A frame assembly can be configured to couple one or more doors to a refrigeration case having an opening. This provides spatially-separated sub-pixels, and a number of the sub-pixels can be addressed in order to provide a grey scale output for each pixel. Typically, The frame member consists of two frame members which are respectively attached to the side frames at the right and left sides, and the structure further comprises a cross beam for coupling the frame members with each other, wherein the cross beam extends in the width direction of the vehicle.