Color pickup tubes containing stripe filters

Claim 1

In a colour pickup tube containing a stripe filter and of the type comprising an optical system mounted on the light receiving portion of said tube and including a photoelectric converting member for converting light from an object into an electric signal; an electron gun assembly, and an envelope containing said electron gun assembly in one end thereof, the opposite end of said envelope being sealed with a first light transmissive substrate, the inner surface of said substrate being provided with respectively with said stripe filter, a transparent conductive film and said photoelectric converting member, and sealed within said envelope, said optical system being mounted to the outer surface of said first light transmissive substrate, the improvement wherein said optical system provides a continuous axial path without refractive surface discontinuity and comprises an outer plate which is an optical low pass filter, a second light transmissive substrate having a color compensating filter on one surface, said one surface bonded to a surface of said plate, said second light transmissive substrate having the other surface including a black level stablizing black mask thereon bonded to the outer surface of said first light transmissive substrate, each bonded interface being provided with means bonding said substrates with material having substantially the same refractive index which is photochemically stable.