GB399469A - Improvements in or relating to television systems - Google Patents
Improvements in or relating to television systemsInfo
- Publication number
- GB399469A GB399469A GB592932A GB592932A GB399469A GB 399469 A GB399469 A GB 399469A GB 592932 A GB592932 A GB 592932A GB 592932 A GB592932 A GB 592932A GB 399469 A GB399469 A GB 399469A
- Authority
- GB
- United Kingdom
- Prior art keywords
- valve
- condenser
- current
- voltage
- line
- 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
- H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
- H04N3/10—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical
- H04N3/30—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical otherwise than with constant velocity or otherwise than in pattern formed by unidirectional, straight, substantially horizontal or vertical lines
- H04N3/32—Velocity varied in dependence upon picture information
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K4/00—Generating pulses having essentially a finite slope or stepped portions
- H03K4/06—Generating pulses having essentially a finite slope or stepped portions having triangular shape
- H03K4/08—Generating pulses having essentially a finite slope or stepped portions having triangular shape having sawtooth shape
- H03K4/86—Generating pulses having essentially a finite slope or stepped portions having triangular shape having sawtooth shape using as active elements gas-filled tubes or spark-gaps
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Television Receiver Circuits (AREA)
- Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
- Transforming Electric Information Into Light Information (AREA)
- Transforming Light Signals Into Electric Signals (AREA)
- Details Of Television Scanning (AREA)
Abstract
399,469. Converting. BULLIMORE, W. R. and BEDFORD, L. H., Cossor Works, Highbury Grove, London. Feb. 27, 1932, No. 5929. [Class 38 (ii).] In a television system in which a scanning cathode ray moves over a picture at a rate dependent upon the occurrence of light and shade in the picture and is controlled in its movement by a varying potential produced by alternately charging and discharging a condenser, the charging current for the condenser is derived from a thermionic valve, and the discharge of the condenser is also effected through a thermionic valve. The cathode ray oscillograph CRO produces a scanning beam which passes through a film to a photoelectric cell the output from which is fed to an amplifier PCA and to the grid of a screen-grid valve V1 with its screen maintained at a potential such that the plate current charging the condenser C1 and the voltage impressed on the oscillograph plate Py1 are proportional to the output from the photoelectric cell. The condenser C1 is arranged to discharge under control of a valve V3 which may be biased to pass current when a predetermined voltage is reached. Alternatively the valve V3, which may be a power pentode valve, is normally biased to be inoperative but is operated to pass current discharging the condenser C1 by control impulse of the line frequency and produced by a timing circuit N2, R2, R4, C7. The movement of the scanning cathode beam along a line may take place in its own time or a given maximum time mav be allowed for each line. In the latter case the beam is locked just off the edge of the film by the incorporation of a locking valve V2, to the anode of which is applied a predetermined voltage such that when the plate voltage of the valve V1 falls below that of the valve V2, current passes in the valve V2 'and the charging of the condenser C1 ceases. 'At each discharge of the condenser C1, the grid of the valve V5 is biased so that current incrementalty charges the condenser C5 at the end of each line for the line-by-line movement of the scanning beam. At the end of each picture, a pulse is applied from a neon tube timing circuit N1, R1, R3, C6 to the valve V2 to neutralize its locking action, and a larger discharge pulse from the condenser C1 is fed through a small condenser C4 to the grid of a valve V6 which now passes current effecting the discharge of the condenser C5, by which the beam is returned to the first line of the picture. The variations of the voltage applied to the Py1 plate, Fig. 2, are transmitted over a wireless or similar channel and at the receiving station, Fig. 7, are applied to the corresponding plate Py1 of a cathode ray oscillograph. At the end of each line the grid of the valve V5 is biased so that it passes a charging current to the condenser C5, and the large impulse at the end of a picture causes the valve V6 to become operative, effecting the discharge of the condenser C5 and control of the Px plate to return the scanning beam, as at the transmitting station. When the film is moved continuously and is scanned in lines parallel to its direction of motion, the scanning beam is given a displacement in the direction of motion of the film by applying to the normally idle and grounded plate Py2 a voltage at each change of line, and by reducing this voltage to its normal value at the end of each picture. This voltage may be obtained from the voltage supply to the condenser- C5 by throwing the switch K1 to the position shown in dotted lines. The system may be modified to effect scanning in each direction of movement of the cathode beam by incorporating an arrangement as shown in Fig. 8. The grids of the valves V1, V1<1> are controlled by the photo-cell amplifier PCA in antiphase and the screens of the valves are similarly controlled by a multi-vibrator so that only one valve is operative at any time. A screen-grid valve V8 is arranged to pass a constant current for the voltage range of the condenser C1 and in the absence of signals the condenser C1 is alternately charged and discharged by equal currents. When, at any time, two voltages of opposite signs are applied to the valves V1, V1<1> and, for example, a positive voltage to V1, there will be an increment in the V1 current if the V1 valve is operative, or in the current of the valve V1<1> if operating, thus reducing the charging or discharging current, as the case may be, of the condenser C1 and the speed of the scanning spot. The cathode ray tube may be of the form described in Specification 396,422, [Group XL].
