Focusing apparatus and terminal comprising variable focus lens assembly

An indicia reading terminal comprising:

• a laser source emitting laser light;
• a variable lens assembly for focusing the laser light onto a target, the variable lens assembly having a lens element comprising a deformable membrane and an opposing light transmissive member delimiting optical fluid disposed in a cavity, the lens element having an imaging axis extending thought the deformable membrane, wherein the variable lens assembly further includes an actuator assembly for moving the deformable membrane to thereby change an optical characteristic of the lens element, and wherein the actuator assembly includes a piezoelectric actuator;
• a scanning apparatus for scanning the laser light across the target, wherein the terminal is operative so that a plane of optimum focus of the laser light scanned across the target varies based on a present lens setting of the lens assembly;
• wherein the terminal is operative to move a lens setting of the lens assembly between a first lens setting and a second lens setting, wherein the lens assembly has a first plane of optimum focus at the first lens setting and a second plane of optimum focus at the second lens setting, said terminal further being operative to generate a first signal corresponding to a first scan with the lens assembly at the first lens setting and a second signal corresponding to a second scan with the lens assembly at the second lens setting, and wherein the terminal is further operative to attempt to decode a decodable indicia utilizing the first signal and the second signal, wherein the piezoelectric actuator is provided by a hollowed disc piezoelectric actuator having a hollowed portion disposed about the imaging axis and having a first piezoceramic layer and a second piezoceramic layer that extend substantially in parallel with the deformable membrane.

A focusing apparatus comprising:

• a fluid lens element comprising a deformable membrane partially defining a cavity, the cavity holding optical fluid;
• an actuator assembly operative for imparting force to the fluid lens element to change an optical characteristic of the deformable membrane;
• a pocket into which the fluid lens element is disposed, the pocket being delimited on a first side by a structural member of the actuator assembly;
• wherein there is further disposed in the pocket a resilient member;
• wherein the focusing apparatus is further configured so that a width of the pocket is adapted to be adjusted for achieving a positional relationship of predetermined criteria between the fluid lens element and members of the focusing apparatus that define the pocket, wherein the resilient member in an unstressed state has a greater thickness than the fluid lens element in an unstressed state.