Abstract: A line synchronizing circuit in a picture display device includes a phase discriminator, a loop filter and a line oscillator constituting a control loop for controlling the frequency and/or the phase of the oscillator signal. To reduce the phase error, which occurs after a phase jump in the incoming signal, and to reduce the time in which the error is visible, the loop filter has a first part for supplying a first control signal having a first response time and a second part for supplying a second control signal having a second response time which is shorter than the first response time. The two parts of the loop filter are coupled to the control input of the line oscillator. A switching apparatus selectively couples two parts or the second part, of the loop filter to the output of the phase discriminator.

Abstract: Circuit arrangement in a picture display device, including a video signal processing circuit and a line synchronizing circuit with a clock signal the frequency of which is coupled to the line frequency. To eliminate a ripple, which is present in the control signal for the line generator during the occurrence of the line synchronizing pulses and which causes a disturbance when reading the video information by means of a clock signal, a compensation signal is generated which has the same frequency as the signal from the generator and which is applied to the control input of the generator, the signal at the control input being substantially constant throughout the line period in the synchronous state of the line synchronizing circuit.

Abstract: A line synchronising circuit in a picture display device comprises a phase discriminator, a loop filter and a line oscillator constituting a control loop for controlling the frequency and/or the phase of the oscillator signal. To reduce the phase error, which occurs after a phase jump in the incoming signal, and to reduce the time in which the error is visible, the loop filter has a first part for supplying a first control signal having a first response time and a second part for supplying a second control signal having a second response time which is shorter than the first response time, the two parts of the loop filter being coupled to the control input of the line oscillator, and means for coupling the two parts or the second part, respectively, of the loop filter to the output of the phase discriminator.