Mirrorless cameras may be lighter without the mirror, but swap lenses and there’s nothing in between the sensor and that dust floating in the air. The brains at Canon, however, are working on a potential solution as Canon patents a retractable barrier that would help shield the sensor while swapping lenses.

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Canon’s mirrorless cameras already close the shutter mechanism when switching lenses. By putting that shutter over the sensor, the idea is that the sensor will be less susceptible to dust and dirt. But, Canon’s use of the shutter mechanism itself isn’t perfect. Many photographers have expressed concern over what exposing the shutter to the elements—even temporarily—is doing to the shutter itself. That, in turn raises questions on reliability. With normal use, the shutter on a digital camera is often the hardware that wears out first.

The mechanism is situated just behind the lens mount in the camera body. Unlike using the shutter itself, the design could potentially help protect the shutter mechanism as well as the sensor. The device functions like an internal body cap, but is designed to be used while swapping lenses. The traditional body cap would likely still be used for storing the camera without a lens attached.

But, what’s perhaps the most interesting is that the protective barrier is automatic. The patent suggests that a series of physical components will pull the barrier in place when the lens unlocks and retract once a lens is locked again.

[Read: Canon EOS Mirrorless Set to Mark Some “Firsts”]

The design could help keep both the sensor and shutter protected. However, anytime something is added to a camera, there’s always the chance for failure. Could a camera drop break the mechanism and leave the cap closed even with a lens on? Would the cap increase reliability by protecting the shutter and sensor, or decrease reliability by adding one more thing that could potentially break?

Of course, just because the patent exists doesn’t mean the technology will one day exist. Many patents are ideas that never come to fruition. But, looking at a company’s patents can provide some clues about what the company is researching.