The proposed OIS VCM actuator is thinner than a commercial OIS VCM actuator and was verified experimentally with a laboratory-built prototype. The abstract identifies it as a voice coil motor actuator for smartphone cameras, indicating a direct electromagnetic actuator design rather than a geared mechanism.

In this work, an auto-focus actuator moving lens in mobile phone cameras is developed by applying a rotary VCM (voice coil motor). A novel inclined cam structure is used to convert the rotational motion by the VCM into the linear motion of the focusing lens.[2] The new focusing design enables the zero holding current required to maintain the lens module in the focusing position as well as the reduction of the module thickness.[2] This paper presents the theoretical analysis and optimal design for the VCM actuator, cam structure and preload spring.[2]

The incumbent actuator technology for such cameras is the voice coil motor (VCM).[5] However, given the need to control the lens position with a resolution of 1 micron, such suspension mechanisms must account for friction.[5] In particular, high image quality requires the lens motion along the optical axis to be accompanied by minimal parasitic motion in the other degrees of freedom, particularly tilt about axes orthogonal to the optical axis. This requires the suspension mechanism to be stiff to such parasitic motions.[5]

Designing an autofocus camera involves using an autofocus lens which comes in two variants – **liquid lens autofocus, and Voice Coil Motor (VCM) autofocus**.[6] "In a VCM autofocus lens, autofocus is achieved by means of the **mechanical movement of the lens**. A change in position of the lens with respect to the image sensor is required every time the camera needs to change its focal length. **This frequent movement of the lens causes friction**, and hence results in more heat dissipation."[6] Whereas in a liquid lens, autofocus is achieved without mechanical movement of the lens, resulting in much less heat dissipation compared to a VCM lens.[6]

Traditional actuators, such as VCMs, require constant power to maintain the selected f/stop, adding to energy consumption and heat dissipation.[4] SMA’s high force-to-mass ratio enables this capability which is not possible with VCM actuator technology.[4] Figure 1: The mechanical principle of ZHP relies on friction and preload forces (via springs or similar components)… When combined with the high force output of SMA wires, the actuator can overcome the friction to move, then remain stationary when powered off.[4]

"A Voice Coil Motor is a simple type of electric motor which utilises magnets surrounding a coil of wire. Canon has developed a VCM for its lenses as these types of motor **can control the position of lens elements quickly and precisely**." VCMs are used as **linear motors** to drive lens groups directly, rather than through gear trains, for smooth and fast autofocus.[7] Because of their construction, VCMs provide quiet and responsive focusing compared to conventional geared motors.[7]

OIS actuators use a voice coil motor (VCM) that drives the camera's autofocus and image stabilization mechanisms. The article explains that these miniature actuators physically adjust lens placement, again describing a motorized actuator rather than a gear train.

"Utilization of Nikon's exclusive **linear voice coil motor (VCM) for autofocus drive** enables very fast and precise autofocusing and smoother AF."[8] The description emphasizes that the VCM is a **linear motor drive** for autofocus, contrasting it with traditional geared drive systems used in many lenses.[8] Users note the smoothness and speed of VCM-based autofocus, related to the direct-drive nature of the system.[8]

VCM springs are described as a crucial component of smartphone camera modules within the actuator system. They play a key role in automatically focusing the lens and optically stabilizing images when combined with the auto-focus function.

The CLA321-VCM is described as a **voice-coil auto-focus motor for M12 lenses** with specified stroke, current, hysteresis, tilt and life cycle characteristics.[2] The datasheet lists parameters such as **rated stroke**, starting current, hysteresis and maximum lens weight, implying that the lens is moved mechanically over a stroke of several hundred micrometers.[2] The presence of hysteresis and mechanical stroke indicates that the system involves physical motion subject to mechanical effects, not a perfectly frictionless environment.[2]

VCMs are used in smartphones to shift the lens position to autofocus.[7] The direct-drive nature of VCMs eliminates most of the drawbacks of traditional motors, such as backlash, inertia, friction, and rigidity.[7] VCMs provide silent and faster focusing than traditional motors, and this proves to be greatly beneficial in video recording.[7]

The 4-wire SMA actuator design is presented as an alternative to VCM systems for smartphone cameras. The page says SMA technology offers advantages over alternative OIS systems such as VCM, implying that VCM itself is a distinct actuator approach rather than a gear-based assembly.

