GB1211396A - Automatic dark current control system for pickup tubes - Google Patents
Automatic dark current control system for pickup tubesInfo
- Publication number
- GB1211396A GB1211396A GB36362/68A GB3636268A GB1211396A GB 1211396 A GB1211396 A GB 1211396A GB 36362/68 A GB36362/68 A GB 36362/68A GB 3636268 A GB3636268 A GB 3636268A GB 1211396 A GB1211396 A GB 1211396A
- Authority
- GB
- United Kingdom
- Prior art keywords
- target
- dark current
- mask
- circuit
- control system
- 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
- 230000005540 biological transmission Effects 0.000 abstract 1
- 230000002401 inhibitory effect Effects 0.000 abstract 1
- 238000005070 sampling Methods 0.000 abstract 1
Classifications
-
- 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
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/70—Circuitry for compensating brightness variation in the scene
- H04N23/749—Circuitry for compensating brightness variation in the scene by influencing the pick-up tube voltages
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Color Television Image Signal Generators (AREA)
- Processing Of Color Television Signals (AREA)
Abstract
1,211,396. Television. SONY CORP. 30 July, 1968 [1 Aug., 1967], No. 36362/68. Heading H4F. In an automatic dark current control system for a pick-up tube a light transmission inhibiting region is provided on the target of the tube and the video signal level produced when this region is scanned is employed to control the target voltage to hold this level constant. Thus, as shown in Fig. 3, a mask 8 is disposed on the target 5 and the video signal level E B (Fig. 4) occurring in a dark current period T D following the horizontal fly-back period T B and due to the presence of the mask is detected by a circuit 10 (Fig. 2), comprising e.g. a sampling circuit supplied with horizontal synchronizing pulses derived from the deflection circuit 12, and compared with a reference voltage E in a comparator 13 the output of which is applied to a target voltage control circuit 14 which controls the target voltage by feed-back to maintain level E B substantially constant. The invention compensates for dark current changes due to temperature variations and is of particular advantage in maintaining white balance in colour television cameras employing a plurality of pick-up tubes. The mask 8 may be positioned along a horizontal edge of the target instead of, a vertical edge.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4944567 | 1967-08-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1211396A true GB1211396A (en) | 1970-11-04 |
Family
ID=12831310
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB36362/68A Expired GB1211396A (en) | 1967-08-01 | 1968-07-30 | Automatic dark current control system for pickup tubes |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US3558809A (en) |
| DE (1) | DE1762657C3 (en) |
| GB (1) | GB1211396A (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2125165C3 (en) * | 1971-05-21 | 1974-05-22 | Robert Bosch Fernsehanlagen Gmbh, 6100 Darmstadt | Process for the automatic adjustment of the amplifiers in the color channels of color imagers |
| JPS591028B2 (en) * | 1973-02-16 | 1984-01-10 | キヤノン株式会社 | Optical system of color television imaging device |
| JPS5548514B2 (en) * | 1973-12-28 | 1980-12-06 | ||
| JPS51131210A (en) * | 1975-05-10 | 1976-11-15 | Teac Co | Video camera |
| JPS5452418A (en) * | 1977-10-04 | 1979-04-25 | Victor Co Of Japan Ltd | Stabilization system for black level of color television camera |
| JPS592426B2 (en) * | 1978-01-20 | 1984-01-18 | 日本ビクター株式会社 | vertical deflection circuit |
| US4385322A (en) * | 1978-09-01 | 1983-05-24 | View Engineering, Inc. | Pattern recognition apparatus and method |
| DE3115092A1 (en) * | 1980-04-18 | 1982-02-04 | Canon K.K., Tokyo | VIDEO CAMERA |
| US4399466A (en) * | 1981-12-24 | 1983-08-16 | Calspan Corporation | Dark current compensating lens iris control |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3126447A (en) * | 1964-03-24 | figure | ||
| DE1170453B (en) * | 1959-11-25 | 1964-05-21 | Fernseh Gmbh | Circuit arrangement for almost constant holding of the amplified video signal generated by an image recording tube of the vidicon type with changing lighting of the photo layer |
| US3206547A (en) * | 1962-11-19 | 1965-09-14 | Motorola Inc | Automatic control system |
| US3407267A (en) * | 1964-06-15 | 1968-10-22 | Hogan Faximile Corp | Scanner with stabilized black level output |
-
1968
- 1968-07-30 DE DE1762657A patent/DE1762657C3/en not_active Expired
- 1968-07-30 US US748714A patent/US3558809A/en not_active Expired - Lifetime
- 1968-07-30 GB GB36362/68A patent/GB1211396A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE1762657B2 (en) | 1977-01-20 |
| US3558809A (en) | 1971-01-26 |
| DE1762657A1 (en) | 1971-04-29 |
| DE1762657C3 (en) | 1978-08-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PE20 | Patent expired after termination of 20 years |