Patent ID: 7945153

Claim:
A focus adjustment mechanism used for a photo device with a casing, for adjusting a focus of a lens assembly of the photo device, the focus adjustment mechanism comprising: a focus adjustment button connected to the casing of the photo device, with the focus adjustment button comprising a contact portion; and a pressure detection module disposed in the photo device in a position corresponding to the focus adjustment button to contact the contact portion, with the pressure detection module electrically coupled with the lens assembly; wherein the pressure detection module comprises: a casing, wherein an outside bottom surface of the casing is fixed to the photo device and an outside top surface of the casing is close to the contact portion of the focus adjustment button and has a hole; an action element comprising a slab with a side removably received in the casing and a protrusion, which is located on a top surface of the slab, passes through the hole of the casing to be against the contact portion of the focus adjustment button, wherein a joint groove is formed on three lateral surfaces of the action element; an elastic electric member comprising a fringe rod connected to the slab, and a rebounding portion which is formed by bending the end of the fringe rod and is against the inside bottom surface of the casing, wherein the fringe rod of the elastic electric member is a U-shaped metal rod that infixes the joint groove; a resistance member disposed within a side of the casing and touching the fringe rod of the elastic electric member; wherein when the protrusion is pressed to make the slab descend produces a position of the resistance member being touched by the fringe rod, so as to make the resistance member perform a corresponding resistance value in association with the movement of the slab; and a conductive member disposed within a side of the casing different from the side where the resistance member is located and touching the fringe rod of the elastic electric member; wherein when the focus adjustment button is pressed, the pressure detection module outputs a signal value according to a displacement value of the focus adjustment button by being pressed so that the focus of the lens assembly is determined according to each signal value.