Color television camera with a device for additional illumination of signal converting plates of camera tubes

Claim 1

In a color television camera having an image pickup lens system, a plurality of primary color television camera tubes with corresponding signal converting plates, and an optical device for separating an image light beam from said image pickup lens system into primary color images for said camera tubes and for providing an additional illumination of said signal converting plates to suppress the afterglow, said optical device comprising, in combination, a first prism having a light beam input facE and two light beam output faces; and a second prism having two light beam input faces and two light beam output faces; one of said beam output faces of said first prism being provided with a dichroic layer to separate the incoming light beam and mating with a first light beam input face of said second prism; one output face of said second prism being provided with another dichroic layer to further separate the incoming light beam; the output faces of said second prism and the free output face of said first prism being optically coupled with the signal converting plates of respective camera tubes; the second light beam input face of said second prism being disposed opposite to said first light beam input face and directed thereto at such an angle as to project its perpendicular center axis through the mating faces of said prisms at the region of passage of said light beam from said image pickup lens system; and an auxiliary illumination source for transmitting an auxiliary light beam through said second light beam input face of said second prism in the direction of said center axis, whereby the parts of the auxiliary light beam reflected from and passing through said second dichroic layer is traveling in the same direction as the part of the incoming light.