US2297500A - Television device - Google Patents
Television device Download PDFInfo
- Publication number
- US2297500A US2297500A US355565A US35556540A US2297500A US 2297500 A US2297500 A US 2297500A US 355565 A US355565 A US 355565A US 35556540 A US35556540 A US 35556540A US 2297500 A US2297500 A US 2297500A
- Authority
- US
- United States
- Prior art keywords
- picture
- disturbing signal
- tube
- modulation
- television device
- 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 - Lifetime
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Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/40—Circuit details for pick-up tubes
Definitions
- the second method consists in producing a predetermined voltage for each range of the picture by means of an auxiliary voltage source, such as a cathode ray tube of the kind having a multi-anode for secondary emission. Also in this case the curve of this voltage is simulated to that of the disturbing signal, whereby the disturbing signal may likewise be compensated by subtraction.
- an auxiliary voltage source such as a cathode ray tube of the kind having a multi-anode for secondary emission.
- the curve of this voltage is simulated to that of the disturbing signal, whereby the disturbing signal may likewise be compensated by subtraction.
- one or more cathode ray tubes serving as scanning devices, a diaphragm for each such tube and a photo-electric cell are used for producing the compensation voltage.
- Figs. 1a, 1b is a graph already referred to in explaining the aforesaid prior methods and the main feature of the invention
- Fig. 2 is a diagram showing one embodiment of the invention
- Fig. 3a is a diagrammatic detail view illustrating the construction of diaphragms forming part of the arrangement represented in Fig. 2
- Fig. 3b is a graph which in conjunction with Fig. 31: serves to explain the function of such diaphragms.
- the arrangement illustrated in Fig. 2 comprises two cathode ray tubes R1, R2, arranged to act as dissectors, and a photo-electric cell P.
- the two cathode rays are deflected in only one direcphragms each form a slot of varying width, as
- Fig. 3a The diameter of the spot on the screens of R1, R2 is larger than the maximum width of the slot, as is illustrated by the circle in Fig. 3a.
- the hatched part of this circle indicates the quantity of light passing tion proportionately and synchronously with the through the diaphragm. It will be seen that at each instant of time another quantity of light will pass therethrough, namely, a quantity determined by the distances a and b, the angles 81 and a. and the diameter of the spot of light.
- the curve in Fig. 3b represents the variation the voltage of the photo-electric cell P undergoes, and it will be seen that this curve is rounded owing to the large diameter of the spot of light.
- the quantities of light which pass through the diaphragms B1, B2 are summed up in the cell P. With the values a, b, 61, 62 properly adjusted the voltage at the cell P hence is a simulation of the disturbing signal.
- Such subtraction may be efiected by means of a multi-grid tube, for instance, arranged in the customary modulation amplifier.
- the diaphragms B1, B2 may be adjustable or exchangeable.
- a television transmitter including a cathode ray transmitter tube and means for causin said cathode ray to periodically scan a picture screen and wherein a disturbing signal is introduced during said scanning which signal unevenly shades the picture
- means to compensate for said disturbing signal including a compensating cathode-ray tube having means to trace on its fluorescent screen a line in synchronism with the successive line scannings of the transmitter tube, a photoelectric cell positioned to be excited by the traced line on said compensating tube, and a slotted diaphragm between the screen of said compensating tube and said photoelectric cell for controlling the production of a compensating electrical wave by said cell having a waveform corresponding to said disturbing signal.
- a television transmitter including a cathode ray transmitter tube and means for causing said cathode ray to scan a picture screen in lines corresponding to the vertical and horizontal components of the picture and wherein a disturbing signal is introduced therein by said scannin which signal unevenly shades the picture
- means to compensate for said disturbing signal comprising a pair of cathode-ray tubes each having means to trace on its fluorescent screen a line, one cathode-ray tube tracing a line in time synchronism 10 with the "line scanning in the transmitter tube ARMIN RAPPOLD.
Description
Sept. 29, 1942. A. RAPPOLD 2,297,500
TELEVISION DEVICE Filed Sept. 6, 1940 Patented Sept. 29, 1942 2,297,500 TELEVISION DEVICE Armin Rappold, Berlin, Germany; vested in the Alien Property Custodian Application September 6, 1940, Serial No. 355,565 In Germany October 26, 1939 2 Claims. (Cl. 1787.2)
When scanning a picture projected on the mosaic screen of a picture 'tube then on the receiving side of the television system a modulation is perceived in addition to the modulation which arrives from the picture under scansion. Such additional wrong modulation, spoken of as disturbing signal, is independent of the proper modulation and is uniformly distributed across the picture. During a line or picture period the disturbing signal approximately varies as represented by the curves shown in Figs. la and 11).
