MXPA97000733A - Device for correction of differential coma error in catodi ray tubes - Google Patents

Abstract

The present invention relates to a device for correction of negative differential coma error in convergence-free deflection coils. The deflection coil encloses a portion of a cathode ray tube including a neck portion of the cathode ray tube and includes: a separator around which a horizontal deflection coil is provided to provide a horizontal magnetic deflection field; from which a vertical magnetic deflection coil is wound, the core partially surrounds the separator, and a rear cover which fixes the deflection coil to the cathode ray tube, the back cover is placed around the neck of the cathode ray tube and has a first side facing the direction of the cathode ray tube screen and resting against a rear end of the separator. According to the present invention, the arcuate branches that are preferably "C" shaped and have internal radii that are parallel to the neck of the cathode ray tube, are placed on the first side of the rear cover and are preferably centered in a first axis of the neck of the cathode ray tube and this axis of the cathode ray tube screen. The use of these derivations in the form of "C" is found to correct the negative differential coma error introduced by the deviation coil exempt from convergence.

Description

"DEVICE FOR CORRECTION OF DIFFERENTIAL COMA ERROR IN CATHODIC RAYS TUBES" BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This invention relates to deflection coils. More particularly, it relates to a device of a deflection coil for correction of the negative differential coma edrror in color cathode ray tubes. 2. GENERAL BACKGROUND It is known that cathode ray tube (CRT) devices, such as those included in certain television receivers, are formed by scanning an electron beam through a photon emitting surface (e.g., phosphorescent) of according to the video signals admitted to one or more of the electronic cannons. In color CRTs there can be three in-line electronic cannons, each providing red, green and blue video signals, or a single multi-beam electronic cannon that has three cathodes to provide these signals. Images in different colors are formed by different compositions of these red, blue and green signals. A deflection coil having two pairs of rolls, is preferably placed around the funnel end of the cathode ray tube, a pair of rolls, each to deflect the electronic beams with the correct frequencies in both the horizontal direction (the roll horizontal or "line") and in the vertical direction (the vertical or "box" roll). The electronic beams deflected in this way collide with the phosphor points on the CRT screen resulting in a displayed video image. Deviation coils can be divided into three categories; self-convergence (SC) or convergence-free deflection (CFD) coils, non-self-converging (NSC) or non-convergence (non-CFD) deviation coils and pin-free deflection coils (PFD). The main difference between the three types of deflection coils is the amount of correction for errors and distortions that is achieved by the deflection coil itself, without the aid of an additional corrective circuit. For example, the main difference between the non-convergence deviation coil (non-CFD) and the non-convergence coil (CFD) is that the first includes a circuit known as a dynamic convergence circuit to correct certain errors and distortions that will result in the image presented on the CRT screen being left uncorrected. By contrast, the deflection-free deflection coil (CFD) (see, for example, the deflection coil 20, Figures la - le) does not include this circuit in the corrections of the aforementioned errors and distortions in the CRT image. They are usually achieved through the manipulation of the horizontal roll wires of the deflection coil. (Even with the CFD deflection coil there will still be some residual distortion that must be taken care of through external devices, however, the pin-free deflection coil (PFD) corrects all errors and distortions without the help of any external corrective devices ). Even though the dynamic convergence circuit provides good correction for certain of the incorrect convergences and errors mentioned above, it adds additional cost. Therefore, it is often desirable to eliminate the dynamic convergence circuit and provide a "non-convergence" (CFD) deflection coil. It has also been found to be economical and, therefore, desirable to be able to use the same television chassis for more than one type of deflection coil; for example, in the case of the present invention, it was found economical for a given television chassis to be able to divide both the non-CFD shunt coil and the CFD shunt coil. Therefore, it is desirable to provide a CFD deflection coil that would be interchangeable with a non-CFD deflection coil with the same television chassis and, therefore, be able to be driven by the same television chassis. However, as will be discussed in detail in the following paragraphs, this interchangeability requires that the deflection sensitivity and the static electrical parameters of both deflection coils are essentially identical, thus also requiring that the geometry of both deflection coils and rolls are identical. This was found to impose several restrictions on the design of the interchangeable deflection coil as explained in the following paragraphs. (Although the following discussion will be made with respect to the interchangeability of a CFD deflection coil with a non-CFD one, it will be understood that the device of the present invention is not limited and can be used in any of the above-discussed types of coils. of deflection and / or in any situation where it is desired that a deflection coil be interchangeable with another deflection coil within the same television chassis). As briefly mentioned above, several factors if left uncorrected will result in errors and distortions in the resulting image presented on the CRT screen. For example, if a uniform field (generally formed of the first harmonic at a specific frequency) is provided by both vertical and horizontal rolls 25, 30 respectively, the resulting geometric frame will be pincushioned in both the north / south directions (N / S) 45, such as east / west (E /) 50, as a direct result of the non-linear properties of the magnetic deviation and the shape of the CRT screen 40 (Figure 2). Furthermore, under the presence of a uniform magnetic field, the red and blue beams 52, 54, respectively, which converge towards the center 55 of the CRT screen 40 will be caused to over-converge at the clock positions 3 and 9 ( 3/9) (60, 65, respectively) and