Color transmission system discrimination circuit in television set

In a receiver capable of receiving a plurality of television systems, a color transmission system discrimination circuit is provided, which is capable of exactly and rapidly determining a color transmission system which is being received. The color transmission system discrimination circuit includes: a killer state change detection circuit 23 for detecting a change in three kinds of color killer signals corresponding to a burst signal component in a 90° phase, a burst signal component in a 180° phase, and a SECAM discrimination signal; a sequencer 22 which is driven with an output signal of the killer state change detection circuit 23 and performs the first, second, and third stages in this order respectively for a predetermined period of time; first latch circuits 29 to 31 for latching the color killer signal captured in the first stage; second latch circuits 32 and 33 for latching the color killer signal captured in the second stage; and a discrimination decoder 34 for outputting a discrimination signal of a color system and a discrimination signal of a frequency of a reference sub-carrier signal, based on the color killer signal captured in the third stage and the output signals of the first and second latch circuits 29 to 33.