US 6,788,890 B2Granted

Switching mechanism of a lens barrel for switching between automatic and manual focusing modes

AssigneePENTAX Corporation

InventorHiroaki Suzuki

Life of this patent

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Abstract

A switching mechanism of a lens barrel includes a stationary barrel having a stop groove; a lens holding ring, a distance adjustment ring and an AF/MF switching ring, each positioned concentrically with the stationary barrel. The AF/MF switching ring is prevented from rotating relative to the stationary barrel by engagement of the engaging member with the stop groove while a driving force is transferred from a power source to the distance adjustment ring to move the lens holding ring along the optical axis when the AF/MF switching ring is in the AF position. Rotation of the AF/MF switching ring is transferred to the distance adjustment ring to move the lens holding ring along the optical axis while the driving force is prevented from being transferred from the power source to the distance adjustment ring when the AF/MF switching ring is in the MF position.

Claims11

Dependent claims

A switching mechanism of a lens barrel for switching between an automatic focusing mode and a manual focusing mode, said switching mechanism comprising:

a stationary barrel having at least one stop groove;
a lens holding ring, positioned concentrically with said stationary barrel, said lens holding ring holding at least one lens group;
a distance adjustment ring which is positioned concentrically with said stationary barrel, immovable along an optical axis relative to said stationary barrel, and rotatable about said optical axis relative to said stationary barrel, wherein a rotation of said distance adjustment ring causes said lens holding ring to move along said optical axis, and wherein said distance adjustment ring includes at least one engaging groove;
an AF/MF switching ring which is positioned concentrically with said stationary barrel, movable along said optical axis relative to said stationary barrel, and rotatable about said optical axis relative to said stationary barrel, wherein movement of said AF/MF switching ring relative to said stationary barrel between an AF position and an MF position switches between said automatic focusing mode and said manual focusing mode, respectively;
and
an engaging member provided on said AF/MF switching ring, said engaging member being selectively engaged with said stop groove and said engaging groove,
wherein said AF/MF switching ring is prevented from rotating relative to said stationary barrel by engagement of said engaging member with said stop groove while a driving force is transferred from a power source to said distance adjustment ring to move said lens holding ring along said optical axis when said AF/MF switching ring is in said AF position, and
wherein a rotation of said AF/MF switching ring is transferred to said distance adjustment ring to move said lens holding ring along said optical axis via engagement of said engaging member with said engaging groove while said driving force is prevented from being transferred from said power source to said distance adjustment ring when said AF/MF switching ring is in said MF position.

5 more elements

A switching mechanism of a lens barrel for switching between an automatic focusing mode and a manual focusing mode, said switching mechanism comprising:

a stationary barrel having at least one stop groove;
a lens holding ring holding at least one lens group which functions as a focusing lens, said lens holding ring being movable in an optical axis direction;
a distance adjustment ring being relatively rotatable with respect to said stationary barrel so that a rotation of said distance adjustment ring causes said lens holding ring to move along the optical axis, said distance adjustment ring being provided with at least one engaging groove;
an AF/MF switching ring being movable between an AF position and an MF position along said optical axis and rotatable relative to said stationary barrel;
an AF driving power mechanism which rotates the distance adjustment ring when the AF/MF switching ring is positioned at the AF position in accordance with object distance information;
and
a first engaging portion and a second engaging portion which are fixed at opposite ends of a leaf spring in said optical axis direction to be engageable with said stop groove and said engaging groove, respectively, said leaf spring being elongated in said optical axis direction and a central portion thereof being fixed to said AF/MF switching ring,
wherein said leaf spring is resiliently deformed to move said first engaging portion to a non-engaging position thereof, wherein said first engaging portion is disengaged from said stop groove, when said AF/MF switching ring moves from said MF position to said AF position in the case where said first engaging portion is not aligned with said stop groove in the circumferential direction thereof, and
wherein said leaf spring is resiliently deformed to move said second engaging portion to a non-engaging position thereof wherein said second engaging portion is disengaged from said engaging groove when said AF/MF switching ring moves from said AF position to said MF position in the case where said second engaging portion is not aligned with said engaging groove in said circumferential direction.

6 more elements

A switching mechanism of a lens barrel for switching between an automatic focusing mode and a manual focusing mode, said switching mechanism comprising:

a stationary ring having a first plurality of engaging grooves arranged at equi-angular intervals about an optical axis;
an AF/MF switching ring fitted on said stationary ring to be manually movable along said optical axis relative to said stationary ring between an AF position and an MF position to switch between said automatic focusing mode and said manual focusing mode, respectively;
a rotatable ring fitted in said stationary ring to be rotatable about said optical axis without moving along said optical axis relative to said stationary ring, said rotatable ring having a second plurality of engaging grooves arranged at equi-angular intervals about an optical axis;
and
an engaging member fixed to opposite ends of a leaf spring in the optical axis direction, said leaf spring fixed to said AF/MF switching ring, wherein said engaging member includes a first engaging portion and a second engaging portion which are engageable in any one of said first plurality of engaging grooves and any one of said second plurality of engaging grooves, respectively,
wherein said first engaging portion of said engaging member is engaged in one of said first plurality of engaging grooves when said AF/MF switching ring moves from said MF position to said AF position in the case where said first engaging portion is aligned with said one first engaging groove in the circumferential direction thereof,
wherein said second engaging portion of said engaging member is engaged in one of said second plurality of engaging grooves when said AF/MF switching ring moves from said AF position to said MF position in the case where said second engaging portion is aligned with said one second engaging groove in the circumferential direction thereof, and
wherein said leaf spring is resiliently deformed so that said first engaging portion moves radially outwards when said AF/MF switching ring moves from said MF position to said AF position in the case where said first engaging portion is not aligned with said one first engaging groove in the circumferential direction, and so that said second engaging portion moves radially outwards when said AF/MF switching ring moves from said AF position to said MF position in the case where said second engaging portion is not aligned with said one second engaging groove in said circumferential direction thereof.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/684,411Filed 15 Oct 2003
Priority: JP 2002-30267917 Oct 2002
Published: US 2004/0081442 A129 Apr 2004
Granted: 7 Sep 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G02B 7/04
For lenses: with mechanism for focusing or varying magnification
G02B 7/08
With mechanism for focusing or varying magnification: adapted to co-operate with a remote control mechanism
G03B 3/00
Focusing arrangements of general interest for cameras, projectors or printers
G02B
Optical elements, systems or apparatus