LENS APPARATUS AND IMAGE-PICKUP APPARATUS

Abstract

Provided is a lens apparatus mounted to a camera including an image-pickup element, including: a focus lens means movable in an optical axis direction for focusing; a zoom lens unit; a zoom detector for detecting a zoom value of the zoom lens unit; an aperture-stop device; a stop-value detector; a splitting optical unit; a focus-condition detection unit; an actuator; a controller for controlling the actuator based on an output from the focus-condition detection unit; and a manual operation member, wherein the controller obtains an F-number of the lens apparatus based on outputs from the zoom detector and stop-value detector and when the F-number exceeds a predetermined value, the controller causes the actuator to stop the focus lens unit and switches to a condition in which the focus lens unit is driven by the manual operation member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural diagram illustrating a first Embodiment of the present invention.

FIG. 2 is an optical structural diagram illustrating a focus-condition detector.

FIG. 3 is an optical path diagram illustrating a state where an aperture stop is stopped down so that a stop value exceeds a threshold value of an F-number.

FIG. 4 is an optical path diagram illustrating a state where the aperture stop is further stopped down so that the stop value exceeds the threshold value of the F-number.

FIG. 5 is a flowchart illustrating an operation in a first Embodiment of the present invention.

FIG. 6 is a structural diagram illustrating a second Embodiment of the present invention.

FIG. 7 is a flowchart illustrating an operation in a second Embodiment of the present invention.

FIG. 8 is a structural diagram illustrating a third Embodiment of the present invention.

FIG. 9 is a flowchart illustrating an operation in a third Embodiment of the present invention.

FIG. 10 is a structural diagram illustrating a fourth Embodiment of the present invention.

FIG. 11 is a structural diagram illustrating a fifth Embodiment of the present invention.

Claims

1. A lens apparatus for mounting on a camera including an image-pickup element, comprising: a focus lens unit which is movable in an optical axis direction for focusing;a zoom lens unit which is movable in the optical axis direction for zooming;a zoom detector for detecting a zoom value of the zoom lens unit;an aperture-stop device in which an aperture which can change in size to adjust a light quantity;a stop-value detector for detecting a stop value of the aperture-stop device;a splitting optical unit disposed between the aperture-stop device and the image-pickup element;a focus-condition detection unit for detecting a focus condition based on light from the splitting optical unit;an actuator for driving the focus lens unit in the optical axis direction;a controller for controlling the actuator based on an output from the focus-condition detection unit; anda manual operation member for moving the focus lens unit in the optical axis direction by a manual operation, wherein:the controller is configured to obtain an F-number of the lens apparatus based on an output from the zoom detector and an output from the stop-value detector; andwhen the F-number, adjustable by the stop value of the aperture stop device, exceeds a predetermined value, the controller causes the actuator to stop movement of the focus lens unit and switches to a condition in which the focus lens unit can be driven by the manual operation member.

2. A lens apparatus according to claim 1, wherein the zoom lens unit comprises a magnification lens unit and a lens unit for correcting an image point displaced by magnification, which are arranged in the stated order from an object side.

3. A lens apparatus according to claim 1, further comprising a light-quantity-adjusting member, wherein: the controller has a first light-quantity-adjustment mode and a second light-quantity-adjustment mode; the lens apparatus arranged so thatin the first light-quantity-adjustment mode, the light quantity is adjusted only by the aperture-stop device; andin the second light-quantity-adjustment mode, in the case that the light quantity is to be further reduced such that the F-number would exceed a threshold value: the F-number adjusted by the aperture-stop device is held at a value equal to or smaller than the threshold value, the light quantity is adjusted by the light-quantity-adjusting member, and the focus lens unit may be continuously moved by the actuator.

4. A lens apparatus according to claim 3, wherein: the light-quantity-adjusting member is operative to continuously adjust a light amount; andthe controller is configured to hold the F-number adjusted by the aperture-stop device at the threshold value while the light quantity is being adjusted by the light-quantity-adjusting member.

5. A lens apparatus according to claim 3, wherein the light-quantity-adjusting member is operative to adjust a light control amount stepwise.

6. An image-pickup apparatus, comprising: the lens apparatus according to claim 1; anda camera main body to which the lens apparatus is mounted, the camera main body including an image-pickup element.

7. An image-pickup apparatus according to claim 6, further comprising a light-quantity-adjusting member housed in the camera main body, the controller has a first light-quantity-adjustment mode and a second light-quantity-adjustment mode; the lens apparatus arranged so thatin the first light-quantity-adjustment mode, the light quantity is adjusted only by the aperture-stop device; andin the second light-quantity-adjustment mode, in the case that the light quantity is to be further reduced such that the F-number would exceed a threshold value: the F-number adjusted by the aperture-stop device is held at a value equal to or smaller than the threshold value, the light quantity is adjusted by the light-quantity-adjusting member, and the focus lens unit may be continuously moved by the actuator.

8. An image pickup apparatus according to claim 7 wherein: the light-quantity-adjusting member is operative to continuously adjust a light amount; andthe controller is arranged to hold the F-number adjusted by the aperture-stop device at the threshold value while the light quantity is being adjusted by the light-quantity-adjusting member.

9. A method of controlling a lens apparatus, which lens apparatus comprises a focus lens unit which is moveable in an optical axis direction for focusing, a zoom lens unit which is movable in the optical axis direction for zooming, a zoom detector for detecting a zoom value of the zoom lens unit, an aperture stop device in which an aperture can change in size to adjust light quantity, a splitting optical unit disposed between the aperture-stop device and the image-pickup element, a focus-condition detection unit for detecting a focus condition based on light from the splitting optical unit, an actuator for driving the focus lens unit in the optical axis direction, a controller for controlling the actuator based on an output from the focus-condition detection unit, and a manual operation member for moving the focus lens unit in the optical axis direction by manual operation, the method comprising the steps of: obtaining an F-number of the lens apparatus based on an output from the zoom detector and an output from the stop-value detector; andwhen the F-number, adjustable by the stop value of the aperture-stop device, exceeds a predetermined value, causing the actuator to stop movement of the focus lens unit and to switch to a condition in which the focus lens unit can be driven by the manual operation member.

10. A program that, when run on a controller of a lens apparatus, causes the lens apparatus to perform a method according to claim 9.

11. A storage medium storing a program according to claim 10.