A CMOS image sensor that employs a vertically integrated double junction photodiode structure is presented. This allows colour imaging with only two, wider bandwidth, filters. The sensor uses a 184 x 154 6-transistor pixel array at a 9.6 µm pitch. Results of the device characterisation, and colour image reconstruction using the prototype sensor, are presented. 1 Introduction Conventional CMOS ... [Show full abstract] colour image sensors employ a standard n+/p diode or photo-gate as the photo-sensing element in an integrating active pixel com-bined with an array of 3 colour filters, often RBG filters arranged in a Bayer pattern. In a previous paper , an alternative pixel structure was described, in which a double junction structure was integrated with active pixel circuitry. Such a sensor has the advantage that a reduced number of colour filters (in this case two) can be used above the pixel array, which results in a more efficient collection of the incident light, and also an equal sampling of all the colour signals in the spatial domain. In this paper, a full CMOS image sensor based on this approach is presented and the colour imaging per-formance is described.