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公开(公告)号：KR830001427A
公开(公告)日：1983-07-25
申请号：KR770000514
申请日：1977-02-28
Applicant: RCA CORP
Inventor： RAST ROBERT MORGAN
Abstract: Television tuning apparatus includes first phase locked loop configuration for tuning local oscillator to normal frequency appropriate for converting standard radio frequency carrier allocated to selected channel to predetermined intermediate frequency and second phase locked loop configuration for tuning local oscillator to minimize any deviation between actual frequency of I.F picture carrier and its normal frequency which may occur.
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公开(公告)号：FI65877C
公开(公告)日：1984-07-10
申请号：FI770535
申请日：1977-02-18
Applicant: RCA CORP
Inventor： RAST ROBERT MORGAN
Abstract: Television tuning apparatus includes a first phase locked loop configuration for tuning a local oscillator to a nominal frequency appropriate for converting a standard radio frequency carrier allocated to a selected channel to a predetermined intermediate frequency (e.g., 45.75 MHz) and a second phase locked loop configuration for tuning the local oscillator to minimize any deviation between the actual frequency of the I.F. picture carrier and its nominal frequency which may occur, for example, because the receiver is coupled to a distribution system utilizing frequency conversion apparatus which provides nonstandard radio frequency carriers arbitrarily near respective standard frequency carriers. The two phase locked loop configurations include common elements and control apparatus to selectively initiate the operation of one loop while inhibiting the operation of the other in accordance with a predetermined tuning algorithm.
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公开(公告)号：AU4683479A
公开(公告)日：1979-11-15
申请号：AU4683479
申请日：1979-05-07
Applicant: RCA CORP
Inventor： RAST ROBERT MORGAN
IPC: H03J7/28 , H03J5/00 , H03J5/02 , H03J7/06 , H03L7/12 , H03L7/18 , H04N5/50 , H03B3/06 , H04B1/34
Abstract: A phase locked loop tuning system for a television receiver includes a reference oscillator, a reference divider for dividing the frequency of the output signal of the reference oscillator, a voltage controlled local oscillator, a prescaler for dividing the frequency of the output signal of the local oscillator by a predetermined factor, a programmable divider for dividing the frequency of the output signal of the prescaler by a factor determined by the presently selected channel, a phase comparator for generating a series of pulses representing the phase and frequency relationships between the output signal of the reference divider and the output signal of the programmable divider and a low pass filter for deriving a control voltage for the local oscillator in response to the pulses generated by the phase comparator. The pulses generated by the phase comparator have polarities and widths dependent on the sense of the phase and/or frequency differences between the output signals of the reference divider and the programmable divider. A lock detector determines whether the pulses generated by the phase comparator have widths less than a first predetermined width at the end of a predetermined time. If the output signal of the prescaler has an incorrect frequency in response to a temporary malfunction of a component within the loop, the pulses generated by the phase comparator will not have widths less than the first predetermined width. In response to this occurrence, a mode switch decouples the pulses generated by the phase comparator from the low pass filter and couples pulses having a predetermined duty cycle, a predetermined repetition rate and the opposite polarity to the low pass filter instead. When the lock detector determines the first time one of its output pulses has a width less than a second predetermined width, narrower than the first, the pulses generated by the phase comparator are again coupled to the low pass filter.
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公开(公告)号：DE2919071A1
公开(公告)日：1979-11-22
申请号：DE2919071
申请日：1979-05-11
Applicant: RCA CORP
Inventor： RAST ROBERT MORGAN
IPC: H03J7/28 , H03J5/00 , H03J5/02 , H03J7/06 , H03L7/12 , H03L7/18 , H04N5/50 , H03B3/04 , H03J5/14
Abstract: A phase locked loop tuning system for a television receiver includes a reference oscillator, a reference divider for dividing the frequency of the output signal of the reference oscillator, a voltage controlled local oscillator, a prescaler for dividing the frequency of the output signal of the local oscillator by a predetermined factor, a programmable divider for dividing the frequency of the output signal of the prescaler by a factor determined by the presently selected channel, a phase comparator for generating a series of pulses representing the phase and frequency relationships between the output signal of the reference divider and the output signal of the programmable divider and a low pass filter for deriving a control voltage for the local oscillator in response to the pulses generated by the phase comparator. The pulses generated by the phase comparator have polarities and widths dependent on the sense of the phase and/or frequency differences between the output signals of the reference divider and the programmable divider. A lock detector determines whether the pulses generated by the phase comparator have widths less than a first predetermined width at the end of a predetermined time. If the output signal of the prescaler has an incorrect frequency in response to a temporary malfunction of a component within the loop, the pulses generated by the phase comparator will not have widths less than the first predetermined width. In response to this occurrence, a mode switch decouples the pulses generated by the phase comparator from the low pass filter and couples pulses having a predetermined duty cycle, a predetermined repetition rate and the opposite polarity to the low pass filter instead. When the lock detector determines the first time one of its output pulses has a width less than a second predetermined width, narrower than the first, the pulses generated by the phase comparator are again coupled to the low pass filter.
