Lens barrel including a correction lens to move for zoom tracking, and imaging apparatus
View Patent ↗A lens barrel includes a correction lens to move for zoom tracking, a zoom lens driver to mechanically move a zoom lens according to an amount of turn of a zoom ring, a storage unit to store relational information associating a zoom lens position with a focus position of the correction lens, and a controller to control the correction lens driver. The controller determines a focus position of the correction lens corresponding to a position distant by a predetermined amount from a detected zoom lens position, by referring to the relational information, and controls the correction lens driver to drive the correction lens to a target position set to the determined focus position. A formula varying with the change rate of the zoom lens position is used to calculate the predetermined amount, and is set according to positions of the zoom lens and the focus lens.
1. A lens barrel comprising:
a correction lens operable to move along an optical axis to perform zoom tracking;
a correction lens driver operable to drive the correction lens;
a zoom lens;
a zoom ring operable to be turned by a user;
a zoom lens driver operable to mechanically move the zoom lens according to an amount of turn of the zoom ring;
a position detector operable to detect a position of the zoom lens;
a rate detector operable to detect a change rate of the position of the zoom lens;
a storage unit operable to store relational information which associates the position of the zoom lens with a focus position of the correction lens; and
a controller operable to control the correction lens driver, wherein
the controller determines a focus position of the correction lens corresponding to a position more distant by a predetermined amount from the position of the zoom lens detected by the position detector, by referring to the relational information, and controls the correction lens driver to drive the correction lens with a target position set to the determined focus position,
the controller changes the predetermined amount according to the change rate of the position of the zoom lens detected by the rate detector,
further the controller uses a calculation formula which varies with the change rate of the zoom lens position to calculate the predetermined amount, and the calculation formula is set according to the position of the zoom lens and the position of a focus lens.
2. The lens barrel according to claim 1 , wherein the correction lens is the focus lens.
3. The lens barrel according to claim 1 , wherein the correction lens is a lens different from the focus lens.
4. An imaging apparatus comprising an interchangeable lens and a camera body to which the interchangeable lens is mountable, wherein
the interchangeable lens includes:
a correction lens operable to move along an optical axis to perform zoom tracking;
a correction lens driver operable to drive the correction lens;
a zoom lens;
a zoom ring operable to be turned by a user;
a zoom lens driver operable to mechanically move the zoom lens according to an amount of turn of the zoom ring;
a position detector operable to detect a position of the zoom lens;
a rate detector operable to detect a change rate of the position of the zoom lens;
a storage unit operable to store relational information which associates the position of the zoom lens with a focus position of the correction lens; and
a controller operable to control the correction lens driver,
the controller determines a focus position of the correction lens corresponding to a position more distant by a predetermined amount from the position of the zoom lens detected by the position detector, by referring to the relational information, and controls the correction lens driver to drive the correction lens with a target position set to the determined focus position, and the controller changes the predetermined amount according to the change rate of the position of the zoom lens detected by the rate detector,
the camera body includes:
an imaging unit operable to generate image data of a subject image captured through the interchangeable lens; and
a recording unit operable to perform a predetermined process on the image data and store the image subjected to the predetermined process in a recording medium,
further the controller uses a calculation formula which varies with the change rate of the zoom lens position to calculate the predetermined amount, and the calculation formula is set according to the position of the zoom lens and the position of a focus lens.
5. The imaging apparatus according to claim 4 , wherein the correction lens is the focus lens.
6. The lens barrel according to claim 4 , wherein the correction lens is a lens different from the focus lens.
7. An imaging apparatus comprising:
a correction lens operable to move along an optical axis for zoom tracking;
a correction lens driver operable to drive the correction lens;
a controller operable to control the correction lens driver;
a zoom lens;
a zoom ring operable to be turned by a user;
a zoom lens driver operable to mechanically move the zoom lens according to an amount of turn of the zoom ring;
a position detector operable to detect a position of the zoom lens;
a rate detector operable to detect a change rate of the position of the zoom lens;
a storage unit operable to store relational information which associates the position of the zoom lens with a focus position of the correction lens;
an imaging unit operable to generate image data of a subject image captured through the correction lens; and
a recording unit operable to perform a predetermined process on the image data and store the image subjected to the predetermined process in a recording medium,
wherein the controller determines a focus position of the correction lens corresponding to a position more distant by a predetermined amount from the position of the zoom lens detected by the position detector, by referring to the relational information, and controls the correction lens driver to drive the correction lens with a target position set to the determined focus position,
the controller changes the predetermined amount according to the change rate of the position of the zoom lens detected by the rate detector,
the controller uses a calculation formula which varies with the change rate of the zoom lens position to calculate the predetermined amount, and the calculation formula is set according to the position of the zoom lens and the position of a focus lens.
8. The imaging apparatus according to claim 7 , wherein the correction lens is the focus lens.
9. The imaging apparatus according to claim 7 , wherein the correction lens is a lens different from a focus lens.