GB400275A - Improvements in or relating to photophones - Google Patents

Improvements in or relating to photophones

Info

Publication number
GB400275A
GB400275A GB11733/32A GB1173332A GB400275A GB 400275 A GB400275 A GB 400275A GB 11733/32 A GB11733/32 A GB 11733/32A GB 1173332 A GB1173332 A GB 1173332A GB 400275 A GB400275 A GB 400275A
Authority
GB
United Kingdom
Prior art keywords
lamp
light
receiver
sighting
diaphragm
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
GB11733/32A
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.)
Marconis Wireless Telegraph Co Ltd
BAE Systems Electronics Ltd
Original Assignee
Marconis Wireless Telegraph Co Ltd
Marconi Co Ltd
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 Marconis Wireless Telegraph Co Ltd, Marconi Co Ltd filed Critical Marconis Wireless Telegraph Co Ltd
Priority to GB11733/32A priority Critical patent/GB400275A/en
Priority to US667476A priority patent/US2031198A/en
Publication of GB400275A publication Critical patent/GB400275A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B10/00Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/11Arrangements specific to free-space transmission, i.e. transmission through air or vacuum

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Spectrometry And Color Measurement (AREA)

Abstract

400,275. Photophones. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Marconi House, Strand, London, WRIGHT, G. M., Burford, Great Baddow, Chelmsford, and BRETT, G. F., 23, Cross Flatts Avenue, Dewsbury Road, Leeds. April 23, 1932, No. 11733. [Class 40 (v).] A photophone uses approximately monochromatic light. A neon-filled glow-discharge lamp T is used with sodium in the envelope and associated with a heater which keeps the lamp at such a temperature that the light emitted corresponds to the sodium D lines. When the heater is not used the light is ordinary neon red. The light is directed to the receiver by a parabolic mirror adjusted by a sighting-device. The lamp is in the output circuit of a valve 6, to the grid 8 of which the signals are applied. The valve is shunted by a resistance 7. According to a modification, the lamp is connected across the anode battery 4, Fig. 3 (not shown). At the receiver the monochromatic light is separated by a filter, Fig. 4. (not shown), or by a prism P behind a diaphragm D1 and in front of a diaphragm D2 which is adjusted to select the desired colour. The receiver is directed towards the transmitter by a sighting- device.
GB11733/32A 1932-04-23 1932-04-23 Improvements in or relating to photophones Expired GB400275A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB11733/32A GB400275A (en) 1932-04-23 1932-04-23 Improvements in or relating to photophones
US667476A US2031198A (en) 1932-04-23 1933-04-22 Photophone

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB11733/32A GB400275A (en) 1932-04-23 1932-04-23 Improvements in or relating to photophones

Publications (1)

Publication Number Publication Date
GB400275A true GB400275A (en) 1933-10-23

Family

ID=9991672

Family Applications (1)

Application Number Title Priority Date Filing Date
GB11733/32A Expired GB400275A (en) 1932-04-23 1932-04-23 Improvements in or relating to photophones

Country Status (2)

Country Link
US (1) US2031198A (en)
GB (1) GB400275A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2562887A (en) * 1945-01-04 1951-08-07 Westinghouse Electric Corp Vapor lamp and system
US2970310A (en) * 1947-09-23 1961-01-31 Bell Telephone Labor Inc Light pulse generator
FR1485625A (en) * 1966-04-14 1967-06-23 Csf New monochromatic light source of constant intensity

Also Published As

Publication number Publication date
US2031198A (en) 1936-02-18

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