GB287844A - Improvements in or relating to photo electric apparatus and circuits therefor - Google Patents
Improvements in or relating to photo electric apparatus and circuits thereforInfo
- Publication number
- GB287844A GB287844A GB4251/28A GB425128A GB287844A GB 287844 A GB287844 A GB 287844A GB 4251/28 A GB4251/28 A GB 4251/28A GB 425128 A GB425128 A GB 425128A GB 287844 A GB287844 A GB 287844A
- Authority
- GB
- United Kingdom
- Prior art keywords
- light
- cell
- photo
- copying
- picture
- 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
- 238000010521 absorption reaction Methods 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/30—Transforming light or analogous information into electric information
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Facsimile Scanning Arrangements (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
287,844. Telefunken Ges. f³r Drahtlose Telegraphie. March 26, 1927, [Convention date]. Copying-telegraphs.-In a copying-telegraph or the like comprising one or more light-sensitive devices, such as a photo-electric cell 5, one or more additional compensating light-sensitive devices 9 are arranged so that the effective output is substantially zero during light shades of a picture or the like 4 and increases with increasing darkness of shade in the picture. The invention facilitates the direct reproduction of a positive by an electro-chemical or photographic receiver. The photo-electric cells are connected in a bridge circuit which is balanced for light shades by adjusting the light falling on the compensating cell by moving a mirror 6 which reflects light from the beam falling on the cell 5, or by an iris diaphragm, or by an absorption wedge. The carrier frequency is produced bv a rapidly rotating perforated disc 7, or by a. source of alternating potential in series with a source of direct potential 10 (Fig. 2. not shown).
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE287844X | 1927-03-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB287844A true GB287844A (en) | 1928-06-28 |
Family
ID=6059390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB4251/28A Expired GB287844A (en) | 1927-03-26 | 1928-02-10 | Improvements in or relating to photo electric apparatus and circuits therefor |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US1770497A (en) |
| FR (1) | FR651051A (en) |
| GB (1) | GB287844A (en) |
| NL (1) | NL23519C (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2721275A (en) * | 1935-02-21 | 1955-10-18 | Albert M Jackson | Method of and means for detecting aircraft |
| US2531951A (en) * | 1944-08-02 | 1950-11-28 | W I Westervelt | Interference reducing method of secret communication |
| US3014135A (en) * | 1957-03-04 | 1961-12-19 | Hewlett Packard Co | Direct current amplifier and modulator therefor |
| US3197643A (en) * | 1960-12-30 | 1965-07-27 | Ibm | Electro-optical plane aligning apparatus |
| FR1555808A (en) * | 1967-12-11 | 1969-01-31 |
-
0
- NL NL23519D patent/NL23519C/xx active
-
1928
- 1928-02-10 GB GB4251/28A patent/GB287844A/en not_active Expired
- 1928-03-20 FR FR651051D patent/FR651051A/en not_active Expired
- 1928-03-31 US US266153A patent/US1770497A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US1770497A (en) | 1930-07-15 |
| NL23519C (en) | |
| FR651051A (en) | 1929-02-14 |
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