at the clock positions 6 and 12 (6/12) (70, 75, respectively) (Figures 2 and 3). This condition is referred to as the wrong average Red-Blue (or APH) horizontal convergence at the 3/9 clock position, and the wrong vertical-Red-Blue (or APV) convergence at the 6/12 clock position. The pattern due to the incorrect convergence of red, blue, and blue rays 52, at position 60, 65 of clock 3/9 (which is very important in terms of the present invention) is shown in Figure 4. (The lines of dashes diagrammatically represent the pattern due to red beam 52, while the solid line diagrammatically represents the pattern due to blue beam 54). In order to converge the red and blue beams 52, 54 at the position 60, 65 of clock 3/9, the red beam 52 must deviate more than the blue beam 54 along the x axis, and therefore, must undergo a more intense magnetic field. In general, the correction of the incorrect convergence 3/9 as well as the N / S pincushion of the geometric grid is achieved by introducing a magnetic field of horizontal pincushion shape (Figure 5) where the field strength increases to along the x axis of the deflection coil in the direction of the arrows as shown in Figure 5. As mentioned above, in the non-CFD deflection coils, this field can be created through the use of a Dynamic quadropole that is included in a dynamic convergence circuit. As known to those skilled in the art, the dynamic quadropole is driven with a stream having an essentially parabolic shell to provide varying amounts of correction through the different parts of the frame as necessary. However, again, in the CFD deflection coils (such as that shown in the Figures above) there is no dynamic convergence circuit and the only way to create the aforementioned pincushion field and, therefore, correct the Incorrect APH convergence is by manipulating the wires of the roll horizontally or away from the x-axis (see Figure 1). As usual, the movement of the winding distribution of the coils of the horizontal roll 30 away from the x axis and towards the axis and creates a field in the form of a barrel or tubular; on the contrary, moving the winding distribution away from the y-axis and towards the x-axis creates a more pincushion-shaped field. A difficulty encountered in correcting errors and incorrect convergences in the CFD deflection coil is that, in general, the only way by which the incorrect APH convergence is corrected is to manipulate the horizontal curls to create the additional pincushion field. once the incorrect APH convergence has been corrected, and an additional incorrect convergence is introduced that must be corrected separately. More specifically it will be appreciated by those skilled in the art that the introduction of this horizontal field of pincushion shape tends to result in the sub-deviation of the green (G) 53 beam compared to the average deviation of the red and blue beams (APH) 80, resulting in a pattern exhibited as shown in Figure 7. This incorrect convergence of the green beam 53 with respect to the average convergence of the red and blue beams 80 is alternatively known as "coma" or as "convergence" wrong horizontal central frame "(HCR). Finally, there are two other incorrect convergence parameters known in the industry such as the incorrect convergence CCV (vertical cross-corner) and incorrect convergence YBH (horizontally curved Y), which together with the incorrect convergence APH are interdependent incorrect convergences that must also be corrected . (Of course, there are other distortions and incorrect convergences that may occur but those discussed in the foregoing are the most important for the purposes of the present invention). In general, the designer of the deflection coil tries to minimize these parameters by altering the geometry (eg, length, diameter, etc.) and the relative positions of the rolls of the deflection coil. The previously discussed correction methods of the incorrect APH convergence and the incorrect convergence due to interdependent CCV / YBH / APH need the alteration of the roll geometries of the deflection coil and / or positions in a certain way. However, these methods run in direct contradiction to the interchangeability requirement of the present invention; that is, that the static electric and deviating sensitivity parameters of the CFD and non-CFD deflection coils must be essentially identical and, therefore, the geometry of the deflection coils and CFD and non-CFD rolls must be identical Therefore, in the present invention, in order to correct these incorrect convergences without changing the geometries of the deflection coil as would generally be done, it was found necessary to move the core 85 of the deflection coil (and therefore both, the vertical roll 25 (see Figures la-le) approximately one millimeter (lmm) through the separator 90 to the end 92 of the funnel of the deflection coil 20 CFD. However, moving the core 85 and the vertical roll 25 towards the end 92 of the funnel of the deflection bobbin 20 results in a significant increase in the incorrect HCR convergence. In addition, it was found that the incorrect HCR convergence was approximately one (1 mm) more negative (ie, greater) at the corners of the screen than on the x-axis (Figure 7) creating a negative differential error or? HCR. (As shown in Figure 7, the dashed line diagrammatically represents the pattern due to HCR, while the alternate dashed / dotted line diagrammatically represents the pattern due to HCR when the core 85 moved toward the 92nd end of the funnel. the deflection coil 20. As seen in Figure 7, the HCR is greater or more "negative" at the corners of the screen 40. This is the? HCR 95). Several devices and methods of the prior art have been proposed to correct the HCR, including manipulation of the roll distribution of the horizontal roll, the use of a dynamic hexapolo (or "comma coil") and rectangular permeable shunts placed between the rear cover and the upper part of the separator of a deflection coil. However, it was found that none of these proposed correction devices / methods could be used to correct HCR in the present invention. Therefore, it would be desirable to provide a device that corrects the negative differential coma error caused by the deflection coil that is interchangeable by another deflection coil within the same television chassis, in particular, it would be desirable to provide a device that can correct the negative differential coma error caused by the CFD deflection coil that is interchangeable with a non-CFD deflection coil within the same television chassis and, therefore, capable of being driven by the same television chassis.

