GB617872A - Automatic control system suitable for use in the focusing of television pick-up tubes - Google Patents
Automatic control system suitable for use in the focusing of television pick-up tubesInfo
- Publication number
- GB617872A GB617872A GB10449/45A GB1044945A GB617872A GB 617872 A GB617872 A GB 617872A GB 10449/45 A GB10449/45 A GB 10449/45A GB 1044945 A GB1044945 A GB 1044945A GB 617872 A GB617872 A GB 617872A
- Authority
- GB
- United Kingdom
- Prior art keywords
- motor
- ssa
- camera
- operating
- osw
- 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
- 239000004020 conductor Substances 0.000 abstract 4
- 230000003287 optical effect Effects 0.000 abstract 2
- 230000002441 reversible effect Effects 0.000 abstract 2
- 230000003321 amplification Effects 0.000 abstract 1
- 230000001419 dependent effect Effects 0.000 abstract 1
- 239000011521 glass Substances 0.000 abstract 1
- 238000007689 inspection Methods 0.000 abstract 1
- 230000004048 modification Effects 0.000 abstract 1
- 238000012986 modification Methods 0.000 abstract 1
- 238000003199 nucleic acid amplification method Methods 0.000 abstract 1
- 230000010363 phase shift Effects 0.000 abstract 1
- 238000007493 shaping process 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
- H04N23/60—Control of cameras or camera modules
- H04N23/66—Remote control of cameras or camera parts, e.g. by remote control devices
- H04N23/661—Transmitting camera control signals through networks, e.g. control via the Internet
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
- H04N23/67—Focus control based on electronic image sensor signals
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Closed-Circuit Television Systems (AREA)
- Automatic Focus Adjustment (AREA)
Abstract
617,872. Automatic control systems. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. April 25, 1945, No. 10449. Convention date, April 25, 1944. [Class 38 (iv)] [Also in Group XL (b)] A control system providing automatic focusing of a television camera comprises means for deriving signals representative of a selected portion of a scene to be televised and means for utilizing the derived signals to automatically control the focusing means of the camera by comparison of energies respectively dependent upon the position of the focusing means at two successive time intervals. An image of an object 38 is focused on the screen 11 of an iconoscope type tube 10 and also on a half-silvered glass screen 42 by the optical systems 36, 41 respectively (Fig. 1). Both optical systems are carried by a rack 46 driven by means of a pinion 47 and reversible motor 49. A source SG supplies horizontal and vertical beam deflection energy and synchronizing and blanking signals for the tube 10 and for a cathode-ray tube CR. The source SG also provides controlling signals for two oscillators OSW<SP>1</SP> and OSW<SP>11</SP>, Fig. 2, the former operating at line frequency and the latter of a frequency of 10 c.p.s. (approx.). The outputs of both of these oscillators are fed to phase-shifters PS<SP>1</SP> and PS<SP>11</SP>, having a phase-shift range of about 180 degrees, and thence through rectifying and shaping stages which produce output pulse waveforms 62 and 72 respectively. These pulses are combined in the conductor 47 to provide operating bias for the control element 70 of CR and for the amplifier SSA (Fig. 1) which amplifies the image signal output of PA. The operating biasses of both CR and SSA are such that the pulses 62, 72 must be made to coincide in time, by adjustment of PS<SP>1</SP> and PS<SP>11</SP>, to cause the former (i.e. CR and SSA) to become operative. Thus, any area of the image of 38 on VF may be selected by the beam 78 by this adjustment and in this condition SSA passes only the portion of the image signal which represents this selected area. When this area is correctly focussed, the output of the tube 10 is a maximum and, after amplification by PA and SSA, the H.F. component of this signal is applied to the control grids of V1 and V2 over conductor 90 (Fig. 3). These valves also receive square wave biassing pulses controlled by the oscillator OSW<SP>111</SP>, operating at about 10 c.p.s., so that they operate alternately to amplifying the signal applied over conductor 90. RV1 and RV2 rectify the outputs of V1 and V2 respectively so that the point 110 assumes positive or negative polarity according to which of the valves V1, V2 is operating, this being determined by the relative amplitudes of the signals fed over conductor 90 between successive cycles of OSW<SP>111</SP>, and these changes in polarity are applied over 19 to polarized relay 82 which operates contacts 128, 129 to reverse the direction of current in the motor field coil 122. When the signal output of 10 changes to a lower value, due to 38 going out of focus, the motor 49 operates to counteract this movement and consequently to increase the output of 10. When switched on initially, if the desired area of 38 is completely out of focus, the motor may continue to drive the lens system to still further decrease the desired signal output until either of the projections 143, 144 on the rack 46 operate the limit switches 141, 142 in the relay circuit 147. This relay energizes the stepping magnet 149 which is provided with a pawl-and-ratchet 151, 152 and intermittently drives switch arm 153 of rotary switch 154, alternate contact studs 156 being connected to a source of negative polarity and intermediate studs 159 to a source of positive polarity so that the polarized relay 124 which operates the motor reversal contacts 136, 137 is fed with a voltage of the required polarity. Instead of allowing the rack to be driven to the extremity of its travel, a reversal of the motor may be effected by the manuallyoperated switch 165 which operates in the same manner as the limit switches. The Specification as open to inspection under Sect. 91 describes a modification in which the driving motor and associated control apparatus and the apparatus of Fig. 3 are omitted and the camera is focussed by any usual manual control, the output of amplifier HF being rectified and applied to the cathode-ray tube CR so that the spot produced on the screen thereof is brightest when the selected portion of the object 38 is correctly focussed. Alternatively, a meter either at the camera or at a remote point may be used to indicate when the camera is in focus on the selected area (Fig. 4, Cancelled, not shown). This subject-matter does not appear in the Specification as accepted.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US532579A US2403628A (en) | 1944-04-25 | 1944-04-25 | Television pickup control system |
Publications (1)
Publication Number | Publication Date |
---|---|
GB617872A true GB617872A (en) | 1949-02-14 |
Family
ID=24122348
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB10449/45A Expired GB617872A (en) | 1944-04-25 | 1945-04-25 | Automatic control system suitable for use in the focusing of television pick-up tubes |
Country Status (2)
Country | Link |
---|---|
US (1) | US2403628A (en) |
GB (1) | GB617872A (en) |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2532063A (en) * | 1946-09-07 | 1950-11-28 | Rca Corp | Position indicating system |
FR957367A (en) * | 1946-12-17 | 1950-02-18 | ||
GB632726A (en) * | 1947-07-04 | 1949-12-05 | Nathaniel Quentin Lawrence | View finder for television cameras |
US2572729A (en) * | 1948-03-16 | 1951-10-23 | Pye Ltd | Television camera focusing mechanism |
US2725423A (en) * | 1951-02-28 | 1955-11-29 | Rca Corp | Apparatus for positioning television images in multiple camera systems |
US2972660A (en) * | 1952-09-03 | 1961-02-21 | Moore And Hall | Frequency adjustment system |
FR1098661A (en) * | 1952-09-22 | 1955-08-17 | Int Standard Electric Corp | Optical or electro-optical image autofocus system |
US2838600A (en) * | 1952-09-22 | 1958-06-10 | Itt | Focusing adjusting system |
US2999436A (en) * | 1954-09-04 | 1961-09-12 | Voigtlaender Ag | Process and device for automatically adjusting optical instruments |
US2964590A (en) * | 1958-11-25 | 1960-12-13 | Gen Precision Inc | Automatic focusing system |
US3061673A (en) * | 1959-02-05 | 1962-10-30 | Thompson Ramo Wooldridge Inc | Servo system for light level control |
US3450833A (en) * | 1966-01-14 | 1969-06-17 | Itek Corp | Automatic focusing system for a flying-spot scanner |
US3621136A (en) * | 1969-09-10 | 1971-11-16 | Us Navy | Automatic optical-focusing system for tv cameras |
NL8103090A (en) * | 1981-06-26 | 1983-01-17 | Philips Nv | TELEVISION CAMERA EQUIPPED WITH A FOCUSING DEVICE. |
-
1944
- 1944-04-25 US US532579A patent/US2403628A/en not_active Expired - Lifetime
-
1945
- 1945-04-25 GB GB10449/45A patent/GB617872A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
US2403628A (en) | 1946-07-09 |
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