Lens module comprising at least one exchangeable optical element

An optical system, comprising:

• a housing configured with a mount and an opening to a receiving region, the receiving region being located within the housing and including the mount;
• at least one optical element configured to be inserted into and removed from the receiving region through the opening;
• and
• a gas lock configured to receive the at least one optical element;
• wherein the opening interconnects the gas lock and the receiving region of the housing, and is configured to accommodate passage of the optical element between the gas lock and the receiving region.

An optical system, comprising:

• a housing;
• at least one optical element;
• a gas stream source;
• and
• at least one gas seal,
• wherein the housing and the optical element are configured to arrange the optical element selectively in the housing or entirely outside the housing,
• wherein the housing has an inner space including a region of the optical element and a remaining inner space of the housing separated from the region of the optical element by the at least one gas seal, and
• wherein the housing, the gas stream source, and the gas seal are configured to produce a pressure-differential-induced gas stream between the region and the remaining inner space at least when the optical element is arranged in the housing.

A method, comprising:

• inserting or removing an optical element into or from a receiving region in a housing;
• and
• during the inserting or removing, flushing the receiving region in the housing with a gas,
• wherein the inserting or removing is via a push-in opening for the optical element.