The size of the imaging element written in the specification etc. is not the actual diagonal dimension in notation following the “tube diameter” of the imaging tube age.
For example, 1/2 inch CCD means 「A CCD with the same image size as the image size produced by a 1/2-inch imaging tube」
However, the size will be confirmed with this notation.
If it is a 4: 3 elements, the size will be identified as below.
“CCD Camera image size”