GB573274A - Keystone correction circuit for television apparatus - Google Patents

Keystone correction circuit for television apparatus

Info

Publication number
GB573274A
GB573274A GB12749/43A GB1274943A GB573274A GB 573274 A GB573274 A GB 573274A GB 12749/43 A GB12749/43 A GB 12749/43A GB 1274943 A GB1274943 A GB 1274943A GB 573274 A GB573274 A GB 573274A
Authority
GB
United Kingdom
Prior art keywords
scanning
fed
choke
waves
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
Application number
GB12749/43A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Farnsworth Television and Radio Corp
Original Assignee
Farnsworth Television and Radio Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Farnsworth Television and Radio Corp filed Critical Farnsworth Television and Radio Corp
Publication of GB573274A publication Critical patent/GB573274A/en
Expired legal-status Critical Current

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
    • H04N3/16—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical by deflecting electron beam in cathode-ray tube, e.g. scanning corrections
    • H04N3/22—Circuits for controlling dimensions, shape or centering of picture on screen
    • H04N3/23—Distortion correction, e.g. for pincushion distortion correction, S-correction
    • H04N3/233—Distortion correction, e.g. for pincushion distortion correction, S-correction using active elements
    • 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
    • H04N3/16—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical by deflecting electron beam in cathode-ray tube, e.g. scanning corrections
    • H04N3/22—Circuits for controlling dimensions, shape or centering of picture on screen
    • H04N3/23—Distortion correction, e.g. for pincushion distortion correction, S-correction
    • H04N3/237—Distortion correction, e.g. for pincushion distortion correction, S-correction using passive elements, e.g. diodes

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Details Of Television Scanning (AREA)
  • Video Image Reproduction Devices For Color Tv Systems (AREA)

Abstract

573,274. Television; electronic scanning. FARNSWORTH TELEVISION & RADIO CORPORATION. Aug. 6, 1943, No. 12749. Convention date, April 30, 1942. [Class 40 (iii)] In a television scanning circuit in which the line-scanning wave is modulated in accordance with the varying amplitude of the field-scanning wave for correcting keystone distortion, the modulator 20 comprises two valves 25, 26 connected in push-pull, the grids of the valves being fed with line-scanning waves of equal amplitude, but of opposite polarity, the anodes being fed in parallel over lead 46 with the fieldscanning waves and the cathodes beingcorinected through a balanced choke 35. The two opposing windings of the choke lie side by side and close together and the mid-point is connected to ground through a resistance 29 and condenser 28, the choke and its connections serving to remove from the modulated linescanning wave the fundamental and higherorder frequencies of the field-scanning wave. The modulated line-scanning wave is fed from the choke 35 through an amplifier 38 to the deflecting coils 42 of the cathode-ray tube 40. The line-deflecting saw-tooth waves of opposite polarity supplied to the modulator 20 over leads 16, 17 are generated by two similar condenser resistance timing circuits 7, 8 ; 12, 13 connected respectively to the anode and cathode of a valve 10, the grid of which is fed with square-topped waves from a generator 2. Specification 573,272 is referred to.
GB12749/43A 1942-04-30 1943-08-06 Keystone correction circuit for television apparatus Expired GB573274A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US441205A US2369824A (en) 1942-04-30 1942-04-30 Keystone correction circuit

Publications (1)

Publication Number Publication Date
GB573274A true GB573274A (en) 1945-11-14

Family

ID=23751957

Family Applications (1)

Application Number Title Priority Date Filing Date
GB12749/43A Expired GB573274A (en) 1942-04-30 1943-08-06 Keystone correction circuit for television apparatus

Country Status (2)

Country Link
US (1) US2369824A (en)
GB (1) GB573274A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL244814A (en) * 1958-10-29

Also Published As

Publication number Publication date
US2369824A (en) 1945-02-20

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