GB553381A - Improvements in television systems - Google Patents
Improvements in television systemsInfo
- Publication number
- GB553381A GB553381A GB15239/41A GB1523941A GB553381A GB 553381 A GB553381 A GB 553381A GB 15239/41 A GB15239/41 A GB 15239/41A GB 1523941 A GB1523941 A GB 1523941A GB 553381 A GB553381 A GB 553381A
- Authority
- GB
- United Kingdom
- Prior art keywords
- diode
- signals
- resistance
- grid
- voltage
- 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
- 230000004048 modification Effects 0.000 abstract 2
- 238000012986 modification Methods 0.000 abstract 2
- 230000003321 amplification Effects 0.000 abstract 1
- 230000005540 biological transmission Effects 0.000 abstract 1
- 238000003199 nucleic acid amplification method Methods 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
- H04N5/20—Circuitry for controlling amplitude response
- H04N5/202—Gamma control
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Picture Signal Circuits (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
- Microwave Amplifiers (AREA)
- Amplifiers (AREA)
Abstract
553,381. Television. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Nov. 26, 1941, No. 15239. Convention date, Nov. 27, 1940. [Classes 40 (iii) and 40 (v)] A television transmission circuit comprises an etectron discharge device 7 receiving on its control grid 5 signals including picture signals, blanking signals, and a reference voltage, a rectifier 25 in the output circuit of the electron discharge device, and means for applying a predetermined bias to the rectifier so that the signals passed are only those in one direction of polarity from a predetermined value. In the circuit shown in Fig. 1, the image signals are generated in a camera 1 supplied with synchronizing and blanking signals from a generator 9. The signals are amplified by an amplifier 3 and passed to the grid 5 of the electron device 7 through a condenser 8, which also transmits a blanking signal from the generator 9. This generator also supplies the blanking signal to a D.C. insertor circuit 11 which applies a reference bias voltage to the grid 5 of the electron device 7. The anode 17 of the electron device 7 and the cathode 23 of the diode 25 are connected to B+ through an adjustable resistance 21 in series with a fixed resistance 19. The screen grid 15 of the electron device 7 is connected to the same voltage source by the resistance 33. The anode 27 of the diode 25 is also connected to the same source of voltage through a resistance 35 in series with the resistance 33. The junction of the resistances 33, 35 is connected to a voltage regulator comprising a valve 37 in parallel with a condenser 39 and a resistance 41. The output is taken from the anode 27 of the diode to an amplifier 29 followed by a transmitter 31. In a modification, Fig. 4, a second diode 43 is added in the reverse direction in parallel with the diode 25, and an auxiliary valve 53 is inserted in the circuit of the diode 25 to act as a variable impedance which may be set to produce different amplification contrasts as for gamma control. In another modification, the second diode 43 is provided but the auxiliary valve 53 is omitted. Specifications 448,065 and 543,709 are referred to.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US367324A US2326907A (en) | 1940-11-27 | 1940-11-27 | Television system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB553381A true GB553381A (en) | 1943-05-19 |
Family
ID=23446708
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB15239/41A Expired GB553381A (en) | 1940-11-27 | 1941-11-26 | Improvements in television systems |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US2326907A (en) |
| GB (1) | GB553381A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE954338C (en) * | 1950-11-09 | 1956-12-13 | Philips Nv | Circuit for automatic gain control in a television receiver |
| DE1045448B (en) * | 1953-09-05 | 1958-12-04 | Standard Elektrik Lorenz Ag | Circuit arrangement to avoid the penetration of energy of the actual message content into the synchronous level range |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2426710A (en) * | 1945-01-27 | 1947-09-02 | Farnsworth Television & Radio | Composite television signal generator |
| US2692299A (en) * | 1948-12-11 | 1954-10-19 | Westinghouse Electric Corp | Image contrast intensifier |
| US2724738A (en) * | 1949-07-02 | 1955-11-22 | Pye Ltd | Black and white signal limiter |
| FR2117909B1 (en) * | 1970-12-16 | 1976-12-03 | Fernseh Gmbh |
-
1940
- 1940-11-27 US US367324A patent/US2326907A/en not_active Expired - Lifetime
-
1941
- 1941-11-26 GB GB15239/41A patent/GB553381A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE954338C (en) * | 1950-11-09 | 1956-12-13 | Philips Nv | Circuit for automatic gain control in a television receiver |
| DE1045448B (en) * | 1953-09-05 | 1958-12-04 | Standard Elektrik Lorenz Ag | Circuit arrangement to avoid the penetration of energy of the actual message content into the synchronous level range |
Also Published As
| Publication number | Publication date |
|---|---|
| US2326907A (en) | 1943-08-17 |
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