Priority Applications (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB592932A GB399469A (en) | 1932-02-27 | 1932-02-27 | Improvements in or relating to television systems |
GB3743/33A GB413401A (en) | 1932-02-27 | 1933-02-07 | Improvements in or relating to television systems |
AT142478D AT142478B (en) | 1932-02-27 | 1933-02-25 | Remote image transmission. |
BE394625D BE394625A (en) | 1932-02-27 | 1933-02-25 | |
FR752450D FR752450A (en) | 1932-02-27 | 1933-02-27 | TV system |
FR44556D FR44556E (en) | 1932-02-27 | 1934-01-11 | TV system |
DEC48725D DE640742C (en) | 1932-02-27 | 1934-01-12 | Playback method for television pictures transmitted by means of speed modulation |
AT144599D AT144599B (en) | 1932-02-27 | 1934-01-19 | Television system. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB592932A GB399469A (en) | 1932-02-27 | 1932-02-27 | Improvements in or relating to television systems |
GB3743/33A GB413401A (en) | 1932-02-27 | 1933-02-07 | Improvements in or relating to television systems |
Publications (1)
Publication Number | Publication Date |
---|---|
GB399469A true GB399469A (en) | 1933-09-27 |
Family
ID=34066581
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB592932A Expired GB399469A (en) | 1932-02-27 | 1932-02-27 | Improvements in or relating to television systems |
GB3743/33A Expired GB413401A (en) | 1932-02-27 | 1933-02-07 | Improvements in or relating to television systems |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3743/33A Expired GB413401A (en) | 1932-02-27 | 1933-02-07 | Improvements in or relating to television systems |
Country Status (5)
Country | Link |
---|---|
AT (2) | AT142478B (en) |
BE (1) | BE394625A (en) |
DE (1) | DE640742C (en) |
FR (2) | FR752450A (en) |
GB (2) | GB399469A (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2678964A (en) * | 1950-08-14 | 1954-05-18 | Hazeltine Research Inc | Modifying the transient response of image-reproducers |
US2851522A (en) * | 1951-12-13 | 1958-09-09 | Columbia Broadcasting Syst Inc | Television |
-
1932
- 1932-02-27 GB GB592932A patent/GB399469A/en not_active Expired
-
1933
- 1933-02-07 GB GB3743/33A patent/GB413401A/en not_active Expired
- 1933-02-25 AT AT142478D patent/AT142478B/en active
- 1933-02-25 BE BE394625D patent/BE394625A/xx unknown
- 1933-02-27 FR FR752450D patent/FR752450A/en not_active Expired
-
1934
- 1934-01-11 FR FR44556D patent/FR44556E/en not_active Expired
- 1934-01-12 DE DEC48725D patent/DE640742C/en not_active Expired
- 1934-01-19 AT AT144599D patent/AT144599B/en active
Also Published As
Publication number | Publication date |
---|---|
GB413401A (en) | 1934-07-19 |
AT142478B (en) | 1935-07-25 |
FR752450A (en) | 1933-09-21 |
FR44556E (en) | 1935-03-04 |
DE640742C (en) | 1937-01-13 |
BE394625A (en) | 1933-03-31 |
AT144599B (en) | 1936-02-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
GB602053A (en) | Improvements relating to colour television reception | |
US2303924A (en) | Television transmitting or receiving system | |
GB376498A (en) | Improvements in or relating to television receiving systems and cathode ray devices suitable for use therein | |
GB555565A (en) | Improvements in and relating to colour television | |
US2285043A (en) | Television receiver | |
US2398641A (en) | Self-synchronizing television system | |
US2134851A (en) | Television and the like systems | |
US2180364A (en) | Cathode ray sweep circuits | |
GB399469A (en) | Improvements in or relating to television systems | |
US2951965A (en) | Cathode ray image display systems | |
US2274686A (en) | Electro-optical system | |
US2305902A (en) | Television transmission | |
US2363822A (en) | Saw-tooth deflection | |
US2096985A (en) | Television | |
US2307249A (en) | Television device | |
US2611820A (en) | Pickup tube beam-interrupting circuit | |
US2102139A (en) | Television system | |
US2210995A (en) | Television and like system | |
US2465667A (en) | Method of and means for controlling the beam current in television camera tubes | |
US2700066A (en) | Television transmitter for use with low illumination | |
GB818669A (en) | Presentation of coloured television pictures | |
US2890278A (en) | Circuit-arrangement for use in television transmitting devices for scanning films | |
US2252746A (en) | Television device | |
GB394883A (en) | Improvements in or relating to television telecinematograph and like systems | |
US2463038A (en) | Direct current insertion circuit |