COMPENDIUM OF THE INVENTION Accordingly, an object of the invention is to provide a novel deflection spool. It is also an object of the invention to provide a less expensive deflection spool. Another object of the invention is to provide a deflection coil that is interchangeable with a non-CFD deflection coil within the same television chassis and, therefore, capable of being driven by the same television chassis. Still another object of the invention is to provide a deflection coil CFD which is interchangeable with a non-CFD deflection coil within the same television chassis and which has the same electrical, static and deflection sensitivity parameters as the non-CFD deflection coil. CFD.

A further object of the invention is to provide a device for a deflection coil that is interchangeable with a non-CFD deflection coil within the same television chassis, the device being capable of correcting the various incorrect convergences resulting from this CFD deflection coil. interchangeable, including the negative differential coma error (? HCR). Still another object of the invention is to provide a deflection coil which is interchangeable with a non-CFD deflection coil within the same television chassis and which has a device which is capable of correcting the various incorrect convergences resulting from this deflection coil. Exchangeable CFD, including incorrect APH convergence and incorrect convergence due to the interdependent parameters CCV / YBH / APH without changing the geometries of the deflection coil and the rolls of the deflection coil. Therefore, in accordance with one aspect of the present invention, there is provided a device for correction of the incorrect convergence of differential negative coma of the type caused by a deflection coil which is used to converge at a point on the emitting display. photons, a plurality of electronic beams generated by the cathode ray tube, the cathode ray tube has a screen and a neck extending in a direction away from the screen. The deflection coil encloses a portion of the cathode ray tube including a portion of the cathode ray tube neck and includes a spacer around which a horizontal deflection coil is wound to provide a horizontal magnetic deflection field, a core around which a magnetic field winding and a vertical deflection coil to provide a vertical magnetic deflection field, surrounding the core separator and also includes a back cover to secure the deflection coil in the cathode ray tube, leaving the rear cover around the neck of the tube of cathode rays and having a first side facing that direction of the screen and resting against a rear end of the separator. The device generally comprises first and second arcuate taps which are preferably "C" shaped and which are placed on the first side of the back cover. The first and second branches are in the form of a "C", each preferably having internal radii that are parallel to the curvature of the neck of the cathode ray tube and also each one is preferably centered on a first axis of the neck of the ray tube. cathode, this axis being parallel to the axis of the cathode ray tube screen. In accordance with other aspects of the present invention, each first and second arcuate leads are made of ceramic and surround an angle distance of up to 120 ° C around a first axis of the neck of the cathode ray tube. In accordance with yet other aspects of the present invention, each of the first and second arcuate taps is placed in a slot in the first side of the back cover and fixed thereto with a synthetic resin and rubber rubber. The particularities of the present invention which are believed to be novel will be pointed out with particularity in the appended claims, however, the invention itself can be better understood by reference to the following description together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The figures respectively are a rear elevational view of a deflection coil of the type used with the device of the present invention as seen from one end of the coil that is intended to be oriented towards the electron gun assembly of the a cathode ray tube, a side elevation view of this deflection coil and a front elevation view of this deflection coil; Figure 2 shows the pincushion distortion of North / South (N / S) and East / West (E / W) of the geometric pattern of a cathode ray tube screen; Figure 3 shows the incorrect convergence of the red and blue beams (incorrect APH convergence) from an electron gun assembly under the presence of a uniform magnetic field; Figure 4 shows a diagram representing the pattern on a screen of the cathode ray tube resulting from the incorrect APH convergence of Figure 4; Figure 5 shows a diagram illustrating the configuration and intensity of a pincushion magnetic field; Figure 6 shows a diagram representing the pattern on a cathode ray tube screen resulting from the sub-deflection of the green beam from an electron gun assembly with respect to the average deviation of the red and blue beams from a barrel assembly electronic, or the incorrect convergence of the horizontal central frame (incorrect HCR convergence) that occurs with the introduction of the pincushion magnetic field of Figure 5; Figure 7 shows a diagram representing the pattern in a cathode ray tube resulting from the incorrect HCR convergence and the incorrect negative differential convergence or the wrong HCR convergence, both of which occurred as a result of moving the core and the roll vertical deflection of the deflection spool of the present invention through the separator of that deflection spool; Figure 8 shows a diagram illustrating the configuration and intensity of a tubular magnetic field; Figure 9 shows an embodiment of the arcuate leads of the present invention; and Figures 10a to 10c show three views of the positioning of the arcuate branches in Figure 9 in the rear cover of the deflection coil of Figures a to d, these views respectively being a front elevation view of the back cover, as seen from the end of the coil that is intended to be oriented away from the electron gun assembly of a cathode ray tube, a side elevation view of this back cover and a front elevation view of this cover, which is intended to be oriented towards the electron gun assembly of a cathode ray tube.

