US 7728895

Patent Overview — US 7,728,895 B2

Title: Solid-state image sensing device having shared floating diffusion portions

Patent number: US 7,728,895 B2
Application number: US 11/792,856
Filing date: 2006-07-11
Priority date: 2005-12-26 (listed as an assumption)
Publication date: 2010-06-01
Original assignee: Panasonic Corp. (later recorded as Panasonic Corporation); current assignee listed as Collabo Innovations Inc
Inventors: Shouzi Tanaka, Ryouhei Miyagawa, Kazunari Koga, Takahiro Muroshima, Kenji Watanabe

Purpose (per the text): To realize a miniaturized, highly sensitive solid-state image sensing device in which, when multiple photodiode (PD) portions share a floating diffusion (FD) portion, the FD portion occupies a small proportion of the pixel area. The text states that in prior arrangements a shared FD portion was almost the same size as one provided for a single PD portion, leaving insufficient area for the PD portions.

Plain-language scope: The device has unit pixels arranged in rows and columns, each outputting a pixel signal according to incident light, plus floating diffusion portions that receive those signals. Every two unit pixels share one FD portion, and those two pixels are located in adjacent rows and adjacent columns — i.e., the FD is arranged diagonally relative to the pixels, rather than in parallel with them, reducing the area the FD occupies and increasing the PD proportion. Each unit pixel includes a photoelectric conversion portion and a transfer read-out transistor, with the FD portion serving as that transistor's drain region. A pixel amplifier transistor reads out the signal accumulated in the FD portion. Adjacent FD portions in the row direction may be electrically connected and share a common pixel amplifier transistor. Vertical signal lines are provided per column, with odd/even row signals distributed across adjacent lines. A signal processing section successively reads out pixel signals to form a one-row image sensing signal, driven by a horizontal scan circuit that outputs horizontal drive signals at different timings for even-numbered versus odd-numbered rows.

Source: https://patents.google.com/patent/US7728895/en

What this excerpt does not establish: It is an incomplete excerpt. It omits the full claims, detailed embodiments, drawings, and most of the description, so claim scope cannot be fully assessed. Dates, assignee listings, and legal status (including the 2027-08-07 adjusted expiration) are expressly flagged in the source as assumptions, not legal conclusions.