PL115780B1 - Method for adjustment of colour purity in a picture tube and device therefor - Google Patents

Description

The patent description was published: February 28, 1983 READING ROOM of the Palent Office fgUiej toczyggs ^ il.-tj Luioiij Int. CI.2H04N 9/62 H04N 9/539 Inventors: William Randolph, Robert Lloyd Barbin, Theodore Frederick Simpson, William Arthur Sonntag. : RCA Corporation, New York (United States of America) CRT Color Purity Adjustment Method and CRT Color Purity Adjustment Apparatus 1 Prior to this invention is a CRT color purity adjustment method and a CRT color purity adjustment apparatus, especially for optimization. color purity tolerances of color picture tubes by compensating for variations in recording and color purity errors caused by magnetic interactions in a television set, the magnetic field of the ground, thermal expansion of the shadow mask as well as a predetermined safety factor. The three beams of the color picture tube must be adjusted to a specific position for several reasons in order to obtain a satisfactory image reproduced on the screen of the picture tube. Color purity adjustment is required on all color picture tubes. Clarity control allows the beam to fall only on the appropriate phosphor elements corresponding to different colors. Of course, if the reproduced image is of poorer clarity, for example, a red beam may strike a phosphor element corresponding to a color green or blue and cause a false color reproduction of the image. In a color tube without matrix, the part of the beam passing through the hole in the mask The shadow area is smaller than the individual irinophore element on the screen, so that when it actually falls on the desired phosphor element, it will not excite adjacent elements of different colors. A cathode ray tube with a matrix system in which phosphor elements of different colors are separated 30 With dark protective bands, the part of the beam passing through the aperture can be larger than the phosphor element, while maintaining the purity of the colors. In both types of cathode ray tube, it is necessary to center the individual bundles on the corresponding phosphor elements to minimize the likelihood of deterioration in purity. when the bundles are moving blind It is known that purity can be adjusted in the center of the screen by repositioning two color purity magnetizing rings that are movably mounted to allow rotation around the neck of the cathode ray tube. . In the terminal regions of the cathode ray tube, cleanliness is controlled by movement along the axis of the deflection system, which causes a deviation from the axis of the beams and thereby regulates their incidence positions in the areas remote from the center of the screen. 3 916 437 a method for adjusting the purity of a color in a picture tube using a purity ring and a deflection system. The storage device used in the apparatus is programmed in a conventional manner as shown in Harris Semiconductor Catalog, August 1975, pages Me-55 to Me-57. However, difficulties may arise due to write errors when the picture tube is installed in the television receiver. These difficulties are usually caused by the action of a magnetic field in the receiver which was not present during manufacturing adjustments. These difficulties prove to be particularly burdensome and costly in those cases where the deflection system and purity rings become permanently immobilized after the cleanliness adjustment in the manufacture of the cathode ray tube. In these cases, the receiver manufacturer must either install a relatively expensive compensator in the receiver or return the cathode ray tube to the cathode ray tube manufacturer, taking into account the risk that said cathode ray tube may also exhibit cleanliness errors. In order to avoid the above difficulties due to recording errors due to the magnetic field of the receiver, the metal components are placed in different positions around the deflection system. The dimensions and positions of the metal elements are determined by a trial and error method, until the error of the cathode ray tube in the tester becomes identical to the writing error in the receiver. Because each type of receiver produced by each a receiver manufacturer usually has a specific, different magnetic field, it is obvious that the use of metal elements for all possible receiver fields is expensive, tedious, takes a long time and may not always be possible. The raster produced is deformed by the current flowing through the auxiliary deflection coils, the current being varied in a manner corresponding to the influence of the factors affecting the kinescope as a result of the correction. Corrections are made in one of the two directions through at least two consecutive vertical fields and then corrections are made in the other of these two directions through at least another two consecutive polar to reduce the required rate of change of current in the auxiliary deflection coils. The apparatus of the invention comprises a pair of auxiliary deflection coils mounted in a holder on opposite sides of the cathode ray tube, to which is attached an auxiliary power supply, including a counter counting up to 64, of which the inputs are connected to the yaw generator and the yaw generator and to the counter up to 8 and the output of which is connected to one input of the counter up to 4, the second input of which is connected to the yaw generator . One input and one output of a counter counter to 8 is connected to a controlled generator. The outputs of the counter counting up to 4 and the counter counting up to 8 are connected to at least one memory device, connected to a digital-analog converter, connected in turn to the power amplification connected to the auxiliary deflection coils. and the digital-to-analog converter is turned on a switch, the second input of