Focusing apparatus for a surveying instrument
First Claim
1. A focusing apparatus for a surveying instrument including an objective lens, a focusing lens, and a reticle, in which said focusing lens is movable to form an image of an object on said reticle, comprising:
- a motor which drives said focusing lens in an optical axis direction;
means for detecting a focus state of the image of an object and for controlling said motor in accordance with said detected focus state;
a rotating shaft member rotated by a rotation of said motor to thereby move said focusing lens in the optical axis direction;
a focusing knob which is coaxial with said rotating shaft member and movable in an axial direction thereof; and
a plurality of clutches which disengageably engage one of said focusing knob and said motor with said rotating shaft member, according to an axial movement of said focusing knob.
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Accused Products
Abstract
A focusing apparatus for a surveying instrument including an objective lens, a focusing lens and a reticle. The focusing lens is movable in an optical axis direction, by a rotating shaft member which is rotated by a motor, to form an image, of an object to be surveyed, on the reticle. Means for detecting a focus state of the object image and for controlling the motor in accordance with the detected focus state are provided. A focusing knob, coaxial with the rotating shaft member, and movable in an axial direction thereof is also provided. A plurality of clutches disengageably engages the focusing knob or the motor with the rotating shaft member, according to an axial movement of the focusing knob.
17 Citations
22 Claims
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1. A focusing apparatus for a surveying instrument including an objective lens, a focusing lens, and a reticle, in which said focusing lens is movable to form an image of an object on said reticle, comprising:
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a motor which drives said focusing lens in an optical axis direction; means for detecting a focus state of the image of an object and for controlling said motor in accordance with said detected focus state; a rotating shaft member rotated by a rotation of said motor to thereby move said focusing lens in the optical axis direction; a focusing knob which is coaxial with said rotating shaft member and movable in an axial direction thereof; and a plurality of clutches which disengageably engage one of said focusing knob and said motor with said rotating shaft member, according to an axial movement of said focusing knob. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A focusing apparatus for a surveying instrument including an objective lens, a focusing lens, a reticle and an eyepiece, for adjusting a position of said focusing lens along an optical axis thereof to bring an image of an object into focus on said reticle, said focusing apparatus comprising:
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means for detecting a focus state of said object image relative to said reticle; a motor for driving said focusing lens along said optical axis; a rotating shaft member rotated by said motor to move said focusing lens along said optical axis; means for controlling said motor in accordance with said focus state detected by said detecting means; a focusing knob which is coaxial with said rotating shaft member and movable in an axial direction thereof; and a plurality of clutches which disengageably engage one of said focusing knob and said motor with said rotating shaft member, according to an axial movement of said focusing knob.
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22. A level having a focusing apparatus for adjusting a position of a focusing lens of a telescope, provided on said level, along an optical axis thereof to bring an image of an object observed through said telescope into focus, said focusing apparatus comprising:
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means for detecting a focus condition of said object image; a motor for driving said focusing lens along said optical axis; a rotating shaft member rotated by said motor to move said focusing lens along said optical axis; means for controlling said motor in accordance with said focus state detected by said detecting means; a focusing knob which is coaxial with said rotating shaft member and movable in an axial direction thereof; a first clutch which disengages said focusing knob from said rotating shaft member and engages said motor with said rotating shaft member when said focusing knob is moved in one axial direction, so that said focusing lens can be controlled by said control means; and a second clutch which disengages said motor from said rotating shaft member and engages said focusing knob with said rotating shaft member when said focusing knob is moved in another axial direction, so that said focusing lens can be manually adjusted by said focusing knob.
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Specification