(under the class definition) Discharge devices which have a thermionic or emissive cathode.
(1) Note. This subclass is the residual subclass providing for discharge devices which have thermionic or emissive cathodes which are not provided for in the above subclasses. This subclass does not contain cross-references of devices classified in the preceding subclasses where the sole novelty in the cathode is in the structure or the cathode. For such cross-references, see subclasses 337+ where the cathode is an indirectly heated cathode, 341+, where the cathode is a filament or resistance heated electrode, 346 for cathodes which contain or are coated with electron emissive material. This subclass does not contain cross-references of devices classified in the preceding subclasses where the sole novelty in the cathode is the composition of the cathode. For such cross-references, see the classes referred to in the class definition. Neither does this subclass contain cross-references to patents where the sole novelty is in the supporting and/or spacing structure for either the cathode or the cathode and the other electrodes. The search should include the subclasses above which provide for special types of discharge devices where a specific type of discharge device is involved. For example, cathode-ray tubes with thermionic or emissive cathodes are classified in subclasses 364+ above. Where the discharge device is provided for in some general subclass, such as subclasses 11+ (with temperature modifier) and structure of the cathode is claimed in addition to that provided for in either the general or specific subclasses preceding this subclass, the patent is cross-referenced into this subclass. See the search notes
below for a reference to some of the subclasses which provide for discharge devices having a thermionic or emissive cathode.
SEE OR SEARCH THIS CLASS, SUBCLASS:
1+, for plural unit discharge devices which have at least two cathodes and at least one anode for each cathode.
16, for discharge devices which have a liquid electrode and an electric heater for the liquid electrode.
37+, where the cathode is provided with means other than the mere filament or heater for modifying the temperature of the cathode (e.g., a heat shield). 103+, for secondary emitter discharge devices (e.g., electron multiplier) which have emissive cathodes.
163+, for discharge devices which have a liquid (e.g., mercury cathode) 616, 627+ and 630 for discharge devices which contain a gas or vapor and which have a thermionic or emissive cathode. See subclass 616 where the device is provided with means to shield the cathode from positive ion bombardment, subclasses 627+ where the device has a heated or thermionic cathode, and subclass 630 for the miscellaneous gas or vapor discharge devices with emissive cathodes.
233, for discharge devices which are defined by the degree of vacuum and which include a thermionic or emissive cathode.
244+, for discharge devices which are provided with means for supporting and/or spacing a plurality of electrodes, one of which may be a thermionic or emissive cathode. See (1) Note above.
270, for discharge devices which are provided with means for supporting and/or spacing an indirectly heated cathode. See (1) Note above.
271, for devices having means for supporting and/or spacing a filament. See (1) Note above.
293+, for discharge devices which have a thermionic or emissive cathode and other electrode and an apertured or grid-like electrode interposed between the cathode and the other electrode. See subclass 302 where the discharge device has a plurality of cathodes and subclass 304 where the discharge device is provided with a plural section cathode having the cathode wires parallel to each other.
305, for discharge devices which have a cathode and other electrode which is designed to be used as an anode with respect to the first cathode and to be heated by the electron bombardment from the first cathode, the electrode having another surface which when heated emits electrons to a third electrode, (e.g., cathanode type discharge device).
315+, for incandescent lamps which have a filament or glower.
337+, see (1) Note, above.
341+, see (1) Note, above. 346, see (1) Note, above.
364+, for cathode-ray tubes which have a thermionic or emissive cathode. See subclass 409 where the cathode-ray tube has a plurality of cathodes.
523+, for photosensitive devices which have an emissive cathode.
SEE OR SEARCH CLASS
378, X-Ray or Gamma Ray Systems or Devices,
121+, for X-ray tubes which have a thermionic or emissive cathode.
