Vacuum tube and vacuum tube manufacturing apparatus and method

Abstract

With respect to a vacuum tube having a reduced pressure vessel containing an electric discharge gas sealed therein, problems such as the lowering of discharge efficiency owing to an organic material, moisture or oxygen remaining in the reduced pressure vessel have taken place conventionally. It has been now found that the selection of the number of water molecules, the number of molecules of an organic gas and the number of oxygen molecules remaining in the reduced pressure vessel, in a relation with the number of molecules of a gas contributing the electric discharge allows the reduction of the adverse effect by the above-mentioned remaining gas. Specifically, the selection of the number of molecules of the above electric discharge gas being about ten times that of the above-mentioned remaining gas or more can reduce the adverse effect by the above-mentioned remaining gas.

1 . A vacuum tube manufacturing apparatus comprising a reduced-pressure vessel connecting portion, a gas exhaust mechanism connected to said reduced-pressure vessel connecting portion, and a gas supply mechanism connected to said reduced-pressure vessel connecting portion, said vacuum tube manufacturing apparatus characterized in that an inert gas supply mechanism is disposed on a reduced-pressure vessel side of said gas exhaust mechanism. 
     
     
         2 . A vacuum tube manufacturing apparatus according to  claim 1 , characterized in that said gas exhaust mechanism is an exhaust pump and an inert gas supply mechanism is disposed on an exhaust side of said exhaust pump. 
     
     
         3 . A vacuum tube manufacturing apparatus according to  claim 1 , characterized in that said gas exhaust mechanism comprises a pressure-reducing exhaust mechanism and a filling exhaust mechanism. 
     
     
         4 . A vacuum tube manufacturing apparatus according to  claim 3 , characterized by having a first gas flow control mechanism on a gas supply mechanism side of said reduced-pressure vessel connecting portion, wherein said filling exhaust mechanism comprises a second gas flow control mechanism. 
     
     
         5 . A vacuum tube manufacturing apparatus according to  claim 4 , characterized in that said first gas flow control mechanism includes at least an orifice. 
     
     
         6 . A vacuum tube manufacturing apparatus according to  claim 4 , characterized in that said second gas flow control mechanism includes at least an orifice. 
     
     
         7 . A vacuum tube manufacturing apparatus according to  claim 1 , characterized in that said gas supply mechanism has at least a pressure control mechanism adapted to control a pressure inside the reduced-pressure vessel. 
     
     
         8 . A vacuum tube manufacturing apparatus according to  claim 1 , characterized in that said gas supply mechanism has at least a flow rate control mechanism adapted to control a flow rate of a gas flowing in said reduced-pressure vessel connecting portion. 
     
     
         9 . A vacuum tube manufacturing apparatus according to  claim 1 , characterized by comprising a second reduced-pressure vessel connecting portion different from said reduced-pressure vessel connecting portion, an inert gas supply mechanism connected to said second reduced-pressure vessel connecting portion, and a back diffusion prevention mechanism connected to said second reduced-pressure vessel connecting portion. 
     
     
         10 . A vacuum tube manufacturing apparatus according to  claim 1 , characterized in that said back diffusion prevention mechanism is a pipe or an orifice. 
     
     
         11 . A vacuum tube manufacturing apparatus according to  claim 10 , characterized in that a gas flow rate flowing in said pipe is a flow rate for suppressing invasion of moisture into said gas supply mechanism from said reduced-pressure vessel connecting portion. 
     
     
         12 . A vacuum tube manufacturing apparatus according to  claim 10 , characterized in that the gas flow rate flowing in said pipe falls within the range of 1 SCCM to 1000 SCCM when the reduced-pressure vessel is not connected. 
     
     
         13 . A vacuum tube manufacturing apparatus according to  claim 1 , characterized in that a moisture concentration measured at the first reduced-pressure vessel connecting portion is 1 ppm or less. 
     
     
         14 . A vacuum tube manufacturing apparatus according to  claim 1 , characterized in that a surface adapted to contact the gas contains a metal oxide having chromium oxide or aluminum oxide as a main component. 
     
     
         15 . A fluorescent tube manufactured by using the vacuum tube manufacturing apparatus according to  claim 1 . 
     
     
         16 . A cold cathode tube manufactured by using the vacuum tube manufacturing apparatus according to  claim 1 . 
     
     
         17 . A deuterium discharge tube manufactured by using the vacuum tube manufacturing apparatus according to  claim 1 . 
     
     
         18 . An electron beam tube manufactured by using the vacuum tube manufacturing apparatus according to  claim 1 . 
     
     
         19 . An X-ray generating tube manufactured by using the vacuum tube manufacturing apparatus according to  claim 1 . 
     
     
         20 . An ultraviolet generator manufactured by using the vacuum tube manufacturing apparatus according to  claim 1 . 
     
     
         21 . A static electricity neutralizer manufactured by using the vacuum tube manufacturing apparatus according to  claim 1 . 
     
     
         22 . A vacuum tube manufacturing method comprising a step of attaching a reduced-pressure vessel to a vacuum tube manufacturing apparatus, a step of exhausting a gas in said reduced-pressure vessel, a step of filling at least a discharge gas into said reduced-pressure vessel, and a step of separating said reduced-pressure vessel filled with the discharge gas from said vacuum tube manufacturing apparatus, said vacuum tube manufacturing method characterized in that a dry inert gas is caused to flow in a reduced-pressure vessel connecting portion of said vacuum tube manufacturing apparatus before said reduced-pressure vessel is attached thereto. 
     
     
         23 . A vacuum tube manufacturing method comprising a step of attaching a reduced-pressure vessel to a vacuum tube manufacturing apparatus, a step of exhausting a gas in said reduced-pressure vessel, a step of filling at least a discharge gas into said reduced-pressure vessel, and a step of separating said reduced-pressure vessel filled with the discharge gas from said vacuum tube manufacturing apparatus, said vacuum tube manufacturing method characterized in that the step of exhausting the gas in said reduced-pressure vessel is specified by carrying out combination of filling and exhaust of a dry gas a plurality of times. 
     
     
         24 . A vacuum tube manufacturing method according to  claim 23 , characterized in that the step of exhausting the gas in said reduced-pressure vessel is carried out by raising said reduced-pressure vessel to a temperature higher than a room temperature.