DETAILED DESCRIPTION OF THE INVENTION As stated above it was desired that one type of divert coil be interchangeable with another type of divert coil within the same television chassis and especially in the present invention that both the non-CFD shunt coil and the CFD shunt coil were able to be driven by the same television chassis and therefore were interchangeable. Again, however, this interchangeability requires that the static electric and deviating sensitivity parameters of the CFD and non-CFD deflection coils be essentially identical, thus requiring that the geometry of the CFD and non-CFD deflection coils CFD and the rolls were identical as will be discussed in the following paragraphs. (Again, even though the following distribution will be related with respect to the CFD and non-CFD deflection coils, which will comprise that the device of the present invention is not limited in this manner and can be used in any of the types of deflection coils discussed above, and / or in any situation where it is desired that a deflection coil be interchangeable with another deflection coil within the same television chassis., such as the television receivers of 81.28 centimeters, the deflection coil is part of the deviation circuit, the last of which is a tuned inductive circuit. As part of the tuned circuit, the deflection circuit "sees" the deflection coil as a combination of inductances and resistors and, therefore, it is these values which are the most important parameters of the deflection coil in terms of the circuit of deviation. In particular, the power consumption, the linearity, deviation sensitivity of the deviation circuit are directly related to the inductance values of the deviation coil. For example, if a non-CFD deviation coil having a specific deviation sensitivity is replaced in the same television chassis with a CFD deviation coil (see e.g., FIGS. The deviation that is greater than that of the non-CFD deviation coil (ie, the CFD deviation coil required less power or energy to deflect the electron beams through the cathode ray tube screen), is separate from the chassis Television that dynamically adjusts the size of the frame may not be able to control the overshoot of electronic beams and, therefore, would not be able to create a frame that is too small to fit on the screen of the cathode ray tube . In this way it will be appreciated that the deflection sensitivity of the CFD and non-CFD deflection coils should be the same. In addition, a requirement with respect to the identical deflection sensitivities imposes significant restrictions on any of the changes in the geometry of the deflection coil CFD relative to the non-CFD deflection coil. More specifically, it is known that the deflection sensitivity is a function of several parameters including the length, thickness and volume of the roll (or rolls) in this case, of the deflection coil; and therefore, any alteration in the values of these parameters will affect the deviation sensitivity. As stated above, however, this is undesirable and will be driven by the same television chassis, the two deflection coils (CFD and non-CFD). Therefore, in order for a CFD deflection coil to be interchangeable with a non-CFD deflection coil within the same television chassis and to be driven by the same television chassis, the coil deflection sensitivity is required. CFD and non-CFD deflection should be the same and the roll geometry of the CFD deflection coil be essentially identical to that of the non-CFD coil. However, it is again known that the only way to create the horizontal pincushion field necessary to correct the wrong average horizontal Red-Blue (APH) convergence (see Figure 4) created by the CFD deflection coil, is by manipulation of the horizontal roll wires towards and away from the x and y axes. Again, in general, the movement of the winding distribution of the horizontal roll away from the x-axis and toward the y-axis creates a tubular-shaped field; on the contrary, moving the winding distribution away from the y axis and towards the x axis creates a field of greater pincushion shape. Furthermore, as noted above, the introduction of a horizontal field of pincushion tends to result in incorrect convergence of the central to horizontal (HCR) frame). A difficulty encountered in correcting errors and incorrect convergences in a CFD deflection coil (eg, Figures la - le) is that, in general, the only way by which the incorrect APH convergence is corrected is to manipulate the horizontal curls 30 to create the necessary pincushion field once the incorrect APH convergence has been corrected, the resulting incorrect HCR convergence is "fixed" and must be corrected separately. However, as stated above, due to the requirement that the deflection sensitivity and, therefore, the deflection coil in the roll geometries remain the same between the CFD and non-CFD deflection coils, no changes can be made. additional in the coils of the roll of the deflection coil CFD. Furthermore, as disclosed in the foregoing, it has been found that there are two other parameters of incorrect convergence that are known in the field as CCV (vertical corner crossing) and YBH (horizontal curve Y) that together with the incorrect convergence parameter APH are for the most part constant and unalterable for a given roll geometry and a relative position of the horizontal and vertical rolls of a deflection coil. Each of these three parameters are interdependent so that the alteration of one parameter necessarily alters the other parameters. As a rule of thumb, a deviation coil designer usually tries to minimize these three incorrect convergences by altering the geometry of the coil and the relative position of the horizontal and vertical coils of a bias coil. Again, however, due to the requirement of the deflection sensitivity and, therefore, the geometries of the deflection coil and the roll remain the same and the deflection coils CFD and non-CFD can not be made any change of the roll of the CFD deflection coil. Thus in the present invention, in order to correct the incorrect APH convergence and the incorrect convergence due to the interdependent parameters CCV / YBH / APH, without changing the geometry of the deflection roll as it is generally found to be necessary moving the core 85 of the deflection coil (and, therefore, the vertical roll 25) approximately one millimeter (1 mm) through the separator 95 to the end 92 of the funnel of the deflection coil 20 CFD. (Although preferably the separator and the core of the non-CFD deflection coil are used to ensure identical coil geometries and, therefore, similar deviation sensitivity, it will be appreciated that a new coil spacer and core can be designed. 20 of CFD deviation taking into account the restrictions with respect to the roll geometries and the parameters of the static electric and deviation sensitivity). However, moving the core 85 and therefore, the vertical roll 25 towards the end 92 of the funnel of the deflection coil 20, caused a significant increase in the incorrect HCR convergence. (Figure 6). That is, the incorrect HCR convergence became more negative. This increase in the incorrect convergence HCR occurs as a result of the fact that as the vertical roll 25 moves towards the front of a deflection coil 20 (i.e. towards the end 92 of the funnel) the stray field emanating from the Vertical roll 25 is reduced. Typically, it is this stray vertical field that is used to decrease the incorrect HCR convergence. In this way moving the core 85 and the vertical roll 25 towards the front of the deflection coil 20 reduces the available stray field to correct the incorrect HCR convergence and the latter necessarily increases. In addition to the incorrect total HCR convergence, however, it was found that the incorrect HCR convergence was approximately one millimeter (1 mm) more negative (ie, greater) at the corners of the screen than on the x-axis (Figure 7) , creating a differential error or? HCR 95. This differential error does not occur frequently during the design of deflection coils and arises partly as an indirect result of the requirement that the CFD deflection coil 20 have identical parameters of both deviation sensitivity as static electricity as the non-CFD deflection coil.

