polight-tlens_x_vcm

TLens® compared to VCM

Voice Coil Motor (VCM) is widely used today in camera modules. However, the poLight TLens® technology out-compete more or less all capabilities of traditional VCMs and a change from old VCM technology to new poLight based technology is foreseen for both Smartphones, accessories/wearbales as well as for demanding industry applications. The fundamental structure of the TLens is very different to the VCM technology, were the TLens extremely quickly quickly change the shape of the lens and thereby by the optical characteristics while the VCM technology moves the full lens package to create focus.


The video below illustrates the difference between the two technologies. On the left hand side, the advantages of the TLens can be cleary seen, extremely quick focus and no “Field of View ” variation. The phone used is a mid-tier phone with the TLens mounted on a fixed focus camera and with a contrast based auto-focus algorithm.

The right hand video shows a high-end smartphone with a VCM including PDAF. Please notice the significant lower speed and the some times inability to focus at all, as well as the “pumping effect” due to the use of VCM technology.

The video clearly illustrates the paramount advantages the new TLens teachnology can bring to the camera experience in a smartphone.

Typical Characteristics (1/4” sensor)


  •  
  • TLens®
  • VCM
  • Response time
  • 1 mS
  • 5 to 15 mS
  • Power consumption
  • <5mW
  • 220 mW
  • Field of view
  • No AF pumping
  • AF pumping
  • Smallest Footprint (typical 1/4′ sensor)
  • 6×6 mm
  • >7.5×7.5 mm
  • Magnetic Interference
  • No
  • Yes

 

The  TLens® (the Tunable Lens) is not just a replacement of traditional VCM technology for Auto Focus, it enables a range of totally new experiences, use cases and ways to build innovation and hence strengthen your differentiation. Some of the unique capabilities of the TLens® include:

  • Extremely quick focus – enabling to take several images and combine to one, “All-in-Focus” or grab the moment with instant focus far beyond competing technologies. This unique feature may be used both for back/main cameras as well front facing cameras. The TLens® is here up to 10 times quicker.
     
  • Constant field of view – this means that the zoom effect is not seen when focusing is changing, unlike VCM. This will give a smooth and accurate focus during image and video recording. Further it will significantly reduce complexity in image stitching and bracketing which is relevant for both single- and multi-camera systems.
     
  • High optical axis stability – by design TLens® has high optical axis stability and is not affected by gravity, thermal- and mechanical shock unlike VCM. This imply no need for complex calibration procedures, gives stable behavior with respect to enviorment over the liftetime, resulting in less complex manfucturing process and higher image quality over time. From an application point of view this will significantly reduce complexity in image stitching and bracketing for both single- and multi-camera systems.
     
  • Extremely low power consumption – important for new applications in both smartphones and wearables as well as for industry applications where low power consumption is a requirement. In addition the low power consumtion, unlike VCM, focusing will not increase the temperature of the image sensor resulting in better image quality.
       
  • More efficient manufacturing of camera module with AF – packaged TLens® will enable efficient camera module manufacturing resulting in better yield at camera module level by mimimizing dust contamination compared to VCM which keeps open access to image sensor. Further the integration of camera module with TLens® can easily be fully automated resulting in better yield and more cost effective processes.
     
  • Ease integration of camera in phone – the small footprint makes a TLens® based camera esier to fit in the phone – front and back. Also due to no magents and coil the interference issues will dissaper with a TLens® implementation.
     
  • Enabler for Dual/multi Cam implementation – The eco-system is getting ready for multi camera systems. In this context TLens® will be a key enabler. Due to it´s small footprint the cameras can be placed close together (good for high resolution, extended dynamic range, optical zoom etc), the constant field of view and high optical axis stability (improve image stitching/bracketing computation process) and no electromagnetic cross talk between cameras to not remention the low power consumption as well as the instant focus which will also improve inherently the multi-camera system performance.
     
  • No magnetic interference. Since the TLens® has no coils or springs, the magnetic interference is negligible and two Auto Focus cameras can be close to each other without interference. This provides an enormous design freedom for the OEMs and interference with other coils and RF parts can be minimized.