Patent ID: 9417505
Filing Date: 2016-08-16
CPC Classification: G02B,G03B

Claim Text:
1. A lens barrel comprising: an extendable barrel unit; a drive unit configured to drive the barrel unit so as to extend the barrel unit; and a transmission unit configured to transmit a drive force of the drive unit to the barrel unit, wherein the transmission unit includes: a first gear and a second gear coaxially disposed, and a biasing member configured to bias at least one of the first gear and the second gear such that the drive force is transmitted between the first gear and the second gear, and wherein the transmission unit is configured to block transmission of the drive force between the first gear and the second gear depending on a rotational force applied to at least one of the first gear and the second gear, wherein the rotational force causes generation of a reaction force that is larger than a biasing force of the biasing member to block the transmission of the drive force between the first gear and the second gear, wherein the first gear and the second gear are configured to move away from each other in a rotational axis direction by elastic deformation of the biasing member caused by the reaction force, and wherein the first gear includes a drive shaft having an end portion which is provided at a side opposite to the second gear, and wherein the biasing member is configured to bias the end portion of the drive shaft to bias the first gear.