It is known that to correct the incorrect HCR convergence a horizontal tubular field (Figure 8) can be introduced at the rear end of the deflection coil 20. In the tubular field opposite the pincushion field, the resistance of the field decreases along the x axis as shown by the direction of the arrows in Figure 8. In this way, in the center of the cathode ray tube screen , the green beam 53 experiences a more intense field (and consequently a greater force) than the red, blue, and 52 beams, respectively. This effect continues along the x axis and therefore, the green beam 53 deviates further along the x axis than the red, blue or blue beams 52, 54, respectively. Various prior art methods and methods have been proposed to provide this tubular field. As stated above, a first proposal would require manipulation of the winding distribution of the horizontal roll 30. Again, the movement of the roll distribution of the horizontal roll 30 away from the x-axis and towards the y-axis creates a field of horizontal shape. A second proposal would be the use of a known dynamic hexapolo (or "comma coil") mounted on the top and bottom of the back cover 35. Each roll of the dynamic hexapolo is connected in series with the half of the horizontal roll 30 thus creating a field in tubular form with the same frequency and phase of the hexopolo. As is known, the amount of correction provided by the dynamic hexapolo is determined by the number of turns of wire in each half of the horizontal roll 30. Finally, rectangular permeable shunts can be placed between the rear cover 35 and the rear roll windings (not shown) of the spacer 90 to re-configure the stray vertical field and improve the horizontal field at the rear of the deviation coil 20 . Although these propositions may be suitable for correcting the incorrect HCR convergence, none can be used to correct HCR 95 in the present invention. More specifically even though the alteration of the horizontal winding distribution can be used to correct to a certain degree? HCR 95, doing so causes undesired effects including other incorrect convergences, such as incorrect horizontal APH convergence (Figure 4) that can not be corrected in no other way. The additional alteration of the roll geometry affects the deflection sensitivity which, as noted above, is undesired if the CFD deflection coil is to be interchangeable with the non-CFD deflection coil. Rectangular leads can be used to completely correct the HCR, but they will generally be found to have no effect on? HCR 95. Finally, the addition of a dynamic hexapolo is undesirable since it adds significantly to the cost of the deviation coil and is more difficult to manufacture and, therefore, undesirable from a manufacturing point of view. However, in accordance with the present invention, it has been found that the arcuate branch devices 100 (FIG. 9) placed within the rear cover 35 of the CFD deflection coil 20 could be used to correct the differential negative error,? HCR 95 More specifically and with reference to Figures 10a to 10c, it was found that the placement of two "C" shaped bypass devices 100 inside the rear cover 35 of the CFD deflection bobbin 20 and against the back of the separator 90 and, therefore, the rear end turns of the horizontal roll 30 could be used to correct the? HCR 95. As seen in Figures 10a to 10c, the arcuate leads 100 are preferably placed within the interior of the rear cover 35 so that when the rear cover 35 is positioned above the neck 105 of the cathode ray tube (shown in dashed line), the arcuate leads 100 rest on the rear parts of the separator 90 and, therefore, the rear end turns of the horizontal roll 30. As shown in Figure 9, each of the arcuate leads 100 is preferably "C" shaped having an internal radius 110 that is preferably parallel to the curvature of the neck 105 of the cathode ray tube. Each of the leads 100 is also preferably centered on the x axis (Figure 10a) which is parallel to the axis of the screen 40 of the cathode ray tube. In the case of the deflection coil 20 shown in the Figures, the, each branch 100 preferably surrounds an angle up to 120 ° around the neck 105 of the cathode ray tube, with 120 ° resulting in the optimum correction of HCR and? HCR 95 and, therefore, being preferable. The arcuate leads 100 are preferably fabricated from a ceramic having a permeability value of 1000 (ie, μr = 1000) such as H4M ceramic that can be purchased from TDK Corporation, 6165 Greenwich Drive, Suite 150, San Diego, California, 92122. (Although a certain cost advantage is obtained by using derivations that are made of rolled steel, it was found that these leads provided less effective correction of the? HCR).