which is connected to the counter output to 128, also connected to the second counter input to 64 and the second counter input to 4 and simultaneously to the deflection generator In another embodiment of the invention, the device comprises a pair of auxiliary deflection coils mounted in a holder on opposite sides of the cathode ray tube, to which an auxiliary power supply system is attached, which includes an analog generator whose first input is connected to a vertical deflection generator. and a second input is connected to the generator and the output is connected to a deflection power generator, the second input of which is connected to the first input of the analog generator, and whose output is bypassed by a detector and connected to auxiliary deflection coils. The analog generator contains a generator. of parabolic signals, the input of which is the first input of the analog generator also connected to the input of the vertical deflection signal generator, and the outputs of the generators are connected to the inputs of the signal combiner, whose output is the output of the analog generator and to the whose other inputs are connected to a parabolic signal generator and a horizontal deflection pitcher whose inputs are connected and constitute the second input of the analog generator. According to the invention, the color picture tube contains a multi-beam assembly of electron guns producing three Root electron beams, and each repeating group of luminescent elements contains three phosphor elements of different colors, lying in a vertical direction, which lie in space essentially parallel to each other and essentially perpendicularly to the direction of selecting the electron beam. The device comprises means for changing the supply periods 35 of the auxiliary deflection coils. The first and second periods of supply of the auxiliary deflection coils each comprise 128 vertical fields. The subject of the invention is shown in the embodiment examples in the drawing in which Fig. 1 shows first embodiment of a color purity adjustment device in a cathode ray tube in a block diagram and partially in a side elevational view, Fig. 2 - a second embodiment of a color purity adjusting device in a cathode ray tube in a block diagram and a partial embodiment in a side elevational view, Fig. 3 - the picture tube in the front view showing the screen divided into 32 areas, Fig. 4 - parts A rear view of the apparatus of Figs. 1 and 2, showing the working relationship of the auxiliary deflection coils to the color CRT in the apparatus of the invention, Fig. 5 - a part of the CRT screen showing the nominal incidence of an electron beam, as well as three the position of the beam deflected as a result of the effects causing the beam incidence error, Figs. 6-55 part of the CRT screen showing the total effect of the beam incidence errors in Figs. 5, Fig. 7 - graphical representation explaining how the deflection coil moves along the axis in the first direction affects the shift of the spot of incidence, as well as the power curve of the auxiliary deflection coil as a function of time, Fig. 8 - graphical representation showing how the movement of the deflection coil along the axis in the second direction affects the shift of the spot of incidence bundles, as well as the graph of the supply current to the auxiliary deflection coil as a function of time, Fig. 9 - shift of the position of the beam for the first direction and the diagram of the current required to obtain this shift, Fig. 10 - shift of the beam incidence location for the second direction and Diagram of the current required to achieve this shift, and Fig. 11 - third embodiment of the color purity adjustment device in kinescope in block diagram and partially in side elevational view. Referring to figure A, there is shown a color picture tube 10F which is attached to the holder 12 of the control circuit by an appropriate rigid mounting element / the picture tube 10 includes a screen 14 having an inner surface on which a large number of phosphor elements 16 corresponding to different colors are placed. The perforated mask 18 is positioned at a relatively matte-reflective position from the rear surface of the phosphor elements 16 to allow some of the electron beams in the cathode ray tube to pass through the openings to strike the individual phosphor elements corresponding to different colors. Variation layout 20, including the horizontal and vertical deflection coils, is attached to a mount 22, which is in turn attached to a mount 24, which is firmly attached to the balloon of the cathode ray tube '10. The fastening elements are suitably selected to allow relative movement between the biasing system 20, the fastening element 22 and the fastening element 24. Any suitable system may be used to fix the element 22 to the element 24 once it is in a satisfactory position. The static convergence unit 26 is attached around the neck of the cathode ray tube 10 at the back of the deflection circuit 20. The static convergence complex 26, which may be of known type, is used to focus electron beams, corresponding to the red, green and blue colors, in the cathode ray tube in the cathode ray tube. the central area of the screen 14. At the rear of the static convergence unit 26 is a pair of rings 28 and 30 for controlling the purity of color. These rings are magnetized along the diameter of each ring so that the rotation of the rings around the neck of the picture tube 10 will cause the three electron beams to run in the same direction. The top and bottom of the picture tube 10 are positioned and firmly attached by means of a Free appropriate components for control unit holder 12, large auxiliary deflection coils 32a and 32b. Figure 4 is a partial view of the rear of the apparatus of Figure 1, showing the working relationship of the auxiliary deflection coils 32a and 32b to the color picture tube 10. It can be seen that the deflector coils 32a and 32b lie horizontally against the opposite on the conical portion of the picture tube 10. When energized, these deflection coils create a vertical magnetic field which serves to shift the electron beams in the tube 10 horizontally. The power beam produces a magnetic field which causes the beam to shift left or right. from, the direction of flow of the supply current. The magnetic field produced by the coils 32a and 32b is an additional field to the normal deflection field 5780 6 produced by the deflection coils 20. "/" "The horizontal and vertical deflection coils 20 are electrically connected to terminals 5 on the terminal board. 