Global Shutter coming to Canon cameras? [CW3]

Thanks to R. for a batch of interesting Canon patents. This is the first.

A lot of cinematographers would love if Canon eventually implements a global shutter on their cameras. It could happen earlier than some people might think. At least there is a Canon patent (US9018722B2) for a technology that clearly refers to a global shutter.

The global electronic shutter function refers to a function of starting and terminating accumulation of photoelectric charges at the same timings in a plurality of pixels arranged in a matrix form. In order to perform the global electronic shutter function, each pixel of a solid-state image pickup device has a photoelectric conversion element and a charge holding part that holds charges generated through photoelectric conversion for a predetermined period. In the solid-state image pickup device having the global electronic shutter function, each charge holding part holds charges for a period from when accumulation of photoelectric charges is terminated to when the charges are read out. If charges generated in parts other than the photoelectric conversion element flow into the charge holding part during this period, the charges may become a noise signal, and consequently degrade the image quality. To cope with such an undesirable charge inflow, Japanese Patent Laid-Open No. 2007-115803 discloses a configuration in which a second gate electrode of polysilicon is formed so as to be stacked above a first gate electrode and cover the charge holding part in order to block incident light. The second gate electrode described in Japanese Patent Laid-Open No. 2007-115803 prevents light from coming into the charge holding part and consequently suppresses generation of charges in parts other than the photoelectric conversion element, thereby suppressing image quality degradation.

As usual, patent literature is pretty complex. More about the technology…

According to an aspect of the present disclosure, there is provided a method for manufacturing a solid-state image pickup device including a pixel portion in which a plurality of pixels each including a photoelectric conversion element and a transistor are arranged, and a peripheral circuit portion in the vicinity of the pixel portion and including a transistor. The method includes: forming gate electrodes of the transistors in the pixel portion and the peripheral circuit portion; forming a first insulating film in the pixel portion and the peripheral circuit portion; forming a second insulating film above the first insulating film in the pixel portion and the peripheral circuit portion; etching the second insulating film in the photoelectric conversion elements; forming a metal film on the etched second insulating film in the photoelectric conversion elements and on the second insulating film in the peripheral circuit portion; and removing the metal film in the peripheral circuit portion, and forming light-shielding films from the metal film in the photoelectric conversion elements.

To be honest, I think Canon has to feature global shutter on some of their pro gear. This patent may point in the right direction. Hard to say when we will see a global shutter enabled Canon camera. Given the secrecy of Canon labs, it’s difficult to make a prevision, and most likely we will know in the very last minute. No one has foreseen today’s announcement of a Canon 250 megapixel sensor. Figure out.

You can download the patent literature here, and are more than welcome to help me break it down :-) What do you think?