In one embodiment, the arcuate leads 100 are fixed with a synthetic resin and rubber rubber (not shown) within a groove 115 in the back cover 35 (Figure 10b), but any device other than metal or other methods and devices non-metallic fasteners for attaching the shunt 100 may be used, in a similar manner even when the slot 115 allows quick and accurate positioning of the shunts 100 during the manufacturing process this slot 115 is not necessary and, therefore, taps 100 may placed in relation to the flush with the rear cover 35. An acetate cloth tape (not shown) may be attached to the top of the shunts 35 to retain them in place, while the rubber is dried; however, it will be appreciated that this tape is not necessary for the proper functioning of the present invention. The "C" shaped derivations 100 were found to correct the? HCR 95 in two ways. First extending the curvature of the leads 100 closely around the neck 105 of the cathode ray tube (Figures 10a to 10c) plus the above-mentioned missing vertical magnetic field is captured and routed to the corners of the screen 40 of the cathode ray tube in where more is needed for the correction of? HCR 95. In addition the curvature of the 100-shaped "C" leads provides a greater tubular effect at the corners without changing the tubular effect near the x-axis. This results in a more positive change in the horizontal comma screen at the corners of the screen 40 of the cathode ray tube at positions 60, 65 of the clock 3/9 respectively, thus relieving the differential error in HCR (i.e. ,? HCR). Therefore, the aforementioned arcuate leads 100 allow a lower cost CFD deflection coil that is interchangeable with a non-CFD deflection coil within the same television chassis, the leads 100 being able to correct the various incorrect convergences resulting from the deflection coil CFD including the incorrect convergence APH and the incorrect convergence due to the interdependent parameters CCV / YBH / APH without requiring any alteration in the geometries of the deflection coils and the rolls of deflection coil. It will be appreciated that even though the arcuate leads are preferably "C" shaped and have internal radii parallel to the curvature of the neck of the cathode ray tube this is not necessary for the present invention in order to provide the correction of the? HCR. For example, it is to be expected that an arcuate branch having an outer radius that is greater than the inner radius provides adequate correction of the? HCR. that is, it is expected that arcuate taps having distant flared ends increase the tubular effect and retain the stray vertical field and will also provide proper correction of? HCR with the specific deflection coil shown in Figs. Furthermore, it is to be expected that arcuate taps having internal radii which are not parallel to the curvature of the neck of the cathode ray tube may provide? HCR correction in certain deflection coil designs. Also, it is to be expected that the angle around the neck of cathode ray tube that each of the arcuate leads 100 also surrounds will depend on the specific design of the deflection coil used as well as on whether the internal radius 110 of each of the leads 100 arched is parallel to the curvature of the neck 105 of the cathode ray tube. In this way, if a deflection coil in a design other than that shown in the Figures is used, it may be necessary to increase or decrease the angle around the neck of the cathode ray tube covering the arcuate branch 100. Therefore, as noted above, even when the arched branches are preferably "C" shaped and surround an angle of 120 ° with respect to the neck of the cathode ray tube, this design is not intended to present a limitation for the present invention. Therefore, it is clear that in accordance with the present invention, a mode that completely satisfies the objects, sights and advantages is indicated above. Although the invention has been described in conjunction with specific embodiments it is evident that many alternatives, modifications, permutations and variations will become apparent to those skilled in the art in view of the foregoing description. For example, even though the above discussion was with respect to the interchangeability of a CFD deflection coil with a non-CFD, the device of the present invention can be used on any type of deflection coils and / or in any situation where I wanted a deflection coil to be interchangeable with another deflection coil inside the same television chassis. Second, even though it was found that "C" shaped branches that span a 120 ° angle around the neck of the cathode ray tube with respect to the neck center of cathode ray tubes provided the best correction of? HCR, it is it is expected that the angle around the neck of the cathode ray tube with respect to the center that each one of the derivations covers, will depend on the specific design of the deflection coil used and on whether the curvature of the internal radii of the leads is parallel to that one. of the neck of cathode ray tubes and, therefore, the angular scale pointed out in the foregoing is not intended to be considered as a limitation of the present invention. Further, even when the derivations in the present invention were fixed to synthetic resins and rubber rubber within the backshell any non-metallic device or other non-metallic methods and devices for attaching the leads may be used. Also, even when the shunts used in the present invention were made of H4M ceramic and provided the best HCR correction, other ceramics and similar materials, such as rolled steel, can be used. Finally, it is to be expected that the additional flare of the arcuate leads at the far ends will additionally improve the correction of? HCR due to the reasons stated above. Other modalities will occur to those skilled in the art. Accordingly, it is intended that the present invention encompass all of these alternatives, modifications and variations that fall within the scope of the appended claims.