34. Generator 36 provides a scan current at a vertical frequency (60 Hz) and is connected to the terminal board 34 to power the vertical coils. The horizontal oscillator 38 provides the dial current at a horizontal frequency (15, 750 Hz) and is connected to the terminal board 34 to provide a scan current for the horizontal deflection coils. As previously stated, the method of the invention includes mimicking the sources of color cleanness errors by deflecting the beams in a predetermined amount and direction in each direction. from at least two predefined rostral regions at different positions on the screen, it has been shown that the amount and direction of the beam deflection from the nominal point of incidence depending on the magnetic field scattering in the receiver or mechanical changes in the picture tube, can and usually vary from one position to the second in the ecru- ne area. As a result, any meaningful imitation of the source causing the writing error will also result in a deviation of the spot of incidence of the beam, shifting from one position to the other. In fact, imitation with the greatest fidelity to 3 requires an identical beam incident error at each location of the beam. when the number of points of incidence in the color picture tube is in the order of 1,000,000, absolute fidelity is not practical, and if the difference in error between adjacent feed locations is minimal, unnecessary. In the embodiments presented here, 32 regions with specific beam path errors associated with them have been taken as a practical approximation. FIG. Z is a front view of a picture tube 10 depicting a screen 14 divided in an 8X4 matrix pattern into 32 areas. The magnitude and direction of the beam spot error is programmed in each area, independent of the other areas. The electronic division of the raster into these areas is obtained as follows. The horizontal line waste time is substantially 63 microseconds and includes 50 microseconds for horizontal scan and 1 $ microseconds for 50 return. As a result, the eight regions in the horizontal direction, or X, will require a change every 6.25 microseconds. Moreover, if there are approximately 256 horizontal lines selected per vertical field, the four areas in the vertical direction or Y will require 55 changes every 64 lines. Note that depending on such things as vertical return time and the use of a certain number of lines for transmitted For reference signals, the actual number of dial lines may be in the order of 225 per vertical field. In this case, four areas in the vertical direction or Y, each having a substantially equal number of lines, will need to be changed every 56 lines. However, it should be noted that it is not critical that each area should contain this deer 65 lines number, therefore the above field contains -1 out of 225 lines, a change in every kbox 56 lines is still within the scope of the invention. Returning to Fig. 1, the vertical deflection generator 36 is output milking the power pulse of the vertical deflection system at the beginning of each vertical field, 1, this pulse is fed to a counter 40 counting up to 64 and to a counter 42 counting up to 4. The vertical sweep causes the counters to reset to 64 and to 4 at the beginning of each vertical field. The horizontal generator 38 outputs a power pulse to the horizontal path at the beginning of each horizontal line. This pulse is applied to a counter 40 counting to 64 and a counter 44 counting to 8, which has an output for the signals encoded in a three-bit binary system. The power pulse of the horizontal deflection system acts as a synchronizing signal on the input of counter 40 counter to 64 and serves to reset counter 44 to 8 at the beginning of each horizontal line. Counter 40 counting to 64 outputs a sync pulse fed to counter 42 counting up to 4 times for each 64 input sync pulses. The output of the controlled generator 46 is connected to a counter 44 counting to 8. The frequency of the generator is 160 kHz and the output signal acts as a synchronizing signal on the input of counter 44 counting down 8, causing changes in the state of the encoded binary output signal. every 6.25 microseconds. Counter 44 counting with generator 46a starting when counter 44 counting to 8 and ending when the counting counter -to 8 reaches the number 8. The counter counting up to 8 will give an output signal in a tri-binary binary system on three counters up to 32 words using an eight-bit memory chip (ROM) 48 for reading information only. The signal encoded in the three-bit binary system forms the address part X of the five-bit address at the input of the memory chip 48. Counter 42 counting to 4 gives an output a signal encoded in a two-bit binary system on two lines to the memory chip 48. Encoded signal In a two-bit binary system, it forms the address part Y of the five-bit address at the input of the memory chip 48. The read-only memory chip 48 gives ha output an eight-bit, two-bit coded data word on eight lines, fed to the eight-bit digital-to-analog converter with the 5ff-bit meaning. The data is determined by the sign of the digital converter output signal 50, and