit including an aperture stop, being not moved for zooming; a fourth unit including at least one sub-unit and being moved during zooming; and a fifth unit being not moved for zooming, at least three sub-units among the sub-units included in the second and fourth units being moved during zooming, in which focal lengths of the first and third units, and a movement amount of a sub-unit that is moved most in the second unit and a movement amount of a sub-unit that is moved most in the fourth unit during zooming from a wide angle end to a telephoto end satisfy predetermined conditions.

Abstract: Provided is a zoom lens, including, in order from object side: a positive first unit; a negative second unit; a positive third unit; a negative fourth unit; and a positive fifth unit, in which: intervals between adjacent units are changed during zooming; the first unit is not moved in an optical axis direction for zooming, and the second, third, and fourth units are moved in the optical axis direction during zooming; the fourth unit is moved in the optical axis direction during focusing; the third unit includes, in order from the object side, a positive first subunit, and a positive second subunit, and the second subunit is moved during image stabilization in a direction having a component in a direction orthogonal to the optical axis; and focal lengths of the first, third, fourth unit, and the zoom lens at a wide angle end are appropriately set.

Abstract: A zoom lens includes, in order from object-side, a fixed positive first group including three-or-more lenses, a negative second group including a unit moving toward image-side during zooming toward telephoto-end, a positive third group including a unit moving toward object-side during zooming from wide-end to telephoto-end, a negative fourth group moving during zooming and focusing, and a rear group. Focal lengths of the first group and the zoom lens at wide-end, a movement amount of a unit moving by largest amount during zooming toward telephoto-end in the second group, a largest value of position change between wide-end and telephoto-end of units moving toward an object side during zooming from wide-end to telephoto-end, refractive index for d-line of a positive lens closest to image-side in the first group, and average refractive index for d-line of positive lenses of the first group other than the positive lens are appropriately set.

Abstract: A strain sensor is provided which includes a strain sensor, a first housing, a second housing joined to the first housing, and a pressure measuring mechanism firmly retained between the first housing and the second housing. The pressure measuring mechanism is gripped between a first face of the first housing and a second face of the second housing to measure compressive stress exerted by a cylinder head of an internal combustion engine on the first housing and the second housing. This structure improves the reliability of mechanical strength of the housings and the pressure measuring mechanism and provides flexibility in selecting the type of the pressure measuring mechanism.

Abstract: A zoom lens includes a focus lens unit that moves in focus adjustment, a magnification lens unit including lens units that move in magnification, and a relay lens unit that does not move for magnification, in this order from the object side toward the image side, and a correction lens unit that is disposed in the focus lens unit or magnification lens unit and moves in the optical axis direction to correct displacement of the in-focus position. The amounts of change in in-focus position at the wide angle and telephoto ends with the correction lens unit moved by 1 mm in the optical axis direction, the maximum absolute value of the amount of movement of the correction lens unit for correcting displacement of the in-focus position, and the maximum absolute value of the amount of movement of the lens units in the magnification lens unit are set as appropriate.

Abstract: Provided is a zoom lens including, in order from an object side: a first lens unit not moving for zooming; a second lens unit moving during the zooming; at least one lens unit moving during the zooming; and a rear lens group. The first lens unit includes a first lens sub unit not moving for focusing, and a second lens sub unit moving during the focusing. The first lens sub unit includes a negative lens and a positive lens. A focal length of the first lens unit, a distance on an optical axis from a lens surface closest to an image side of the first lens sub unit to a rear principal point position of the first lens sub unit, and a focal length of the zoom lens at a telephoto end are appropriately set.

Abstract: A zoom lens, including, in order from object side: a positive first unit which is fixed during zooming; a negative second unit which moves for zooming; a positive third unit which moves for zooming; a positive fourth unit which moves for zooming; and a positive fifth unit which is fixed during zooming, in which 1.50<LN(Z2)/LN(Z34)<2.30 and 0.70<f34w/f34t<0.96 are satisfied, where LN(Z2) is natural logarithm of Z2 obtained by dividing a lateral magnification ?2t of the second unit at telephoto end by a lateral magnification ?2w at wide angle end, LN(Z34) is natural logarithm of Z34 obtained by dividing a combined lateral magnification ?34t of the third unit and the fourth unit at telephoto end by a combined lateral magnification ?34w at wide angle end, and f34w and f34t are combined focal lengths of the third unit and the fourth unit at wide angle end and telephoto end, respectively.

