Patent ID: 7071608

Claim:
An image display device comprising: a face substrate which has anodes and phosphors formed on an inner surface thereof: a back substrate, which has: a plurality of cathode lines which extend in one direction and are arranged in parallel in another direction which intersects one direction, which cathode lines include electron sources; control electrodes which are arranged to face the cathode lines in a non-contact manner and include a plurality of electron passing holes which allow electrons emitted from the electron sources to pass therethrough to an inner surface side of the face substrate in regions which respectively face the electron sources and control an emission quantity of electrons emitted from the electron sources; and acceleration electrodes which face the control electrodes in a non-contact manner, include a plurality of electron passing holes which allow the electrons which pass through the electron passing holes formed in the control electrodes to pass therethrough in regions which respectively face the respective electron passing holes formed in the control electrodes and which accelerate the electrons which pass through the electron passing holes on an inner surface thereof; said back substrate being disposed to face the face substrate with a given distance therebetween; and a frame body which is inserted between the face substrate and the back substrate while surrounding a display region so as to maintain a given distance between the face substrate and the back substrates; wherein assuming a distance between the electron sources and the control electrodes as Lkg, a distance between the control electrodes and the acceleration electrodes as L 12 , a thickness of the electron passing holes formed in the control electrodes as Tgl and a short diameter of the electron passing holes formed in the control electrodes as FGI, the acceleration electrodes satisfy the relationship (Lkg+Tgl+L 12 /2)/FGI≧0.25; assuming a thickness of the electron passing holes formed in the acceleration electrodes as Tg 2 and a short diameter of the electron passing holes of the acceleration electrodes as FG 2 , the acceleration electrodes satisfy the relationship Tg 2 min≦Tg 2 ≦Tg 2 max and the relationship Tg 2 min=2.98FG 2 −0.04; assuming FG 2 <0.109, the acceleration electrodes satisfy the relationship Tg 2 max=0.02/(0.115−FG 2 )−0.06; and assuming FG 2 ≧0.109, the acceleration electrodes satisfy the relationship Tg 2 max=0.03/(FG 2 −0.1)+0.045.