the remaining seven bits are determined by the size. The output of digital to analog converter 50 is fed to power amplifier 52. Power amplifier 52 supplies current to auxiliary deflection coils 32a and 32b. Before operation, each memory device 48 is programmed in a conventional manner. in order to put the correct data in each memory state. These data are obtained from a list of broken site errors in the area of incidence associated with the magnetic interaction in the reservoir, mask warp, associated with temperature variations, effects of changing the magnetic ground field of ble, or other sources the sites of beam incidence to be compensated. The direction and magnitude of the beam incident errors are recorded. In the event that the magnitude and magnitude of the supply current in the auxiliary deflection coils 92a and 92bf which current causes an equal shift of the beam location, it is known for each memory state. the appropriate digital data is programmed. For example, when the measured error in the spot of beam incidence is 25.4 microns to the left of the position of nine (01001) and it is known that the digital data word 10010000 will cause a shift of 25.4 microns per left, then 10010000 will be programmed to state 01001 in the appropriate memory chip. After programming is complete, the kinescope is powered and the raster is continuously selected. Two of the three bundles are broken, for example, those corresponding to blue and green, leaving only a red field. Counters 40, 42, and 44 are reset or initialized at the beginning of each picking of a vertical field by means of the power pulses of the horizontal and vertical deflection systems. A counter 44 counting to 8 and counter 42 counting to 4 together provide the 5-bit word 30 at the output. address (e.g. 00000) to a memory chip 48 which outputs a data word, the addresses (e.g. 10000101) being provided to the digital-to-analog converter 50. The digital-to-analog converter converts the digital data word into a system 35 is an analog signal that is fed to the power amplifier 52. The power amplifier 52 supplies a supply current to the auxiliary deflection coils 32a and 32b, the value and direction of which is a function of the eight bit data word contained in the memory chip address 00000. After a period of 6.25 microseconds has elapsed, the output of counter 44 counting to 8 changes state to e.g. 001, causing the input of the piebbit word a to memory chip 48 to obtain 00001. In other words, the token address X is advanced one count while the Y address remains unchanged. The memory chip then outputs an eight-bit data word that has been programmed to memory state 00001, with the result that the power amplifier 50 feeds the auxiliary deflection coils according to the data stored in that state. Address X continues to advance forward. - in the next period of 6.25 microseconds until the seventh (111) is reached, at which time the counter 44 counting to 8 completes the control of the generator 46. At the beginning of the next horizontal line, the counter counting to 8 is reset and the process repeats. in the event that the output of the counter to 4 stays unchanged for 64 lines, the address remains unchanged and the address states 00000 and 00111 are repeated for 64 lines. After selecting the sixty-fourth line, the counter 40 counting to 64 will output a sync pulse which causes the counter 65 to advance to 4. As a result, 115 780 10 at the start of dialing 65 for the horizontal name, address Y is shifted forward one count, and a five-bit address word is, for example, 01000. Sends of address X are forwarded eight times for each horizontal line on 64 lines, with the original address Y being left unchanged. This causes the beam incident error produced to remain substantially constant in each area defined by one eighth of the scan line in the horizontal direction and 64 lines in the vertical direction. The beam application site error varies from area to area depending on the data program in response to telling him the address of the memory chip. The final result is that the raster is effectively divided into 32 regions, each of which has an independently programmed beam incident error. When introducing the required errors in the spot of the beam, the purity of the wheels is now adjusted according to the known technique. The previously mentioned procedure is repeated for the blue field (the red and green color bands are interrupted), for the green field (the color beams are red and blue are broken) and for the white field (all the bundles run). It is possible that a skilled operator may be able to adjust the purity of the color according to this method using only the white field or a single color field. one or more fields or some combination thereof are within the scope of the invention. Adjusting the purity of the color, in the presence of beam incidence errors in the receiver according to the invention, minimizes the color purity errors in the TV receiver obtained. The method and apparatus shown in Fig. 1 are effective for compensating for a single source of purity errors. , however, they may not be effective for a large number of sources of purity errors, including receiver magnetic field interaction, shadow mask thermal expansion, effects of variations in the intensity and / or direction of the surrounding magnetic field, and other less specific sources of error. Under certain circumstances, such as the above conditions, if data are obtained from multiple sources of the purity error, or when not only the sole source of the cleanliness error is dominant, it may be required to compensate for a large number of sources of cleanliness errors at the same time. due to influences during operation, for example, magnetic interaction in the receiver, thermal expansion of the shadow mask, changes in the surrounding magnetic ground field due to the use of different positions and orientations, and other, less precise sources are added together and then as shown in Fig. 5, each source causes its own error in different areas of the raster. For example, the receiver itself may cause an error of 12.7 micrometers to the left of the nominal beam incident site 60 in the area shown in Figure 5. The error is indicated by dashed line 66. In my area, mere warping of the mask can result in a 25.4 micrometre error to the right, which is a sign of Connected dashed line 64. Variations in the surrounding magnetic field of the earth may result in an error of 12.7 micrometers to the left, also in the same area, and the cumulative error caused by the receiver and the magnetic earth piles are indicated by the dashed line 62 . *, 5 In this regard, the sum of all errors may be represented by dashed Hnia 68 in Fig. 6 This sum is very similar to that obtained with an extended bundle; consequently, this expanded bundle should be centered around a corresponding phosphor element of a given color in order to optimize the purity of the color. In this way, the beam will not overlap adjacent phosphor elements of other colors even in the presence of one or more sources of error. Accordingly, the second embodiment of the device according to the invention makes it possible to obtain optimal color purity as follows. The assembly of auxiliary coils is arranged on opposite sides of the picture tube. The picture tube is put into operation for selecting a raster on the screen of the picture tube. The auxiliary coils are energized for the beam deflection to the left of the nominal beam incidence locations by a specified distance during at least one vertical field and to the right of the nominal beam incidence location by a specified distance during at least one vertical field. shows a second embodiment of a color purity control device in a cathode ray tube in a block diagram and partially in a side elevational view. This particular arrangement introduces errors to the left and right of a certain distance in each of the 32 areas of the raster surface in the 8X4 matrix. By introducing changes to the states of the counters and the read-only memory, another number of areas may be created, for example, 25 areas in a 5X5 matrix. The errors can be programmed for one area independently of the other areas. In addition, the amount of the deviation to the left can be programmed regardless of the amount of the deviation to the right in any given area. Once programmed beam incidence errors for each area remain essentially constant throughout the entire surface. As shown in FIG. 2, the kinsecop 70 is attached to the holder 72 by an appropriate rigid fastener. The deflection and purity pattern of the picture tube 70 correspond to the identical elements 14 to 30 of FIG. 1. The top and bottom of the picture tube 70 are positioned and firmly attached by any suitable elements to the holder 72. two auxiliary deflection coils 92ar 92b. The deflection coils 92a and 92b are identical to the auxiliary deflection coils 32a and 32b of FIG. 1. When energized, these deflection coils 55 generate a magnetic field that causes the beam to shift to the left or right depending on the direction of the flowing feed current. It should be noted that despite the use of a pair of auxiliary coils 60 in the horizontal direction in the described embodiment, any suitable coil configuration may be used which produces an essentially vertical magnetic field for deflecting the beams in a horizontal direction. Fig. 1, the circuit shown in Fig. 2 uses a vertical deflection generator 96 25 30 35 40 45 1151 11 and a horizontal deflection generator 98 to provide the correct currents to the deflection circuit. In Figure 2, the vertical deflection generator 96 outputs a power pulse. of the vertical deflection system at the beginning of each vertical field, this pulse is applied to a counter 100 counting to 64 and to li Switch 101 counting to 128. The power pulse of the vertical deflection circuit acts as a synchronizing signal at the input of counter 101 counting up to 128 / This pulse also serves to reverse and counters up to 64 and up to 4 at the beginning of each vertical field. 98 outputs a horizontal power pulse at the beginning of each horizontal line. This pulse is fed to a counter 100 counting to 64 and to a counter 104 counting to 8, which outputs a signal encoded in a three-bit binary system. The forward pulse of the horizontal deflection circuit serves as a synchronizing signal at the input of the counter 100 counting counter 100. 64 and serves to reset counter 104 counting to 8 on the fence of each horizontal line. Counter 100 counting to 64 outputs a sync pulse fed to counter 102 counting to 4 once for every 64 input sync pulses. Counter 101, counting to 128, outputs a control signal to the double-input switch 105, once for every 128 pulses of power supply to the vertical deflection system. The output of the controlled generator 106 is connected to the counter 104 counting to 8. The frequency of the generator is 160 kHz and the output signal acts as a synchronizing signal at the input of counter 104 counting to 8, causing the output state of the encoded signal 35 to be changed every 6 binary counters. , 25 microseconds. Counter 104 counting to 8 outputs a control pulse which directs generator 106 to begin when counter 104 counts to 8 and ends when counter 104 reaches 8. * 40 A counter counting to 8 outputs a signal encoded in a triple binary system on three lines to the first 32 word using an eight-bit memory chip (ROM) 108 to read the information only and to the second 32 words after 45 power of eight bit read-only memory chip (ROM) 109. The memory circuits are programmed as mentioned above. The signal encoded in a three-bit binary system forms the address portion X of the five-bit address 50 on the input of the first and second memory devices 108 and 109. Counter 102 counting to 4 outputs a signal encoded in two-bit binary system on two lines to the first and second memories 108 and 109.1 55 The signal encoded in the two-bit binary system forms the address portion Y of the five-bit address at the memory chip inputs. The first memory chip 108 outputs an eight-bit binary-coded data word on eight 6 ° lines fed to the switch 105 with two inputs. The second memory chip 109 outputs an eight-bit, binary-coded data word on eight lines, fed to the second input of the switch. ¬ ka 105 with two entries. 12 A control signal from counter 101 counting to 128 causes a data word from the first memory chip 108 or a data word from the second memory chip 109 to the output of switch 105. The output of switch 105 is connected to eight lines of the eight-bit DAC 110. the significant bit of each eight-bit data word specifies the sign of the output of the digital-to-analog converter, and the remaining seven bits define the value. The output of the digital-to-analog converter 110 is connected to the power amplifier 112. The power amplifier 112 supplies current to the auxiliary deflection coils 92a and 92b. Care should be taken in programming the appropriate memory chips for the following reasons. Fig. 7a shows how movement of the deflection system along the axis in the first direction will affect the shift of the bundle loading site. The beam location on the left side of the screen will move towards the center. The beam location on the center of the screen will remain unchanged and the beam location on the right side of the screen will move towards the center. A diagram of the supply current to the auxiliary deflection coils required to compensate for this actual system motion is shown in Fig. 7b. At the start of the deflection line, a relatively large current, for example + 1A, is required to deflect the nominal beam spot into the forest. the right side of the screen to the correct distance from the center. Likewise, a relatively large current, for example + 1A, flowing in the opposite direction, is required to deflect the beam to the right side of the screen the same distance towards the center. As a result, as shown in FIG. 7b, the feed current must vary from +1A to -1A during a horizontal scan period of 50 microseconds. At. Several problems arise when starting to select the next horizontal line. This is due to the fact that at the beginning of the next horizontal line, a current + 1A is required again for a deflection lying to the left of the beam incident towards the center. This requires a switch-current from -1A at the end of one horizontal line to + 1A at the start of the next horizontal line, i.e. in the example shown here, this requires a current change of two amps during a recovery period of 13 microseconds. 8a and 8b, a similar problem arises when starting to compensate for the movement of the yaw system along the axis in a second direction opposite to the first direction. This requires the power amplifier 112 to switch from + 1A to -1A during a recovery period of 13 microseconds. The switching problem can be solved by programming the information-only memory chips so that all beam shifts induced occur in one direction with at least one vertical spider. The displacement of the incidence of the beams and the corresponding graphs are shown in Figs. 9a and 9br 10a and 10b. As shown in Figs. , the current only needs to vary from for example + 1A at the beginning of the horizontal line to zero, then 1151 13 back to + 1A at the end of the horizontal line. As a result, the current may remain equal to +1A during a recovery period of 13 microseconds. As shown in Figures 10a and 10b, the current must only vary from -1A to zero, back to 5-1A during the duration of the line. equal to 50 microseconds and may remain equal to -1A during a recovery time of 13 microseconds. In order to provide the operator with easily observable readings of detected cleanliness errors, it is desirable that shifts of the spot of the beam incident in a specific direction take place for at least two consecutive vertical fields. This will allow the operator to reproduce the purity of color more consistently in all directions. In the embodiment shown here, a shift in each direction occurs for 128 consecutive vertical fields. This means that the deviation of the incidence of the beam towards the right will take place for 128 vertical fields, the deviation of the incidence of the beam towards the left will be there was room for the next 128 vertical fields; followed by 128 vertical fields for the points of incidence of the beam to the right, and so on. As a result, the first memory chip 108 is programmed for right beam spot errors only, and the second memory circuit 109 is programmed for left beam spot errors only. After kinescope programming is complete, it is powered up and the screen is continuously selected. Two of the three bundles are broken, for example, those corresponding to the colors blue and green, and only the red area is left. Counters 100f 102 and 104 are reset, i.e. put into the initial state of selecting each vertical pile by the power pulses of the horizontal and vertical deflection systems. Counter 104 counting up to 8 and counter 102 counting up to 4 together give the output a five-bit address word ( e.g. 0000), provided to the first 40 and second memory devices 108 and 109, each of which outputs a data word contained in the address, e.g., 10000101 at the first output of the memory chip and 00000101 at the output of the second memory chip . * 5 The switch 105 with dual input transfers the data word from the memory chip to the input of the eight-bit digital to analog converter 110 for 120 consecutive vertical fields. This is determined by the counter 101 counting to 128, which counts 128 consecutive pulses of power supply to the vertical deflection circuit, then sends a signal to switch 105 with two inputs, which then connects the output of the second memory chip to the input of the digital converter. wo-analog 110. 