← Back to Patent Explorer
US5003397A Expired / Lapsed US ⏱️ 0.0 years remaining

Television receiver including a tuning circuit which comprises a frequency synthesis circuit

Assignee: US Philips Corp
•
Filing: 1989-07-10
•
Granted: 1991-03-26
•
Expires: 2009-07-10
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract In a television receiver including a frequency synthesis circuit (33) controlled by a phase detection circuit (21), in which an adjustable frequency divider (15) receives a tuning datum which is corrigible by means of an AFC circuit (119, 129), a synchronous video signal detector (57) with a reference signal oscillator (97) are used, while the AFC detector is a counter (119) which is coupled via a measuring gate (115) to an output (99) of the reference signal oscillator, and the measuring gate (115) is operatd by a measuring gate signal having an accurate periodicity being derived from a received television signal, so that a minimum possible number of terminals on an integrated circuit is sufficient.

Inventors

  • 👤 Meye Wink

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 20:18
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/02; H03J7/04; H03J7/06; H03J7/065; H04; H04N; H04N5/00; H04N5/44; H04N5/50

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 177 words
A television receiver including a tuning circuit which comprises a frequency synthesis circuit in which the tuning of a tuning oscillator is obtained by means of a frequency divider which is adjustable by means of a tuning datum, said tuning datum being corrigible by means of a frequency detection circuit when receiving a television signal identified as being correct by an identification circuit, said frequency detection circuit being coupled to an output of an intermediate frequency amplifier, an input of which is coupled to an output of the tuning circuit, characterized in that the frequency detection circuit is a counter which is coupled at least via a measuring gate to an output of a reference signal oscillator which forms part of a phase-coupled loop coupled to an output of the intermediate frequency amplifier, an output of said reference signal oscillator being further coupled to a reference signal input of a synchronous video signal detector while the measuring gate is operable by means of a measuring gate signal synchronized with the line frequency of a received television signal.
Claim 2
Dependent Claim 177 words
A television receiver including a tuning circuit which comprises a frequency synthesis circuit in which the tuning of a tuning oscillator is obtained by means of a frequency divider which is adjustable by means of a tuning datum, said tuning datum being corrigible by means of a frequency detection circuit when receiving a television signal identified as being correct by an identification circuit, said frequency detection circuit being coupled to an output of an intermediate frequency amplifier, an input of which is coupled to an output of the tuning circuit, characterized in that the frequency detection circuit is a counter which is coupled at least via a measuring gate to an output of a reference signal oscillator which forms part of a phase-coupled loop coupled to an output of the intermediate frequency amplifier, an output of said reference signal oscillator being further coupled to a reference signal input of a synchronous video signal detector while the measuring gate is operable by means of a measuring gate signal synchronized with the line frequency of a received television signal.

References Cited (Backward Citations)

US4240115A Cited
US4305157A Cited
US4408349A Cited
US4485404A Cited
US4556988A Cited
US4543614A Cited
US4843636A Cited
US4689685A Cited
US4727591A Cited
US4817195A Cited
US4776038A Cited
US4811096A Cited
US4919640A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-03-25 1994-09-24 1995-03-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-03-25 1998-09-24 1999-03-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-03-25 2002-09-24 2003-03-26 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag