Abstract:
A yoke adapted for use with a wide deflection angle picture tube used in a television receiver set is disclosed, in which a horizontal yoke is of saddle-shape and a fringe thereof is of non-circular shape so that a raster scanned on the picture tube shows no vertical pincushion distortion.
Abstract:
1490812 Linear accelerators ATOMIC ENERGY OF CANADA Ltd 17 July 1975 [15 Aug 1974] 30026/75 Heading H1D The magnet deflection system of Fig. 3, having four magnets 31, 32, 33, and 34 symmetrically arranged about a plane 35, and producing deflection of a charged particle beam through 180 degrees such that it exits in the reverse direction along its entrance path, e.g. for use in a standing wave linear accelerator, is arranged to be achromatic and isochronous, and to produce an exit beam of substantially the same size as the entrance beam, by suitable choice of the system parameters.
Abstract:
1317434 High speed television camera JOHN HADLAND (PHOTOGRAPHIC INSTRUMENTATION) Ltd 18 May 1970 [16 May 1969] 25174/69 Heading H4F In a high-speed camera, Fig. 1, in which an image of a phenomenon is formed on a photocathode 12 and the resulting electron image is directed on to a screen 15 via an aperture 14 in an earthed anode 13, the image being periodically swept across an aperture 17 in a plate 16 by means of deflector plates 18 to which an oscillating (preferably sinusoidal) waveform is applied and immobilized by deflector plates 19 to which a similar but phase-displaced waveform is applied i.e. successive stationary images at two spaced positions (A and B, Fig. 4) are produced on the screen, and in which deflector plates 20 deflect the image at an angle (preferably 90 degrees) to the plane of deflection caused by the plates 18 and 19 in response to the occurrence of the phenomenon to be recorded, this deflection by plates 20 which produces successive pairs of images on the screen (see Fig. 4) is initiated irrespective of the phase of the waveforms applied to the deflector plates 18 and 19. The waveforms applied to plates 18 and 19 which are phase displaced by more than 180 degrees so that two distinct image residence positions are produced on the screen, are produced by a triggerable oscillatory circuit 21 connected to a feedback amplifier 23 that maintains the oscillations constant once the oscillator has been triggered 22. A further trigger 28 operable by the phenomenon to be recorded is connected to an amplifier and shaper 29 and then to a gating stage 30 which receives an input from circuit 21 so that the "steps" of the output of a staircase generator 31, which is applied to the deflector plates 20, occur concurrently with the positive peaks of the waveform applied to the shutter plates 18. In addition the output of 29 is connected directly to the staircase generator 31 so that the operation of the trigger 28 causes the first "step" in the output of the staircase generator 31 irrespective of the phase of the output of the oscillatory 21. The second and subsequent "steps" being governed by the phase of circuit 21. Trigger 22 is preferably operated shortly before the occurrence of the phenomenon to the recorded. In operation if trigger 28 is not operated subsequent to the operation of trigger 22 the images will continue to be formed at A and B, superimposed over the previous image. In dependence upon when trigger 28 is operated either images may be formed sequentially at all the positions A-H in Fig. 4, or positions C and D will be blank, or positions B and C will be blank.