55 After 128 vertical fields, the output of the first memory chip is re-connected to the input of the digital-to-analog converter 110. This switch takes place during the duration of the check. The digital-to-analog converter 110 processes the word of digital data appearing on its output on the analog signal that is fed to the power amplification 112. The power amplifier 112 supplies the power current to the auxiliary coils 92a and 92b, the value and direction of which are functions of an eight-bit "14" data word contained in the address of the appropriate memory chip. After a period of 6.2 microseconds has elapsed, the output of counter 104 counting to 8 changes state to e.g. 001, causing a five-digit address word to enter the memory chips to obtain 00001. In other words, address X is shifted forward one count. and the address of Y remains unchanged. Both memory chips will then output an eight-bit data word that has been programmed to memory state 00001. Depending on the state of the two-input switch 105, one of these data words will be fed to the DAC 110, the line will be amplified by the power amplifier 112 and applied to the auxiliary deflection coils 92a and 92b. Address X continues to advance for each 6.25 microsecond period until the seventh (111) is reached, at which time counter 104 The countdown to 8 ends control of generator 106. At the beginning of the next horizontal line, the counter counting to 8 is reset and the process repeats. In the event that the output of the counter counting to 4 remains unchanged for 64 lines, address Y remains unchanged and the state of address 00000 and 00111 sg repeatable for 64 horizontal lines. After 64 lines are dialed, counter 100 counting to 64 outputs a sync pulse which causes counter 102 counting to advance to 4. As a result, at the start of dialing the 65th horizontal line, address Y is shifted forward by one. and a five-bit address word is, for example, 01000. The X address states are shifted forward eight times for each horizontal line on 64 lines, with the new Y address remaining unchanged. As a result, the generated error of the delivery site error remains substantially constant in each area defined by one eight scoring lines in the horizontal direction and 64 lines in the vertical direction. As mentioned previously, the direction of the generated error in the delivery site. remains the same in all areas for 128 consecutive vertical fields. However, the value of the beam incident error varies from area to area depending on the data programmed in the address of the corresponding memory chip. The final result is that the raster is efficiently divided into 32 regions, each having an independently programmed spot error on the left and an independently programmed spot error on the right. This effectively results in an increase in the width of the beam incidence as shown in Figure 6. The purity of the color is now adjusted according to a known technique. Figure 11 shows another embodiment of the device according to the invention similar to that of Figure 1 except that the auxiliary The digital power supply of FIG. 1 has been replaced with an analog signal generator in order to obtain substantially the same effects. The vertical and horizontal power pulses from the vertical and horizontal generators 36 and 38 are fed to the analog generator 150 Pulses with a vertical frequency are applied to a parabolic generator 1521T5 790 16 and to a vertical oscillation signal generator 154. The horizontal frequency amplifiers are fed to the horizontal path parabolic generator 158, the horizontal sweep pilots generator 160, and the horizontal sweep generator 162. The output signals are parabolic and pilobular waveforms of the horizontal sweep. from the generators 152, 154, 158 and 160 to a signal adder 156. Parabolic and pilot wave generators may be of any appropriate type, such as those conventionally used to produce waveforms of the type that are used to correct pincushion distortions and correct convergence in television receivers. may be a conventional circuit capable of selectively combining any two or more of the input signals connected to each other. As a result, the output signal obtained from the signal combiner 156 is inherently capable of feeding the deflection generator 162, which is a normal quadrature, nonlinear pattern. deflection feed, and in turn produces the required scout current timed dependent on the vertical and horizontal scans to generate the required magnetic field through auxiliary coils 164a and 164b. Deterrent 165 allows the static shift often required for ground field variations and to assist in the regulation of the current produced by the dial amplifier. Such a field may introduce the required beam recording conditions at a selected position on the cathode ray tube screen, as described in connection with FIG. and then only on the right side of the screen. Such a signal is produced using the vertical frequency signal appearing during the first half of each vertical period and the horizontal frequency signal appearing during the second half of each sweep period. horizontal. Thus, the apparatus of Fig. 11 may be used to obtain similar effects to the apparatus described in reference to Fig. 1. Although the above apparatus is described in accordance with the television standards of the United States of America, European or other television standards may also be used in as a result of making proper changes to the numerical values of the counters and the generator frequency. PL

Claims (1)

