GB696121A - Improvements in or relating to television and like receivers - Google Patents
Improvements in or relating to television and like receiversInfo
- Publication number
- GB696121A GB696121A GB2148348A GB2148348A GB696121A GB 696121 A GB696121 A GB 696121A GB 2148348 A GB2148348 A GB 2148348A GB 2148348 A GB2148348 A GB 2148348A GB 696121 A GB696121 A GB 696121A
- Authority
- GB
- United Kingdom
- Prior art keywords
- synchronizing
- circuit
- diode
- black
- level
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000002131 composite material Substances 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
- H04N5/16—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level
- H04N5/18—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level by means of "clamp" circuit operated by switching circuit
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Television Receiver Circuits (AREA)
Abstract
696,121. Television. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. July 29, 1949 [Aug. 13, 1948], No. 21483/48. Class 40 (iii). The D.C. restoration circuit in a television receiver is rendered inoperative during the occurrence of synchronizing signals, so that the " black " level of the signals coincides with the " cut-off" " point of the picture reproducing cathode-ray tube for all settings of the receiver gain control, by applying to the said circuit pulses coincident with the synchronizing pulses derived from the part of the signal circuit between the last amplifier and the cathode-ray tube. As shown, negatively-going synchronizing pulses, separated from the composite signal at the anode of the last video amplifier V by means of a diode D<SP>3</SP>, are applied to the anode of the D.C.-restoring diode D<SP>2</SP> to render it non- conducting during the synchronizing periods so that the circuit comprising the elements C<SP>1</SP>, D<SP>2</SP> and R<SP>4</SP> operates to restore the " black " level at the control grid CG of the picture reproducing tube with reference to " back porch " or black level, which occurs for a very short period after the termination of a synchronizing pulse, and not with reference to the peaks of the synchronizing pulses. Diode D<SP>1</SP> biased by means of resistance R<SP>3</SP> operates as a peak " white " limiter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2148348A GB696121A (en) | 1948-08-13 | 1948-08-13 | Improvements in or relating to television and like receivers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2148348A GB696121A (en) | 1948-08-13 | 1948-08-13 | Improvements in or relating to television and like receivers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB696121A true GB696121A (en) | 1953-08-26 |
Family
ID=10163696
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2148348A Expired GB696121A (en) | 1948-08-13 | 1948-08-13 | Improvements in or relating to television and like receivers |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB696121A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3003028A (en) * | 1956-12-15 | 1961-10-03 | Philips Corp | Circuit arrangement for re-introducing the direct current component of a video signal |
-
1948
- 1948-08-13 GB GB2148348A patent/GB696121A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3003028A (en) * | 1956-12-15 | 1961-10-03 | Philips Corp | Circuit arrangement for re-introducing the direct current component of a video signal |
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