JP2004304519A - In-line color cathode ray tube apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-line color cathode ray tube apparatus in which the convergence characteristic is improved by suppressing the repulsion between the electron beams while a conventional in-line self-convergence color cathode ray tube apparatus has adopted ununiform deflection magnetic field so as to eliminate the need for a dynamic convergence circuit and the repulsion takes place between the three electron beams on the occurrence of a high luminance beam current in the case of a bright screen or the like thereby producing a convergence error by both side beams. <P>SOLUTION: When the beam current increases, a beam current response circuit 32 detects the increase in the beam current, a correction current based on the detection is supplied to the side beam correction yokes 22, 22' located at an outer circumference of the neck 12 opposite to both side beams 17B, 17R so as to correct the side beams 17B, 17R in the direction of the center beam 17G. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a color cathode ray tube device used for a color television receiver, a color terminal display, and the like, and more particularly to an in-line type color cathode ray tube device for improving convergence error of both side beams at high luminance.
[0002]
[Prior art]
In general, as shown in FIG. 5, an in-line type color cathode ray tube device has a face panel 61 having a substantially rectangular display portion, a funnel-shaped funnel 62 connected to the face panel 61, and a diameter of the funnel 62. It has a glass envelope 64 composed of a cylindrical neck 63 connected to the small part.
[0003]
On the inner surface of the face panel 61, a phosphor screen 65 having a striped three-color phosphor layer that emits red, blue, and green light is provided. One center beam 66G, and a row of electron beams 66B, 66G, 66R in which a pair of side beams 66R, 66B are positioned on both sides thereof pass, and a shadow mask 67 for performing color selection is provided on the inner surface of the face panel 61. An in-line type electron gun 69 which is attached via a frame 68 and emits three electron beams 66B, 66G, 66R is disposed in a neck 63, thereby forming an in-line type color cathode ray tube 70.
[0004]
The electron beams 66B, 66G, and 66R are deflected by the magnetic field of the deflection yoke 71 mounted on the outer periphery of the envelope 64 extending from the neck 63 to the small diameter portion of the funnel 62, and the electron beams 66B, 66G, and 66R are deflected. By scanning the phosphor screen 65 in the horizontal and vertical directions, a color image is displayed on the phosphor screen 65.
[0005]
Further, a purity convergence magnet (PCM) 72 composed of a purity magnet and a static convergence magnet is provided on the outer peripheral surface of the neck 63. The PCM 72 is composed of a pair of plate-shaped and annular magnets, and the magnets are relatively rotated to change the magnetic force on the electron beams 66B, 66G, and 66R, and the electron beams 66B, 66G, and 66R. Orbits are adjusted.
[0006]
In such a color cathode ray tube device, an in-line self-convergence type color cathode ray tube device which does not require any circuit convergence correction is currently the mainstream. In this in-line self-convergence type color cathode ray tube device, an in-line type which emits three electron beams 66R, 66G, 66B in a line composed of a center beam 66G and a pair of side beams 66R, 66B passing through an electron gun 69 on the same horizontal plane. A color cathode ray tube 70 configured as an electron gun 69 and a deflection yoke 71 used in combination with the color cathode ray tube 70 are horizontally deflected so that the horizontal deflection magnetic field becomes a pincushion type and the vertical deflection magnetic field becomes a barrel type. By winding the coil and the vertical deflection coil to form a non-uniform magnetic field, the magnetic field distribution of the deflection yoke 71 and the PCM 72 are adjusted, so that no special dynamic correction means is required, and the entire phosphor screen 65 is not required. Convergence characteristics over a wide range.
[0007]
[Problems to be solved by the invention]
Although a sufficient image quality can be obtained even in such a color cathode ray tube device, in a flat panel type color cathode ray tube device in which the screen is flattened, a better convergence quality has been required. I have. One of the problems is a change in convergence when the beam current is low and when the beam current is high. This variation in convergence is caused by the repulsion of the three electron beams 66B, 66G, and 66R, which are arranged in a row in parallel, when the current is high, and causes a repulsion between the electron beams 66B, 66G, and 66R. , 66G, and 66R are caused to work away from each other.
[0008]
In particular, when the amount of electron beam when the screen becomes bright, in other words, when the electron beam current becomes large, as shown in FIG. Therefore, the convergence is shifted to the right and the blue is shifted to the left in the entire screen at the time of high luminance, thereby deteriorating the convergence.