Two prior methods, fundamentally ditlerent from each other, aim to compensate the disturbing signal. One of them consists in electrically simulating the curves, illustrated in Figs. 1a and 1b, of the lineor picture-frequency, namely, by
superimposing on a saw-tooth of lineor picture- 1 frequency, respectively, a sine of the same frequency and a sine of double the frequency. All the values here concerned must be adjustable as regards amplitude and phase. .The modulation by which the disturbing signal is simulated in this Way is subtracted from the mixture arriving from the scanning device. As a result, with correct adjustment of all the twelve variables the disturbing signal will be compensated.
The second method consists in producing a predetermined voltage for each range of the picture by means of an auxiliary voltage source, such as a cathode ray tube of the kind having a multi-anode for secondary emission. Also in this case the curve of this voltage is simulated to that of the disturbing signal, whereby the disturbing signal may likewise be compensated by subtraction.
According to the present invention one or more cathode ray tubes serving as scanning devices, a diaphragm for each such tube and a photo-electric cell are used for producing the compensation voltage.
In the drawing, Figs. 1a, 1b is a graph already referred to in explaining the aforesaid prior methods and the main feature of the invention, Fig. 2 is a diagram showing one embodiment of the invention, Fig. 3a is a diagrammatic detail view illustrating the construction of diaphragms forming part of the arrangement represented in Fig. 2, while Fig. 3b is a graph which in conjunction with Fig. 31: serves to explain the function of such diaphragms.
The arrangement illustrated in Fig. 2 comprises two cathode ray tubes R1, R2, arranged to act as dissectors, and a photo-electric cell P. The two cathode rays are deflected in only one direcphragms each form a slot of varying width, as
will be understood from Fig. 3a. The diameter of the spot on the screens of R1, R2 is larger than the maximum width of the slot, as is illustrated by the circle in Fig. 3a. The hatched part of this circle indicates the quantity of light passing tion proportionately and synchronously with the through the diaphragm. It will be seen that at each instant of time another quantity of light will pass therethrough, namely, a quantity determined by the distances a and b, the angles 81 and a. and the diameter of the spot of light. The curve in Fig. 3b represents the variation the voltage of the photo-electric cell P undergoes, and it will be seen that this curve is rounded owing to the large diameter of the spot of light. The quantities of light which pass through the diaphragms B1, B2 are summed up in the cell P. With the values a, b, 61, 62 properly adjusted the voltage at the cell P hence is a simulation of the disturbing signal.
By subtracting this simulation from the modulation arriving from the picture scanning device and which contains the disturbing signal a modulation free from the disturbing signal is obtained. Such subtraction may be efiected by means of a multi-grid tube, for instance, arranged in the customary modulation amplifier.
In order to provide for the best compensation in each case the diaphragms B1, B2 may be adjustable or exchangeable.
What is claimed is: r
1. In a television transmitter including a cathode ray transmitter tube and means for causin said cathode ray to periodically scan a picture screen and wherein a disturbing signal is introduced during said scanning which signal unevenly shades the picture, means to compensate for said disturbing signal including a compensating cathode-ray tube having means to trace on its fluorescent screen a line in synchronism with the successive line scannings of the transmitter tube, a photoelectric cell positioned to be excited by the traced line on said compensating tube, and a slotted diaphragm between the screen of said compensating tube and said photoelectric cell for controlling the production of a compensating electrical wave by said cell having a waveform corresponding to said disturbing signal.
2. In a television transmitter including a cathode ray transmitter tube and means for causing said cathode ray to scan a picture screen in lines corresponding to the vertical and horizontal components of the picture and wherein a disturbing signal is introduced therein by said scannin which signal unevenly shades the picture, means to compensate for said disturbing signal comprising a pair of cathode-ray tubes each having means to trace on its fluorescent screen a line, one cathode-ray tube tracing a line in time synchronism 10 with the "line scanning in the transmitter tube ARMIN RAPPOLD.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE213824X | 1939-10-26 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2297500A true US2297500A (en) | 1942-09-29 |
Family
ID=5815343
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US355565A Expired - Lifetime US2297500A (en) | 1939-10-26 | 1940-09-06 | Television device |
Country Status (4)
Country | Link |
---|---|
US (1) | US2297500A (en) |
BE (1) | BE439216A (en) |
CH (1) | CH213824A (en) |
FR (1) | FR868494A (en) |
-
0
- BE BE439216D patent/BE439216A/xx unknown
-
1940
- 1940-08-22 CH CH213824D patent/CH213824A/en unknown
- 1940-09-06 US US355565A patent/US2297500A/en not_active Expired - Lifetime
- 1940-12-28 FR FR868494D patent/FR868494A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
CH213824A (en) | 1941-03-15 |
FR868494A (en) | 1941-12-31 |
BE439216A (en) |
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