Abstract:
1,145,343. Electron-beam deflection control. GENERAL ELECTRIC CO. 15 July, 1966 [4 Aug., 1965], No. 31987/66. Heading H4T. In an arrangement for deflecting an electron beam in a desired geometric pattern (e.g. in an electron-beam welding machine), X and Y coordinate voltages representative of the end points of each segment, in the case of straight line patterns, of a particular pattern are selected from a plurality of such voltages, and fed to selected taps on respective X, Y slider potentiometers, the outputs of which, when the latter are rotated, provide the required X and Y beam deflection controls whilst, for circular patterns, the outputs of a sine-cosine potentiometer are utilized. The co-ordinate voltages for certain predetermined patterns, e.g. circle, hexagon, triangle and rectangles having ratios (1: 1, 1: 2, 1:5) of sides are produced by supplying D.C. voltages of -12V and +12V from respective terminals 5a, 5b (see Figs. 2a, 2b, 2c) of a power supply 5 to a voltage divider network 6, the various taps on which supply the X co-ordinate voltages over a cable 200a and the Y coordinate voltages over a cable 100a to certain contacts of twelve decks of a fourteen deck switch 8, the co-ordinate voltages for additional " special " patterns being produced by supplying suitable D.C. voltages to tappings 300-311, and 400-411 in cables 300a, 400a connected to other contacts on the twelve switch decks. Switch 8 is operated to select the co-ordinate voltages appropriate to a desired pattern and the outputs from the various decks are supplied to tappings on X and Y linear resistance potentiometers 9, 10 rotated manually or via a slip clutch driven by motor 16 controlled by speed controller 19 (also Fig. 1, not shown) to produce the actual beam deflection waveforms. The latter are supplied to output terminals 11, 12 via one section 7b of a change-over switch 7 and banks 13 and 14 of switch 8. Section 7b of switch 7 is linked to a section 7a which when operated reverses the polarity of the voltage across the X co-ordinate section of network 6 so that on operation of both sections the pattern is rotated through 90 degrees in a clockwise direction. For the production of circular patterns the output of a sine-cosine potentiometer 14 coupled to the drive shaft of potentiometers 9, 10 and fed via conductors S, V with the voltage across network 6 is supplied to terminals 11, 12, instead of the outputs of the potentiometers, by operation of switch 8 (decks 13 and 14). To increase the effective width of the electron beam a " puddling " (spot-wobble) technique is employed. This is achieved by the circuit of Fig. 2a which provides, at terminals 11a, 12a, two 90 degrees phase-displaced waveforms at the power line frequency (60 c.p.s.) amplitude modulated by a multivibrator 24, the depth of which is controlled by rheostat 25 and the frequency by potentiometer 24b, the circuit being brought into operation by switch 28. The outputs at terminals 11, 12 and 11a, 12a are then supplied to the correspondingly referenced inputs of respective X and Y D.C. amplifiers (Fig. 3, not shown) including negative feedback stabilization, the outputs of which feed the deflection coils for the electron beam. To minimize distoration of the geometric pattern due to non-linearity of the deflection coils, the output circuit of each amplifier includes a photo-resistor influenced by a respective light bulb connected in the output circuit of the other amplifier.
Abstract:
Methods and systems for acquiring transmission electron microscope video data on a rolling-shutter detector at an enhanced frame rate and without temporal distortions are described. Also described are methods to enhance the dynamic range of image and diffraction data acquired using a transmission electron microscope. The disclosed methods and systems may also be applicable to photon detection and imaging systems.
Abstract:
The invention relates to an apparatus for generating a plurality of charged particle beamlets, comprising a charged particle source for generating a diverging charged particle beam, a converging means for refracting said diverging charged particle beam and a lens array comprising a plurality of lenses, wherein said lens array is located between said charged particle source and said converging means. In this way, it is possible to reduce aberrations of the converging means.
Abstract:
A circuit is described for applying RF and AC voltages to the elements or electrodes of an ion trap or ion guide. The circuit includes an RF transformer having a primary winding and a secondary winding. The secondary winding includes at least two filars. A broadband transformer adapted to be connected to a source of AC voltage applies AC voltage across the low-voltage end of two of the filars. Another broadband transformer connected to the filars at the high-voltage end provides a combined RF and AC output for application to selected electrodes. Also described is a circuit employing a multi-filar RF transformer and broadband transformers for applying RF and AC voltages to spaced rods of a linear ion trap. Also described is a circuit employing a multi-filar RF transformer and broadband transformers for applying RF and AC voltages to the electrodes in each section of a linear ion trap of the type having a center section and end sections, and different DC voltages to the electrodes in the end sections.