[0009]
For example, it was found that when the beam current was changed from 100 μA to 1,000 μA using the crosshatch signal to change to a large beam current state, the convergence of red and blue fluctuated by about 0.40 mm. This large beam current is generated when the screen is in a bright state, that is, in a white screen state. In this state, between the one side beam 66B and the center beam 66G, and the other side beam 66R And the center beam 66G is caused by a repulsive action. At this time, the position of the center beam 66G remains unchanged because the repulsion from the side beams 66B and 66R is canceled out, and only the side beams 66B and 66R are affected by this. In particular, the red side beam 66R moves rightward and the blue side beam 66B moves leftward, deteriorating convergence.
[0010]
The present invention has been made to address such a problem, and generates a quadrupole magnetic field for correction acting in the direction opposite to the direction of repulsion of both side beams in accordance with an increase in beam current. Accordingly, it is an object of the present invention to provide an in-line type color cathode ray tube device capable of obtaining good convergence characteristics by suppressing the repulsive force of both side beams.
[0011]
[Means for Solving the Problems]
The present invention provides a substantially rectangular face panel having a phosphor screen having a three-color phosphor layer disposed on an inner surface thereof, a funnel-shaped funnel connected to the face panel, and a deflection device mounted on an outer peripheral portion of the funnel. A yoke, an in-line type electron gun which emits a center beam and a pair of side beams deflected in the horizontal and vertical directions by the deflection yoke and is disposed in a neck facing the phosphor screen via a shadow mask; A side beam correction yoke arranged on the neck outer periphery to correct the pair of side beams in the center beam direction by a correction current responding to the fluctuation of the beam current, and when the beam current amount is increased by the side beam correction yoke, The side beam is corrected so as to approach the center beam.
[0012]
With this configuration, it is possible to suppress the fluctuation of the electron beam due to the repulsion between the three electron beams at the time of high luminance, to correct the convergence error due to both side beams, and to improve the convergence quality. Can be.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0014]
FIG. 1 shows a configuration of an in-line type color cathode ray tube apparatus according to the present invention in which a deflection yoke and a side beam correction yoke are mounted on a color cathode ray tube. The color cathode ray tube has a substantially rectangular face panel 10 having a substantially flat outer surface having a horizontal axis (H axis) and a vertical axis (V axis) passing through a tube axis (Z axis) and orthogonal to each other. And a vacuum envelope 13 composed of a cylindrical neck 12 connected to the end of the small diameter portion of the funnel 11.
[0015]
On the inner surface of the face panel 10, a phosphor screen 14 having a striped three-color phosphor layer that emits blue, green, and red light is provided. Further, the phosphor screen 14 is separated from and opposed to the phosphor screen 14. A shadow mask 15 in which a large number of electron beam passage holes are formed at a predetermined arrangement pitch on the opposing surface is arranged. The shadow mask 15 is fixed to a mask frame 16 and locked in a vacuum envelope 13. .
[0016]
In the neck 12, an in-line type electron gun 18 that emits three electron beams 17B, 17G, 17R arranged in a line composed of a center beam 17G and a pair of side beams 17B, 17R passing on the same horizontal plane is arranged. A color cathode ray tube 19 is configured. The deflection yoke 20 is mounted from the funnel 11 side of the neck 12 to the small diameter portion of the funnel 11. A purity convergence magnet (PCM) 21 is provided outside the neck 12 behind the deflection yoke 20.
[0017]
Further, at the rear end of the deflection yoke 20, as shown in FIG. 2, a pair of side beam correction yokes 22 and 22 'facing each other so as to face both side beams 17B and 17R so as to extend along the neck 12. Are located.
[0018]
The deflection yoke 20 has a coil separator 23 formed of a funnel-shaped synthetic resin. A saddle-type horizontal deflection coil (not shown) is mounted inside the coil separator 23, and is mounted outside the coil separator 23. A vertical deflection coil 24 formed in a saddle shape is mounted, and a conical core 25 is mounted outside the vertical deflection coil 24. The vertical deflection coil 24 may be configured as a toroidal type in which a core 25 is wound. At the upper and lower ends of the vertical deflection coil 24, a pair of rod-shaped permanent magnets 26 for pincushion distortion correction are fixedly arranged on the back surface of the coil separator 23 on the large diameter side.
[0019]
On the other hand, a pair of side beam correction yokes 22 and 22 ′ facing each other with the neck 12 interposed therebetween are mounted on the small-diameter portion side end surface 27 of the coil separator 23. The side beam correcting yokes 22 and 22 ′ are each composed of a U-shaped core 28, 28 ′ and coils 29, 29 ′ wound around the central portions of the cores 28, 28 ′. It is arranged to face a pair of passing side beams 17B and 17R, and generates a quadrupole magnetic field for correcting the side beams 17B and 17R so as to approach the center beam 17G, respectively.
