公开(公告)号：DE1016301B

公开(公告)日：1957-09-26

申请号：DEC0006037

申请日：1952-06-28

Applicant: CHROMATIC TELEVISION LAB INC

Inventor： LAWRENCE ERNEST ORLANDO

IPC: H01J21/08 ,  H04N9/24

Abstract: 718,652. Colour television. CHROMATIC TELEVISION LABORATORIES, Inc. June 24, 1952 [June 29, 1951], No. 15833/52. [Also in Group XXXV] In a colour television receiver wherein a scanning cathode-ray beam is arranged to impinge a phosphor target so as successively to develop light in the component colours, a first signal is generated indicative of the rate of repetition of a single selected component colour and compared in phase with a second signal indication of an optimum rate of colour repetition in the selected colour to develop a control signal representation of any difference therebetween, the control signal being applied substantially to eliminate the difference. In one arrangement the control signal is applied to modify the beam scanning velocity. In other arrangements the control signal is applied to modify both the beam scanning velocity and the rate at which the colour signals are applied to modulate the beam. In a first detailed embodiment, Fig. 6, the target of cathoderay tube 11 comprises phosphor strips in the sequence red, green, blue, green &c. which are scanned in a raster with the line direction transverse the strips. Located behind each blue strip is an electrode 33 which intercepts a small portion of the scanning beam and provides a pulse signal on a common connection 36. As the beam scans the target, a pulse series appears on connection 36 indicating the actual rate of scanning. Incoming red, blue and green colour signals appear in separate channels 43, 44, and 45 and are applied to the cathode-ray tube grid 18 through gate stages 75, 75', 75" which are opened in the sequence of scanning the colour phosphors by an oscillator 80 operating at a frequency determined by the optimum rate at which the colours are to be reproduced. Diodes 93 and 93' comprise a phase discriminator circuit to one input of which is applied the oscillator output and to the other input of which is applied the output of an amplifier 98 receiving the pulse series from connection 36. Any difference in phase between the two inputs results in a change of potential at point 100, the potential controlling a reactance tube stage 107 connected across the tuned circuit 85, 86 of the oscillator. Any difference between the actual and optimum rates of colour reproduction therefrom resu'ts in a change in the rate in which the colour signals are gated through to the cathoderay. tube in order to eliminate the difference and a velocity correction is also applied to the line scanning circuit (not shown), a potential to effect this correction being derived from across resistor 90 in the anode circuit of the oscillator. In another detailed embodiment, Fig. 7 (not shown), the oscillator tuned circuit is formed with a saturable reactor and the output of the phase discriminator is applied to control the frequency by means of an additional winding on this reactor. In a third embodiment, Fig. 5 (not shown), the reactance stage controls the line scanning circuit directly. In a fourth embodiment, Fig. 4 (not shown), the output of the phase discriminator circuit controls only the line scanning circuit. As an alternative to using a cathode-ray tube having internal electrodes to detect the passage of the beam over the blue phosphor strips, an external photo-electric cell may be employed in conjunction with an appropriately coloured filter, Fig. 8 (not shown). The electrodes 33 may be more widely spaced than shown in Fig. 6. In Fig. 6 the sequence of colour reproductoin is such that green repeats at twice the rate of either of the other colours and in order to gate the colour signals through in the same sequence it is necessary to open gate 75 11 attwice the rate of the others. This is effected by applying the output of oscil'ator circuit 80 to gate 75 and 75' directly and to gate 75" through a frequency doubling stage 125. To avoid colour contamination when the scanning beam momentarily impinges two phosphors whilst traversing from one to the other, the beam may be keyed at a high frequqency so as to be effective only when the beam impinges the centre of each strip. By this means, it is also possible to maintain a low intensity beam in the absence of signals in order to preserve a pulse output signal in electrodes 33 or the photo-tube in the arrangement of Fig. 8.

