GB514401A - Improvements in or relating to television and like systems - Google Patents
Improvements in or relating to television and like systemsInfo
- Publication number
- GB514401A GB514401A GB1329838A GB1329838A GB514401A GB 514401 A GB514401 A GB 514401A GB 1329838 A GB1329838 A GB 1329838A GB 1329838 A GB1329838 A GB 1329838A GB 514401 A GB514401 A GB 514401A
- Authority
- GB
- United Kingdom
- Prior art keywords
- signal
- valve
- television
- component
- amplifier
- 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
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)
- Television Receiver Circuits (AREA)
- Electron Tubes For Measurement (AREA)
Abstract
514,401. Valve amplifying circuits ; television. BAIRD TELEVISION, Ltd., and NUTTALL, T. C. May 4, 1938, No. 13298. [Classes 40 (iii) and 40 (v)] The contrast range of a television or like signal is modified by varying the gain of an amplifier by controlling the negative feed-back so as to depend on the instantaneous value of the signal and to make the feed-back zero for a finite value of applied signal. The Figure shows a linear amplifier 1 the linearity of which may be increased by resistances 10, 12 and serves as a high impedance signal source. The anode circuit of the amplifier 1 is arranged in parallel with the anode circuit of a valve 4 having a non- linear characteristic and its grid fed from the output of the valve 1 in such a manner as to produce negative feed-back. As shown, the signal is amplified by the cathode follower 7 and the D.C. component is inserted by the diode 9 the amplitude of the D.C. component relative to that of the A.C. component being determined by the ratio of resistances 13, 14. Resistance 16 and condenser 3 remove the saw-tooth error in the D.C. component. Numerical data are given in an example and the valve 4 may have a parabolic or an exponential characteristic and give a reduction in contrast particularly when transmission is from a photographic film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1329838A GB514401A (en) | 1938-05-04 | 1938-05-04 | Improvements in or relating to television and like systems |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1329838A GB514401A (en) | 1938-05-04 | 1938-05-04 | Improvements in or relating to television and like systems |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB514401A true GB514401A (en) | 1939-11-07 |
Family
ID=10020414
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1329838A Expired GB514401A (en) | 1938-05-04 | 1938-05-04 | Improvements in or relating to television and like systems |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB514401A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE955778C (en) * | 1952-07-26 | 1957-01-10 | Int Standard Electric Corp | Circuit arrangement for simultaneous gradation control and increase of the high frame rates |
| DE955777C (en) * | 1953-06-21 | 1957-01-10 | Fernseh Gmbh | Circuit for amplifying video-frequency television signals |
-
1938
- 1938-05-04 GB GB1329838A patent/GB514401A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE955778C (en) * | 1952-07-26 | 1957-01-10 | Int Standard Electric Corp | Circuit arrangement for simultaneous gradation control and increase of the high frame rates |
| DE955777C (en) * | 1953-06-21 | 1957-01-10 | Fernseh Gmbh | Circuit for amplifying video-frequency television signals |
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