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Patent Agency Ranking
公开(公告)号：MY8500716A
公开(公告)日：1985-12-31
申请号：MY8500716
申请日：1985-12-30
Applicant: RCA CORP
Inventor： RAST ROBERT MORGAN
Abstract: A phase locked loop tuning system for a television receiver includes a reference oscillator, a reference divider for dividing the frequency of the output signal of the reference oscillator, a voltage controlled local oscillator, a prescaler for dividing the frequency of the output signal of the local oscillator by a predetermined factor, a programmable divider for dividing the frequency of the output signal of the prescaler by a factor determined by the presently selected channel, a phase comparator for generating a series of pulses representing the phase and frequency relationships between the output signal of the reference divider and the output signal of the programmable divider and a low pass filter for deriving a control voltage for the local oscillator in response to the pulses generated by the phase comparator. The pulses generated by the phase comparator have polarities and widths dependent on the sense of the phase and/or frequency differences between the output signals of the reference divider and the programmable divider. A lock detector determines whether the pulses generated by the phase comparator have widths less than a first predetermined width at the end of a predetermined time. If the output signal of the prescaler has an incorrect frequency in response to a temporary malfunction of a component within the loop, the pulses generated by the phase comparator will not have widths less than the first predetermined width. In response to this occurrence, a mode switch decouples the pulses generated by the phase comparator from the low pass filter and couples pulses having a predetermined duty cycle, a predetermined repetition rate and the opposite polarity to the low pass filter instead. When the lock detector determines the first time one of its output pulses has a width less than a second predetermined width, narrower than the first, the pulses generated by the phase comparator are again coupled to the low pass filter.
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公开(公告)号：AU540791B2
公开(公告)日：1984-12-06
申请号：AU4683479
申请日：1979-05-07
Applicant: RCA CORP
Inventor： RAST ROBERT MORGAN
Abstract: A phase locked loop tuning system for a television receiver includes a reference oscillator, a reference divider for dividing the frequency of the output signal of the reference oscillator, a voltage controlled local oscillator, a prescaler for dividing the frequency of the output signal of the local oscillator by a predetermined factor, a programmable divider for dividing the frequency of the output signal of the prescaler by a factor determined by the presently selected channel, a phase comparator for generating a series of pulses representing the phase and frequency relationships between the output signal of the reference divider and the output signal of the programmable divider and a low pass filter for deriving a control voltage for the local oscillator in response to the pulses generated by the phase comparator. The pulses generated by the phase comparator have polarities and widths dependent on the sense of the phase and/or frequency differences between the output signals of the reference divider and the programmable divider. A lock detector determines whether the pulses generated by the phase comparator have widths less than a first predetermined width at the end of a predetermined time. If the output signal of the prescaler has an incorrect frequency in response to a temporary malfunction of a component within the loop, the pulses generated by the phase comparator will not have widths less than the first predetermined width. In response to this occurrence, a mode switch decouples the pulses generated by the phase comparator from the low pass filter and couples pulses having a predetermined duty cycle, a predetermined repetition rate and the opposite polarity to the low pass filter instead. When the lock detector determines the first time one of its output pulses has a width less than a second predetermined width, narrower than the first, the pulses generated by the phase comparator are again coupled to the low pass filter.
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公开(公告)号：AU2248077A
公开(公告)日：1978-08-31
申请号：AU2248077
申请日：1977-02-21
Applicant: RCA CORP
Inventor： RAST ROBERT MORGAN
Abstract: Television tuning apparatus includes a first phase locked loop configuration for tuning a local oscillator to a nominal frequency appropriate for converting a standard radio frequency carrier allocated to a selected channel to a predetermined intermediate frequency (e.g., 45.75 MHz) and a second phase locked loop configuration for tuning the local oscillator to minimize any deviation between the actual frequency of the I.F. picture carrier and its nominal frequency which may occur, for example, because the receiver is coupled to a distribution system utilizing frequency conversion apparatus which provides nonstandard radio frequency carriers arbitrarily near respective standard frequency carriers. The two phase locked loop configurations include common elements and control apparatus to selectively initiate the operation of one loop while inhibiting the operation of the other in accordance with a predetermined tuning algorithm.
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