公开(公告)号：DE919353C

公开(公告)日：1954-10-21

申请号：DEC0004105

申请日：1951-04-25

Applicant: CHROMATIC TELEVISION LAB INC

Inventor： LAWRENCE ERNEST ORLANDO

IPC: H04N9/26

Abstract: 712,237. Colour televsion tubes. CHROMATIC TELEVISION LABORATORIES, Inc. March 30, 1951 [April 25, 1950], No. 7395/51. Class 39(1) A colour television receiver has a target 25, Fig. 4, formed with a plurality of recesses 27, each recess having a phosphor 35 emitting one colour at the bottom thereof and further phosphor coatings 35 1 , 35 11 emitting other colours deposited successively on the sides thereof, the distance between the centres of adjacent recesses is as small as or smaller than the area of a picture point, and deflecting electrodes 37 additional to the scanning means are provided adjacent to the target for colour switching. The electrodes 37 are narrow strips and are preferably alternately positive and negative. The beam will normally impinge on the green phosphor at the bottom of each recess but by applying a moderate potential difference between pairs of adjacent electrodes 37 the beam contacts the red phosphor and with a higher potential difference contacts the blue phosphor. Electrodes 37 are energized by an oscillator which may or may not provide an additional D.C. bias to modify the rate and sequence of the scan. In modified forms the recesses may be of triangular form and a separate apertured mask disposed in front of the screen, Fig. 5 (not shown), or the mask may be formed integrally with such a screen, Fig. 6 (not shown). The strip deflecting electrodes may be fused at one end to the screen and be formed with mask portions at the other end, Fig. 7 (not shown). One or more positively biased focusing electrodes may be disposed between each pair of deflecting electrodes, the collecting electrodes having a relatively negative and varying potential, Figs. 8, 9 (not shown). in which case the mask may be dispensed with. The strip deflecting electrodes, and focusing electrodes if provided are carried by glass supports 38, Fig. 3, and the structure is strengthened by mica combs 40. Members 44 serve as supports and leads. The tube has one or more focusing and accelerating electrodes and horizontal and vertical scanning coils and the scanning lines may be horizontal, vertical or diagonal. The colour controlling potentials applied to the strip deflecting electrodes may be in field, line or dot sequence. For line or field sequences square wave oscillators, preferably with a D.C. bias, are used. The screen may or may not form the tube end wall. The mask may be formed with Lenard windows of thin foil instead of aoertures, and the screen recesses, permeable mask portions and mica combs are given different inclinations so as to all face the centre of deflection. Instead of a single piece of glass with roundbottomed recesses as in Fig. 1, the screen may be made of alternate wide and narrow strips as indicated by the dotted lines 33 in which case the bottoms may be rounded or flat. A filter may be disposed between the red phosphor and the glass screen as a ruby' coating 46 to correct the colour which by itself is unsatisfactory. The screen may have a reflecting coating of aluminium between the phosphors and the gun e.g. it may be applied to screen faces 31, Fig. 4. Total internal reflection in the screen may also be used to increase the light output.

公开(公告)号：DE1101497B

公开(公告)日：1961-03-09

申请号：DEC0014977

申请日：1957-06-11

Applicant: CHROMATIC TELEVISION LAB INC

Inventor： LAWRENCE ERNEST ORLANDO

IPC: H04N9/26

Abstract: 866,569. Colour television. CHROMATIC TELEVISION LABORATORIES Inc. May 14, 1957 [June 11, 1956], No. 15221/57. Class 40(3) Relates to the reproduction of N.T.S.C. colour signals by means of a single gun cathoderay tube of the type having a line phosphor screen and incorporating post-deflection switching grids for directing the beam on to the respective phosphors. In accordance with the invention the video signal comprising both the luminance component and chrominance subcarrier is applied directly to modulate the tube beam (certain amplitude modifications of the components being effected first, see below) whilst the switching grids are controlled in predetermined phase at subcarrier frequency to cause the beam to execute a cyclic scan of a group of three phosphors, a characteristic feature of the invention being the blanking of the beam during the portion of the cycle so that one of the phosphors is not traversed twice. This feature is illustrated in Fig. 8 which also shows the phase relationship of the cyclic scan with respect to the synchronizing burst and subcarrier. The line scan is assumed to be in the direction of the phosphors and centred on the blue phosphor. Blanking occupies the phase position 162-198 degrees when the beam makes the second reverse traverse of the blue phosphor. In one embodiment the amplitude modification of the video components comprises boosting the chrominance subcarrier to a level 1À37 times that at which it is received. The Specification includes a detailed discussion, Figs. 10a-10g, of the accuracy of colour reproduction obtained. In a second embodiment, a further modification is effected in that the amplitude of the B-Y component of the subcarrier is accentuated relative to the R-Y component. This leads to more accurate colour reproduction which is discussed with reference to Figs. 11a-11f (not shown). It is stated that certain colour imperfections may be corrected by adjustment of the phase of the cyclic scan imparted by the switching grids. Reference is made to scanning the phosphors in directions other than along their length. The Specification includes detailed circuits for carrying out the invention, the techniques involved being, in general, conventional. The circuit for producing the blanking signal, Fig. 5 (not shown), comprises means for passing a signal from the local subcarrier oscillator through an adjustable tapped delay line, so as to permit the production of a wave of any desired phase, followed by a clipping stage for producing an output in response to the positive peak of the wave. The circuit for boosting the chrominance subcarrier, Figs. 2 and 3 (not shown), comprises a video amplifier incorporating a double tuned circuit resonant at the subcarrier frequency and provided with adjustable damping resistors. The circuit for accentuating the B-Y component of the subcarrier relative to the R-Y component may comprise a so-called elliptical amplifier.