Abstract: A zoom lens including, in order from object side, a positive first lens unit not moving for zooming, a negative second lens unit moving during zooming, at least one other lens unit moving during zooming as at least a third lens unit, and a rearmost lens unit closest to an image side not moving for zooming, and also including an aperture stop at the image side of the second lens unit, average values of Abbe numbers and relative partial dispersions of each of positive lenses and negative lenses forming the second lens unit, anomalous dispersion of a lens having a smallest Abbe number of negative lenses forming the rearmost lens unit, an axial distance between surface vertex positions of lenses closest to the object and image sides of the zoom lens, and a distance between the aperture stop and the negative lens at a wide angle end are appropriately set.

Abstract: In a combustion pressure sensor, a sensor holder is installed in a housing. The sensor holder has an end contact surface. A load transfer member is installed in the housing. The load transfer member has a contact surface facing the end contact surface of the sensor holder. The contact surface of the load transfer member is in contact with the end contact surface of the sensor holder. One of the contact surface of the load transfer member and the end contact surface of the sensor holder has a concavely curved shape, and the other thereof has a convexly curved shape.

Abstract: A zoom lens includes, in order from an object side to an image side: a first lens unit having a positive refractive power that does not move for zooming; a second lens unit having a negative refractive power that moves during zooming; a third lens unit having a positive refractive power that moves during zooming; and at least one lens unit having a positive refractive power, and focal lengths of the zoom lens at a wide angle end and a telephoto end, a maximum value of a half angle of field at the wide angle end, and products of lateral magnifications of lens units arranged on the image side of the third lens unit in a state in which focus is at infinity at the telephoto end and the wide angle end are appropriately set.

Abstract: A zoom lens, including, in order from an object side: a negative first unit being not moved for zooming; a second unit including at least one sub-unit that is moved during zooming, and having a positive refractive power as a whole; a negative third unit including an aperture stop, being not moved for zooming; a fourth unit including at least one sub-unit and being moved during zooming; and a fifth unit being not moved for zooming, at least three sub-units among the sub-units included in the second and fourth units being moved during zooming, in which focal lengths of the first and third units, and a movement amount of a sub-unit that is moved most in the second unit and a movement amount of a sub-unit that is moved most in the fourth unit during zooming from a wide angle end to a telephoto end satisfy predetermined conditions.

Abstract: A zoom lens including, in order from object side, a positive first lens unit not moving for zooming, a negative second lens unit moving during zooming, at least one other lens unit moving during zooming as at least a third lens unit, and a rearmost lens unit closest to an image side not moving for zooming, and also including an aperture stop at the image side of the second lens unit, average values of Abbe numbers and relative partial dispersions of each of positive lenses and negative lenses forming the second lens unit, anomalous dispersion of a lens having a smallest Abbe number of negative lenses forming the rearmost lens unit, an axial distance between surface vertex positions of lenses closest to the object and image sides of the zoom lens, and a distance between the aperture stop and the negative lens at a wide angle end are appropriately set.

Abstract: Provided is a zoom lens including, in order from an object side: a first lens unit not moving for zooming; a second lens unit moving during the zooming; at least one lens unit moving during the zooming; and a rear lens group. The first lens unit includes a first lens sub unit not moving for focusing, and a second lens sub unit moving during the focusing. The first lens sub unit includes a negative lens and a positive lens. A focal length of the first lens unit, a distance on an optical axis from a lens surface closest to an image side of the first lens sub unit to a rear principal point position of the first lens sub unit, and a focal length of the zoom lens at a 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 that does not move for zooming; a second lens unit having a negative refractive power that moves during zooming; a third lens unit having a positive refractive power that moves during zooming; and at least one lens unit having a positive refractive power, and focal lengths of the zoom lens at a wide angle end and a telephoto end, a maximum value of a half angle of field at the wide angle end, and products of lateral magnifications of lens units arranged on the image side of the third lens unit in a state in which focus is at infinity at the telephoto end and the wide angle end are appropriately set.

Abstract: A zoom lens includes, in order from the object side, a positive first lens unit which does not move for zooming or focusing, a negative second lens unit which moves during zooming, a positive third lens unit which moves during zooming, a negative fourth lens unit which moves during zooming and focusing, and a positive fifth lens unit which does not move for zooming or focusing. An aperture stop which does not move for zooming or focusing is arranged adjacent to the fourth lens unit. The focal lengths of the second, third, and fourth lens units, a zoom ratio of the zoom lens at infinity focus, the lateral magnification of the third lens unit at the wide angle end and the telephoto end at infinity focus, the lateral magnifications of the fourth and fifth lens units at the telephoto end at infinity focus are appropriately set.