In this patent application (2025-023282), Canon is looking to make the power zoom motors much smaller for future lenses. Canon is exploring using 1, 2, or even more voice coil motors to move the elements necessary to zoom the lens.
According to Canon, the problem they are grappling with is making these small enough not to interfere with autofocus motors. Thus, they have to increase the size and weight of the lens to support both functions. If the motors are small enough, then Canon can make them so they move in groups independently without increasing the lens’s overall size.
Canon’s problem is described here. This is what they are looking to resolve.
Patent document 1 [prior patent] discloses a lens device having an optical system consisting of five lens groups, namely, a first lens group, a second lens group, a third lens group, a fourth lens group, and a fifth lens group, in order from the object side to the image side. Patent document 1 also discloses that a third lens group is driven by a third group motor to perform electric zoom (power zoom), and a focusing motor (voice coil motor) is used to drive the second lens group to perform focusing.
However, if the configuration of Patent document 1 is adopted in a lens device that drives the second lens group to perform electric zoom, the movement stroke of the second lens group may cause the motor that drives the second lens group to interfere with the first lens group or the holding frame that holds the first lens group. On the other hand, if the motor is arranged to avoid such interference, the radial size of the lens device will become large.
In this diagram, the two motors are 20b and 20c. Canon is attempting to arrange these motors so that they do not interfere with lens group L1 and its holding frame (11).
Canon discusses this zoom motor arrangement, which has one, two, or even more motors to move the lens groups necessary.
However, this embodiment is not limited to a configuration having two voice coil motors, and can be applied to a configuration having three or more voice coil motors.
Will we see a better power zoom lens arrangement in the future? Canon’s current power zoom implementations are clunky, which would be a welcome change.
As with all patent applications, this one examines Canon’s research and may not result in a product.
Japan Patent Application 2025-023282
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