公开(公告)号：DE1080595B

公开(公告)日：1960-04-28

申请号：DEC0010457

申请日：1954-12-21

Applicant: CHROMATIC TELEVISION LAB INC

Inventor： LAWRENCE ERNEST ORLANDO

IPC: H01J29/32 ,  H01J29/80 ,  H01J31/20 ,  H04N9/16

Abstract: 773,339. Colour television tubes. CHROMATIC TELEVISION LABORATORIES, Inc. Dec. 22, 1954 [Dec. 22, 1953], No. 37000/54. Class 39(1). Correction of the pin cushion and barrel distortion which gives colour dilution in a colour television tube is obtained by varying the spacing of either the phosphor groups or the deflection grid wires so that the ratio of the group width to the grid aperture width is greater at the centre of the target than at the edges thereof. The mathematical relationships enabling the ratios to be calculated are given in the Specification. In Fig. 7, the spacing of the grid wires 47, 47 is uniform, but the separation of the groups of phosphor strips 45g, 45r, 45b increases outwardly along the central horizontal line whilst remaining constant at the top and bottom edges. In Fig. 8 (not shown) the group separation is constant, but the grid spacing is less along the centre line, the spacing being achieved by accurate notching of the supports and by deforming the damping rods so that they hold the grid wires at the desired separation in the centre portion. The corrected widths of the phosphor groups may be obtained by laying the pattern out on a large scale and reducing photographically to proper size for the production of silk screen stencils or other printing devices therefrom. A second order of correction may be introduced by making a gelatin print of the screen pattern, mounting in a frame with sides bowed outwardly and stretching the frame and gelatin, the stretched frame being rephotographed. Similar corrections are imposed on screens of crossed colour strips and their accompanying crossed colour control wires, Fig. 2 (not shown). Specifications 721,523, 722,282. 757,071 and 757,786 are referred to.

公开(公告)号：DE914386C

公开(公告)日：1954-07-01

申请号：DEC0003949

申请日：1951-03-20

Applicant: CHROMATIC TELEVISION LAB INC

Inventor： LAWRENCE ERNEST ORLANDO

IPC: H04N9/26

Abstract: 721,199. Colour television tubes. CHROMATIC TELEVISION LABORATORIES, Inc. Feb 15, 1951 [March 20, 1950], No. 3645/51. Class 39 (1) In a colour television receiver in which the phosphors are excited in definite sequence by the selective impingement thereon of the beam, one of the phosphors is a translucent layer on the picture area and at least one other phosphor coating is deposited on or supported by a plurality of conducting strips mounted close to and approximately edge on to the translucent layer, the strips being so connected that when they are all at the same potential equal to the layer potential the beam passes between the strips and strikes the layer, while when one strip is made more positive than an adjacent strip the beam passing between them strikes the more positive strip to excite the phosphor coating deposited on or supported thereby. Preferably the translucen layer 23, Fig. 11, is the green phosphor, and may be on the tube end wall or on a separate glass sheet within the envelope and the strips 27' 29', 27', 29' carry alternately red and blue phos phors. The strips are connected in two alternate sets. Other primary colours may be used or in a two-colour system the strips carry phosphors of only one primary colour. The strips may be supported at intervals along their length by glass fibre cords 37, Fig. 4, and the ends of the strips may be held in slots in insulating supports 39 Fig. 3, members 31, 33 acting as leads and sup ports for the structure. In alternative constructions the strips may be notched, Fig. 5 (not shown), and spaced apart by correspondingly notched insula tors. Glass fibre cords pass through the notches and secure the assembly; the notched insulators are slightly wedge-shaped so the beam enters parallel to all the strips. In another form, Fig. 6 (not shown), the strips have corrugations secured to adjacent strips by insulating beads fused thereto. In another form, Fig. 7, glass beads 53 space the strips apart and glass threads 51 hold the assembly together. The beads at the front and rear of the strips are of slightly differen diameter to give the correct tilt to the strips In another form, Fig. 8 (not shown), the strips are wound into spiral form and it is stated that concentric circular or elliptical forms may also be used. In another form, Fig. 9 (not shown) the strips are wedge-shaped, and in a modification, Fig. 10, the strips 27", 29" are wedge shaped and glass beads carrying the red and blue phosphors are fused to their apices. In all forms the strip spacing is not greater than and preferably one-half or one-third of a picture element size and their width about 10 times their spacing. The scanning lines may be parallel, perpendicular or diagonal with respect to the strips. The devices may use field, line or dot sequential systems or simultaneous systems. The density of the phosphors on the strips may be varied so as to compensate for loss of light which would otherwise result for excessive deflecting voltages between the strips, i.e. the density is greater further away from the end wall of the tube. The green phosphor layer may or may not have a thin conductive coating of metal, e.g. aluminium; if there is no coating, the layer takes up a suitable potential by secondary emission. The tube may be of glass, metal or 'glass and metal' and has electrostatic or electromagnetic deflecting means for scanning. If the strips are not edge on to the gun, means, e.g. auxiliary focussing means, must be provided for deflecting the beam just before it enters the grating to make it parallel to the strips of the grating. The tube has modulating grid, first and second anodes, and may have internal electrostatic or external magnetic focussing. The end wall of the tube may be frosted before deposition of the green phosphor to diffuse the light uniformly.