Claims (33)

R E I V I N D I C A C I O N E S:

1. A device for correction of incorrect convergence or negative differential coma of the type caused by a deflection coil used to converge at a point on the photon emitting screen, a plurality of electron beams generated by the cathode ray tube, The cathode ray tube has a screen and a neck extending in a direction away from the screen, wherein the deflection coil encloses a portion of cathode rays, including a portion of the neck of the cathode ray tube, and wherein the Deflection coil includes a separator around which a horizontal deflection coil is wound to provide a horizontal magnetic deflection field, a core around which a vertical deflection coil is wound to provide a vertical magnetic deflection field, the core surrounds the separator and where the deflection coil is fixed to the cathode ray tube by a to the rear cover, the rear cover is placed around the neck of the cathode ray tube and has a first side facing the direction of the screen and resting against a rear end of the separator, the device comprises a plurality of arcuate leads placed in the first side of the back cover for the correction of incorrect convergence of the negative differential comma.

2. The device according to claim 1, wherein the arcuate branches are in the form of "C" and each has internal radii that are parallel to the neck of the cathode ray tube.

3. The device according to claim 2, wherein the branches in the form of "C" each is centered on a first axis of the neck of the cathode ray tube, the first axis being parallel to an axis of the tube screen of cathode rays.

The device according to claim 1, wherein each of the arcuate branches surrounds up to a 120 ° angle around the neck of the cathode ray tube.

The device according to claim 3, wherein each of the "C" shaped leads surrounds an angle of 120 ° around the neck of the cathode ray tube.

The device according to claim 3, wherein the deflection coil is a deflection coil free of convergence.

7. The device according to claim 1, wherein each of the arcuate branches is made of ceramic.

The device according to claim 7, wherein the permeability of the ceramic is 1000.

9. The device according to claim 1, wherein each of the arcuate branches is made of rolled steel.

The device according to claim 1, wherein each of the arcuate taps is placed in a slot in the first side of the back cover.

The device according to claim 10, wherein each of the arcuate branches is fixed in the groove with a synthetic resin and a rubber rubber.

The device according to claim 1, wherein each of the first and second taps has flared ends to further increase the correction of the negative differential coma error.

13. A deflection coil for use with a cathode ray tube that includes an electron gun means for generating a plurality of electronic beams of the type used to converge at a point on the photon emitter screen, a plurality of electron beams generated by the cathode ray tube, the cathode ray tube has a screen and a neck extending in a direction away from the screen where the deflection coil encloses a portion of the cathode ray tube including a portion of the neck of the ray tube cathode, the deflection coil comprises: a horizontal deflection means including a separator having a front and rear end and around which a horizontal deflection coil is wound to provide a horizontal magnetic deflection field; a vertical deflection means including a core around which a vertical deflection coil is wound to provide a vertical magnetic deflection field, the core surrounds the separator; a rear cover that fixes the deflection coil on the cathode ray tube, the back cover is placed around the neck of the cathode ray tube and has a first side facing the direction of the screen and resting adjacent to / against the rear end of the separator; and an arcuate bypass means positioned on the first side of the rear cover for the correction of incorrect convergence of the differential negative coma.

