US PATENT CLASS 349
Class Notes


Current as of: June, 1999
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349 /   HD   LIQUID CRYSTAL CELLS, ELEMENTS AND SYSTEMS



DEFINITION

Classification: 349/

This is the generic class for cells, elements, and systems which include molecules of a material having both liquid and crystalline properties. Elements or systems included in this

class are those which have a significant liquid crystal cell detail or liquid crystal response or properties, and in which the liquid crystal controls or changes the optical properties of electromagnetic radiation such as direction, phase, amplitude, frequency, or polarization state. This class also provides for nominal manufacturing methods for producing significant liquid crystal cell structure.

LINES WITH OTHER CLASSES

If the liquid crystal cell is an insignificant part of a system, or if there is no detail of the liquid crystal cell in the system, the apparatus should not be classified here.

Nominal manufacturing processes for producing significant liquid crystal cell structure, or nominally described "providing processes" that can only be classified by liquid crystal device structure are proper for Class 349. Processes having significant manufacturing steps for producing liquid crystal devices are provided in various manufacturing classes, depending on the steps or combination of steps involved in the process. While plural nominal manufacturing steps are considered significant manufacturing--placing the original in other manufacturing classes, a mandatory cross to this class is required if significant liquid crystal structure is present. See the SEARCH CLASS notes for some examples of manufacturing classes that provide for manufacture of liquid crystal devices.

Liquid crystal compositions with no more than nominal cell structure are excluded from this class; instead see elsewhere. In this case, nominal cell structure refers to a broad recitation of substrates, electrodes (or conductive plates or electrical excitation means), alignment layers, a seal, spacers, and polarizers. (See References to Other Classes, below.)

Driving waveforms and external driving circuitry for the liquid crystal are excluded from this class (see References to Other Classes, below). When the driving is in the context of a television, proper classification is elsewhere.

Electrooptic devices using materials other than liquid crystals and optical elements separate from liquid crystal devices are excluded from this class. (See References to Other Classes, below.)

Nominal liquid crystal display cell structure with specific chemical composition of nonconducting layers other than the liquid crystal are excluded from this class. (See References to Other Classes, below.) REFERENCES TO OTHER CLASSES

SEE OR SEARCH CLASS

29, Metal Working, appropriate subclasses for processes

having combined operations involving metal working, machining, metal fusion bonding, or casting class and treating not provided for in the metal working, machining, welding, or casting classes. Class 29 is also a generic mechanical assembly class.

65, Glass Manufacturing, for processes of, or apparatus for glassworking and/or treating.

117, Single-Crystal, Oriented-Crystal, and Epitaxy Growth Processes; Non-Coating Apparatus Therefor, for processes for growing therein-defined single-crystal of all types of materials and by all techniques, including epitaxy.

156, Adhesive Bonding and Miscellaneous Chemical Manufacture, as the generic class for the adhesive joining of parts and as the generic class for manufacturing processes involving a chemical reaction.

174, Electricity: Conductors and Insulators, appropriate subclasses for the use of conductors and insulators in general.

204, Chemistry: Electrical and Wave Energy,

155+, for a process of coating involving chemical preparation of a compound or element by application to a base of electrical or wave energy in a magnetic field (but without involving electrolysis as provided for in Class 205), where said base supplies a part or all of the coating (e.g., by conversion at the surface, etc.); subclasses 164+ for a process of coating involving chemical preparation of a compound or element by application of an electrostatic field or electrical discharge to a base which supplies a part or all of the coating; subclasses 471+ for a process of coating by electrophoresis or electro-osmosis; and subclasses 192.12+ for coating by glow discharge deposition (e.g., cathode sputtering, etc.).

205, Electrolysis: Processes, Compositions Used Therein, and Methods of Preparing the Compositions,

80+, for electrolytic coating processes and subclasses 183+, 188+, 191+, and 198+ for processes involving plural coating steps, at least one but not all of which is electrolytic. 216, Etching a Substrate: Processes, for etching processes not otherwise provided for in which one of the manufacturing steps includes a chemical etching or physical solvation, especially

23, for making an article containing a liquid crystal material.