[0020]
The side beam correction yokes 22 and 22 'are driven by a beam current response circuit 32 for extracting a correction current corresponding to a beam current from a cathode circuit 30 or a high voltage circuit 31 for driving the color cathode ray tube 19, and the like. When the beam current amount of the beams 17B, 17G, and 17R increases, in other words, the beam current when the screen becomes brighter is detected, and both side beams 17B and 17R are changed to the center beam according to the fluctuation of the beam current. The function of correcting in the 17G direction is used to make convergence optimal.
[0021]
The beam current response circuit 32 is configured, for example, as shown in FIG.
[0022]
That is, the secondary side of the flyback transformer 34 connected to the horizontal output circuit 33 is connected to the high voltage circuit 31 that supplies an anode voltage to the anode of the color cathode ray tube 19. In the high-voltage circuit 31, the power supply + B1 is connected to the low-voltage side end of the secondary winding 35 of the flyback transformer 34 via the resistor 36, the high-voltage rectifier diode 37 is connected to the high-voltage side, and the high-voltage circuit 31 Rectifying the flyback pulse to supply a high voltage to the anode. The connection point of the resistor 36 with the secondary winding 35 is grounded via a parallel circuit of a capacitor 38 and a resistor 39, and connected to the emitter of a PNP transistor 41 via a resistor 40. The base of the transistor 41 is grounded, and the collector is connected to the power supply + B2 via the resistor. A switching diode 43 having a cathode connected to the collector is connected to the collector. The cathode of the diode 43 is connected to the coil 29 of the one side beam correction yoke 22. This coil 29 is connected in series with the coil 29 'of the other side beam correction yoke 22', and the other end of the coil 29 'is grounded via a power supply VE.
[0023]
The side beam correction yokes 22 and 22 'are provided with magnetic poles formed by coils 29 and 29' at the center of U-shaped cores 28 and 28 'arranged to face both side beams 17B and 17R. It is wound so that the polarities are inverted at the positions of the beams 17B and 17R, and gives a function of causing the pair of side beams 17B and 17R to approach in the direction of the center beam 17G when energized.
[0024]
With this configuration, the anode current flows from the power supply + B1 to the anode of the color cathode ray tube 19 via the resistor 36, the secondary winding 35, and the diode 37, and the anode current is Fluctuates in proportion to the beam current. Now, when the screen of the color cathode ray tube 19 becomes bright and the beam current increases, the anode current also increases in proportion to this, and the voltage drop of the resistor 36 increases accordingly. Is reduced. With the decrease in the potential, the emitter of the transistor 41 is biased in the forward direction, so that the transistor 41 conducts, and a current flows through the transistor 41 to reduce the collector potential. Due to this decrease in the collector potential, the diode 43 becomes conductive, and a correction current flows from the power supply VE via the coils 29 ', 29 to generate magnetic flux in the coils 29, 29'.
[0025]
This magnetic flux generates a magnetic field that shifts the side beam 17B toward the center beam 17G with respect to one side beam 17B, and generates the side beam 17R with respect to the other side beam 17R. The winding directions and connection positions of the coils 29 and 29 'are set so as to generate magnetic fields in opposite directions to the pair of side beams 17B and 17R, respectively, so as to shift in the direction of the center beam 17G.
[0026]
Therefore, a quadrupole magnetic field is generated so as to correct the strong repulsion between the electron beams 17B, 17G, and 17R caused by the increase in the amount of the electron beam when the screen becomes bright. By correcting the direction in which the repulsive force between 17G and 17R is eliminated, the convergence fluctuation can be corrected, and a good convergence state can be set.
[0027]
In this manner, the variation of the anode current which varies in proportion to the beam current is detected, and the side beam correction yokes 22, 22 'are driven by the beam current response circuit 32 which responds to the variation of the beam current. Convergence can be obtained, and the screen quality can be improved.
[0028]
Further, the detection of the fluctuation of the beam current can be performed by detecting the fluctuation of the cathode current as well as the fluctuation of the anode current.