The diverting coil according to claim 13, wherein the arcuate branch means comprises first and second "C" shaped branches each having an internal radius which is parallel to the neck of the cathode ray tube .

The diverting coil according to claim 14, wherein each of the first and second "C" shaped shunts are centered on a first axis of the neck of the cathode ray tube, the first axis being parallel with the shaft of the cathode ray tube screen.

16. The diverting coil according to claim 13, wherein the arcuate bypass means surrounds up to a 120 ° angle around the neck of the cathode ray tube.

The diverting coil according to claim 15, wherein each of the first and second "C" shaped shunts surround an angle of 120 ° around the neck of the cathode ray tube.

18. The diverting coil according to claim 13, wherein the arcuate bypass means is made of ceramic.

19. The deflection coil according to claim 18, wherein the permeability of the ceramic is 1000.

The deflection coil according to claim 3, wherein each of the arcuate bypass means is made of steel. laminate.

The diverting coil according to claim 14, wherein each of the first and second "C" shaped shunts is placed in a slot in the first side of the rear shroud.

22. The diverting coil according to claim 21, wherein each of the first and second shunts is fixed in the slot with a synthetic resin and rubber rubber.

23. A deflection coil according to claim 14, wherein the first and second "C" shaped taps have flared ends to further increase the correction of the error of the differential negative comma.

24. In a television receiver, a deflection coil for use with a cathode ray tube including an electron gun means for generating a plurality of electronic beams of the type used to converge at a point on a photon emitting screen, a plurality of of electronic beams generated by the cathode ray tube, the cathode ray tube has a screen and a neck extending in a direction away from the screen where the deflection coil encloses a portion of the cathode ray tube including a portion of the cathode ray tube. cathode ray tube neck, the deflection coil comprises: a horizontal deflection means including a separator having a front and rear end and around which a horizontal deflection bobbin is wound to provide a horizontal magnetic deflection field; a vertical deflection means including a core around which a vertical deflection coil is wound to provide a vertical magnetic deflection field, the core surrounding the separator; a rear cover which fixes the deflection coil with the cathode ray tube, the rear cover is placed around the neck of cathode ray tube and has a first side oriented in the direction of the screen and resting against the rear end of the separator; and an arcuate bypass means positioned on the first side of the rear cover for correction of the incorrect convergence of the differential negative tap.

The diverting coil according to claim 24, wherein the arcuate shunt means comprises first and second "C" shaped shunts each of which has an internal radius which is parallel to the neck of the cathode ray tube .

26. The deflection coil according to claim 25, wherein each of the first and second "C" -shaped shunts are centered on a first axis of the neck of the cathode ray tube, the first axis being parallel with the shaft of the cathode ray tube screen.

27. The deflection coil according to claim 24, wherein the arcuate bypass means surrounds an angle of 120 ° around the neck of the cathode ray tube.

28. The deflection coil of claim 27, wherein each of the first and second "C" shaped shunts surround an angle of 120 ° around the neck of the cathode ray tube.

29. The deflection coil according to claim 24, wherein the arcuate bypass means is made of ceramic.

30. The biasing coil according to claim 29, wherein the permeability of the ceramic is 1000.

31. The biasing coil according to claim 24, wherein each of the arcuate branch means is made of rolled steel.

32. The diverting coil according to claim 25, wherein each of the first and second "C" shaped shunts is placed in a slot in the first side of the rear shroud.

33. The diverting coil according to claim 32, wherein each of the first and second taps is fixed in the slot as a synthetic resin and rubber rubber. SUMMARY OF THE INVENTION A device for correction of negative differential coma error in deflection coils free of convergence. The deflection coil encloses a portion of a cathode ray tube including a portion of the neck of the cathode ray tube and includes: a spacer around which a horizontal deflection coil is wound to provide a horizontal magnetic deflection field; a core around which a vertical deflection coil is wound to provide a vertical magnetic deflection field, the core partially surrounds the separator; and a back cover that secures the deflection coil to the cathode ray tube, the back cover is placed around the neck of the cathode ray tube and has a first side facing the direction of the cathode ray tube screen and resting against a rear end of the separator. According to the present invention, the arcuate branches that are preferably "C" shaped and have internal radii that are parallel to the neck of the cathode ray tube, are placed on the first side of the rear cover and are preferably centered in a first axis of the neck of the cathode ray tube and this axis is parallel to the axis of the cathode ray tube screen. The use of these derivations in the form of "C" is found to correct the negative differential coma error introduced by the deviation coil free of convergence.