Claims 1. A method of color purity control in a multi-beam color picture tube, during which the cathode ray tube is energized for the production of a raster by one of the multiple beams, the purity in the center of the raster is adjusted and the purity is adjusted at the edges of the raster, characterized by the 2.SipnpiztoiaQV ^ ^ strings ^ iR, raster produced by the current flowing through the auxiliary deflection coils, the current being varied in a manner consistent with the influence of factors influencing the cathode ray tube by correction. 2. The method according to claim The method of claim 1, characterized in that corrections are made in one of the two directions through at least two consecutive vertical fields and then corrections are made in the other of these two directions through at least the next two consecutive fields to reduce the required rate of change. current in auxiliary deflection coils. A device for adjusting the purity of the color in the kinescope, comprising a holder for supporting the kinescope and a deflection unit at a predetermined operating position relative to the kinescope, a vertical deflection generator and a horizontal deflection generator for powering a deflection system at normal frequencies of field and line deflection. for selecting a raster on the screen by at least one electron beam, characterized in that it comprises a pair of auxiliary deflection coils (32ar 32b), (92a, 92b) mounted in a holder (12), (72) on opposite sides of the picture tube to which it is attached is an auxiliary power supply, comprising a counter (40), (100) counting up to 64, the inputs of which are connected to a vertical deflection generator (36), (96) and a horizontal deflection generator (38), (98) and to the counter (44), (104) counting up to 8 and the output of which is connected to one input of the counter (42), (102) counting up to 4, the second input of which is connected to the ge a vertical deflection generator (36), (96), and one input and one output of the counter (44), (104) counting to 8 is connected to the control of the generator (46), (106), while the output of the counter ( 42), (102) counting up to 4 and counter (44), 35 (104), counting up to 8 are connected to at least one memory device (48), (108, 109) connected to the digital-to-analog converter (50 ), (110) in turn connected to the power amplifier (52), (112) connected to the auxiliary deflection coils (32a), (32b). 4. Device according to claim 3, characterized in that a switch <105) is connected between the voltage system (108) and the digital-to-analog converter (110), the second input of which is connected to the output of the counter (101) 45 counting to 128, also connected to the second input a counter (110) counting up to 64 and a second input of the counter (102) counting up to 4 and concurrently with the horizontal deflection generator (98). 5. Device according to claim The method of claim 3, wherein the color picture tube comprises a multi-beam array of electron projectors producing a three-row electron beam, and each repeating group of luminescent elements comprises three phosphor elements of different colors, lying in the vertical direction. the new one, which lies in space essentially parallel to each other and essentially perpendicular to the direction in which the electron beam is selected. 6. A device for adjusting the purity of the color in a kinescope, comprising a holder for supporting the kinescope and a deflection system at a specific working position along the cathode ray tube, a vertical deflection generator and a horizontal deflection generator for powering a deflection system with normal the field and line deflection frequencies for selecting a raster across at least one electron beam, meaning that it includes a pair of auxiliary deflection coils (164a, I64b) mounted in a holder on opposite sides of the cathode ray tube connected to an auxiliary power supply comprising an analog generator (150), the first input of which is connected to a vertical generator (36) and a second input is connected to a horizontal generator (38) and an output is connected to the geometry A generator (162) of the power supply of a deflection system, the second input of which is connected to the first input of the analog generator (150) and which This output is bypassed by a detacher (165) and connected to the auxiliary deflection coils (164a, 164b). 7. Device according to claim The method of claim 6, characterized in that the analog generator (150) comprises a vertical deflection parabolic signal generator (152), the input of which is the first input of the analog generator (150) also connected to the input of the vertical deflection parabolic signal generator (154). and the outputs of the generators (152, 154) are connected to the inputs of the signal combiner (156), the output of which is the output of the analog generator (150) and to the other inputs of which are connected a horizontal deflection parabolic signal generator (158), and the horizontal deflection pilot signal generator (160), the inputs of which are coupled and constitute the second input of the analog generator (150). 8. Device according to claim 6. The method of claim 6, wherein the color picture tube comprises a multi-beam electron beam assembly producing three electron beams, and each repeating group of luminescent elements comprises three luminescent elements of different colors, lying in a vertical direction, which lie in space, essentially parallel to each other and essentially perpendicular to the direction of selecting the electron beam. 9. Device according to claim The apparatus of claim 3, characterized in that it comprises means for changing the feeding periods of the auxiliary deflection coils. 10. Device according to claim The method of claim 9, characterized in that the first and second periods of energizing the auxiliary deflection coils each comprise 128 vertical fields. FIG. 115 780 FIG. 11. 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