In vertical camera, all these suspensions are done with springs so they hold it into a position with the resting position in the middle.[8] The coil is acting on the magnet to move towards or against the coil, but if you want longer stroke the spring is not a good solution; therefore you often use ball bearings which are really good and can be very accurate in the linear direction.[8] The drawback is that when you have it powered on and moved to a certain position you need a lot of energy to keep it there, and secondly if you turn the electricity off, which you do when you turn the camera off, the suspension and friction characteristics determine how it returns.[8]

A high performance **voice-coil driven nanopositioning slide** is described for high speed precision applications.[4] "The V-308 nanopositioning linear slide is designed for vertical loads up to 1kg, controlled by a **voice coil linear motor and a frictionless counterbalance**."[4] This shows that while the slide uses a voice coil motor for linear motion, additional mechanical design (a frictionless counterbalance) is specifically employed to minimize friction in the overall system.[4]

An actuator is a component in a camera module that moves the lens up and down or left and right at high speed to focus or stabilize images.[6] Major functions of actuators in camera modules include auto focus (AF) and optical image stabilization (OIS), both of which require precise, repeatable mechanical movement of the lens assembly.[6] These actuators are integrated into the camera module and operate within mechanical guides and suspensions to achieve the necessary motion.[6]

VCM (Voice Coil Motor) RF lenses, offering silent, ultra-precise autofocus. **No gears. No rotation. No mechanical friction.**[3] Instead of gears and mechanical linkages moving your lens elements around, VCM uses **pure electromagnetic force**.[3] When electrical current flows through that coil, this electromagnetic force moves the coil (and whatever lens element is attached to it) in a perfectly straight line along **precision rails**.[3]

The paper proposes a novel voice coil motor actuator for smartphone camera modules and says the system uses an innovative electromagnetic structure to provide five degrees of freedom compensation. The description does not mention gears, and the actuator is framed as a direct electromagnetic module.

Therefore, this paper proposes a novel voice coil motor (VCM) actuator that can supply a 5 degree of freedom (DOF) compensation that consists of three linear movements and two rotational movements for smartphone camera modules.[1] This novel VCM actuator with 5-DOF compensation is realized using an innovative electromagnetic structure.[1] The experimental results verify the robust properties and feasibility of the proposed VCM actuator.[1]

This is called a **voice coil motor** and it's the hidden mechanical trick that actually makes smartphone cameras focus.[7] Instead of **gears or pulleys**, it uses a moving coil inside a magnetic field to physically move the lens module up and down to adjust focus.[7] The lens is suspended on springs and the VCM pulls it closer or pushes it further from the sensor, changing the focal distance.[7]

In this work, an auto-focus actuator moving lens in mobile phone cameras is developed by applying a rotary VCM (voice coil motor).[9] A novel inclined cam structure is used to convert the rotational motion by the VCM into the linear motion of the focusing lens.[9] The actuator uses a preload spring and mechanical cam interface between the rotating VCM and the lens, indicating mechanical contact and potential friction at these interfaces.[9]

A typical voice coil motor consists of a **coil of wire in a magnetic field** that produces a force proportional to current, causing **linear motion** of the coil or attached load. Because the force is applied directly without a rotary-to-linear conversion mechanism, VCMs are classified as **gearless, direct-drive actuators** in many engineering texts. However, in practical assemblies such as camera modules, the moving lens carrier is guided by mechanical structures (springs, flexures, or rails), which introduce some mechanical friction even though no gears are used.

This paper proposes a **voice coil motor (VCM) with a novel electromagnetic structure for smartphone OZ actuators**.[6] A VCM generally consists of a permanent magnet, a coil, and a suspension mechanism that guides the motion of the moving part.[6] Because the actuator involves moving mechanical components guided in a narrow space, issues such as **mechanical wear and friction** must be considered in the design, especially for reliability in smartphone applications.[6]

The lens part contains magnetic coils (VCM actuator?) to shift it forwards or backwards for changing focus (no OIS here, only Auto Focus).[3] The lens assembly includes magnetic coils that adjust the lens position for focusing, and mechanical contacts and resistance changes are observed when the lens is physically moved, suggesting guided mechanical motion with friction.[3] Contacts 5 and 6 show a resistance of about 18 ohms, which changes to 24–28 ohms when the lens is physically moved and then returns, indicating an electromechanical actuator interacting with mechanical guides.[3]

The paper discusses an **on-chip voice coil motor driver for mobile auto-focus camera modules**, focusing on current control and displacement characteristics of the VCM.[9] It models the **displacement change** of the voice coil motor using electrical simulation, reflecting the mechanical motion of the autofocus lens driven directly by the coil and magnet assembly.[9] This reinforces that mobile autofocus systems use VCMs as direct linear actuators for lens movement, with no mention of gears in the drive path.[9]