DIFF Subgroup
G03B 21/11 for microfilm reading
Introduced: September 1968
Full Title
Full titles differ between systems:
IPC:
Projectors or projection-type viewers; Accessories therefor > Projectors with built-in or built-on screen > for microfilm reading
CPC:
Projectors or projection-type viewers; Accessories therefor (devices for changing pictures G03B23/00) > Projectors with built-in or built-on screen > for microfilm reading
Of 3 combined children, 0 exist in both systems.
3 codes are CPC-only extensions.
Child Classifications
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