228, Metal Fusion Bonding, appropriate subclasses for processes of metal fusion bonding or welding of metal.

252, Compositions,

299.01+, for liquid crystal compositions with no more than nominal cell structure. (See Lines With Other Classes and Within This Class, above.)

257, Active Solid-State Devices (e.g., Transistors, Solid-State Diodes), appropriate subclasses for the use of a transistor in general.

264, Plastic and Nonmetallic Article Shaping or Treating: Processes, for a process of manufacturing nonmetallic articles by shaping or treating.

313, Electric Lamp and Discharge Devices, appropriate subclasses for use of a particular illumination device in general.

315, Electric Lamp and Discharge Devices: Systems, appropriate subclasses for use of a particular illumination system in general.

324, Electricity: Measuring and Testing,

770, for testing a liquid crystal device for a fault in an individual circuit component. 345, Computer Graphics Processing, Operator Interface Processing, and Selective Visual Display Systems,

89, for producing a greyscale effect in a liquid crystal device; subclasses 90+ for using switching devices in a liquid crystal device; subclass 91 for using diodes or varistor in a liquid crystal device; subclass 93 for the use of a redundancy in liquid crystal device; subclass 97 for use of ferroelectric liquid crystal display elements; subclass 101 for generation of data compensation in response to the temperature of the liquid crystal material; and subclasses 104 and 173+ for use of liquid crystal touch pads.

345, Computer Graphics Processing, Operator Interface Processing, and Selective Visual Display Systems, for driving waveforms and external driving circuitry for liquid crystal. (See Lines With Other Classes and Within This Class, above.)

353, Optics: Image Projectors, appropriate subclasses for projectors in general.

359, Optics: Systems (Including Communication) and Elements,

107, for optical computing without diffraction; subclass 462 for stereoscopic systems; subclass 561 for convolution, cross-correlation, or correlation using a diffraction grating; subclasses 619+ for microlenses with no liquid crystal; and subclasses 630+ for general heads-up display devices.

359, Optics: Systems (Including Communication) and Elements, for electrooptic devices using materials other than liquid crystals and optical elements separate from liquid crystal devices. (See Lines With Other Classes and Within This Class, above.)

361, Electricity: Electrical Systems and Devices,

681, for housing for electronic systems or devices with display support, and subclasses 789+ for the use of flexible circuits.

362, Illumination, appropriate subclasses for illuminating devices in general.

365, Static Information Storage and Retrieval, 108, for a memory for a liquid crystal using a light beam.

395, Information Processing System Organization,

25, for optical systems performing neural network type algorithms.

427, Coating Processes, for general coating processes, including vapor deposition, etc.

428, Stock Material or Miscellaneous Articles,

1.1+, for liquid crystal alignment layers having a particular chemical composition.

428, Stock Material or Miscellaneous Articles,

1, for nominal liquid crystal display cell structure with specific chemical composition of nonconducting layers other than the liquid crystal. (See Lines With Other Classes and Within This Class, above.)

430, Radiation Imagery Chemistry: Process, Composition, or Product Thereof, for process of making radiation images involving chemistry.

438, Semiconductor Device Manufacturing: Process, especially

27+, for methods of packaging a semiconductor electronic device having an additional optical component and subclass 30 for methods of making a semiconductor electronic device including a liquid crystal optical component.

445, Electric Lamp or Space Discharge Component or Device Manufacturing, particularly see 24, Note (1) for a liquid crystal display device.

708, Electrical Computers: Arithmetic Processing and Calculating,

191, 816, and 831 for electro-optical data processing systems.

GLOSSARY:

CELL*

For the purpose of this class, a cell is the minimum combination of elements necessary to physically contain an entire liquid crystal layer given a stimulus or excitation. In a matrix addressed liquid crystal device, a single pixel is not a cell.

EXCITATION*

For the purpose of this class, excitation is a force or energy which selects the state of the liquid crystal material.

LAYER*

For the purpose of this class, a layer is a periodic discontinuous material or materials within a single plane having a single function, or a continuous material having one or more functions.

SUBSTRATE* For the purpose of this class, substrate is a flexible or rigid member which provides structural support in a cell.