(under subclass 200) Subject matter in which the photocell is built into a device specific to an art other than the photocell art, and in which the utility of the art device is not destroyed by removal of the photocell.
(1) Note. As an example, a refrigerator which is provided with a photocell controlled defrosting device, in which the photocell senses excessive frost, is found in this subclass, if within the definition of superior subclass 200, since the photocell is (1) built into the refrigerator which (2) is an art device and which (3) has utility if the photoelectric cell is removed. Generally, the patents in this subclass are cross references, as there are few art devices which are not elsewhere provided for.