[0029]
That is, as shown in FIG. 4, a video output circuit 44 is connected to a cathode electrode K of the color cathode ray tube 19, and resistors 45, 46, and 47 are connected to the cathode electrode K, respectively. Is connected to a power supply + B3 via a resistor 48, and a predetermined bias voltage is supplied to the cathode electrode K. A switching diode 49 is connected to the connection point between the resistor 48 and each of the resistors 45 to 47 such that the anode side is the connection point side, and a parallel connection of a capacitor 50 and a resistor 51 is provided on the cathode side of the diode 49. The circuit is connected, and further connected to the base of the PNP transistor 52. The collector of the transistor 52 is connected to a power supply + B4 via a resistor 53, and the power supply + B4 is also connected to the base of the transistor 52 via a resistor 54.
[0030]
On the other hand, the emitter of the transistor 52 is grounded via a parallel circuit of a resistor 55 and a capacitor 56, and is connected to one end of the coil 29 of one side beam correction yoke 22. The other end of the coil 29 is connected in series with the coil 29 'of the other side beam correction yoke 22', and the other end of the coil 29 'is configured to be grounded.
[0031]
Now, assuming that the screen of the color cathode ray tube 19 becomes bright and the beam current increases, the cathode current also increases and flows through the resistors 45 to 47 and the resistor 48. At this time, a voltage drop occurs at both ends of the resistor 48, and the potential at the connection point between the resistors 45 to 47 and the resistor 48 rises. As a result, the diode 49 conducts, the base potential of the transistor 52 rises, and the transistor 52 conducts. When the transistor 52 is turned on, a correction current flows from the power supply + B4 through the collector-emitter path, and the correction current also flows into the side beam correction yokes 22, 22 'to generate a quadrupole magnetic field.
[0032]
This magnetic field generates a magnetic field that shifts one side beam 17B in the direction of the center beam 17G and also shifts the other side beam 17R in the direction of the center beam 17G. The quadrupole magnetic field generates both side beams 17B, 17R. Is corrected so as to move the electron beam in the direction of the center beam 17G, and acts in a direction to cancel the repulsion between the electron beams 17B, 17G, and 17R due to the increase in the beam current, thereby suppressing the convergence fluctuation. This makes it possible to improve image quality.
[0033]
Since this cathode current also fluctuates in accordance with the increase and decrease of the beam current amount, the fluctuation can be detected by the beam current response circuit 32, and the correction current can be supplied to the side beam correction yokes 22, 22 '. Compared to the case of detecting the variation of the anode current described above, since the detection can be performed in the low-voltage circuit portion, it is possible to configure the low-voltage circuit components having a low withstand voltage rating, and to configure the device at lower cost. be able to.
[0034]
In the above description, the case of the color difference system in which the video output circuit 44 is connected to the cathode electrode K is described. However, the present invention can also be applied to the case of the primary color system in which a primary color signal is applied to the cathode electrode K. Furthermore, it is also possible to adopt a configuration other than the configuration in which the coils 29, 29 'are wound around the center of the U-shaped cores 28, 28' for the side beam correction yokes 22, 22 '. It is also possible to wind the split coils 29, 29 'around both leg portions of the cores 28, 28', respectively. In addition to attaching to the end surface 27, it is also possible to attach to the PCM 21 or independently attach to the outer peripheral surface of the neck 12.
[0035]
【The invention's effect】
In the in-line type color cathode ray tube device according to the present invention, the repulsion between the center beam and both side beams is moved in the direction of the center beam in response to the increase in the amount of beam current when the screen becomes bright. By adding a side beam correction yoke to make the convergence error effective, convergence characteristics can be improved even in a high luminance state, and the image quality can be improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an in-line type color cathode ray tube device according to the present invention.
FIG. 2 is a perspective view showing a deflection yoke and a side beam correction yoke constituting the in-line type color cathode ray tube device according to the present invention.
FIG. 3 is a circuit diagram showing one form of a beam current response circuit that also forms the in-line type color cathode ray tube device.
FIG. 4 is a circuit diagram showing another circuit configuration of the beam current response circuit.
FIG. 5 is a configuration diagram showing a conventional in-line type color cathode ray tube device.
FIG. 6 is an explanatory diagram for explaining a state of each electron beam in a high brightness state of the conventional in-line type color cathode ray tube.
[Explanation of symbols]
10: face panel 11: funnel 12: neck 14: phosphor screen 15: shadow mask 17G: center beam 17R, 17B: side beam 18: electron gun 20: deflection yoke 22, 22 ': side beam correction yoke 32: beam current Response circuit

Claims (2)

A substantially rectangular face panel having a phosphor screen having a three-color phosphor layer disposed on an inner surface thereof;
A funnel-shaped funnel connected to this face panel,
A deflection yoke mounted on the outer periphery of the funnel;
The deflection yoke emits a center beam and a pair of side beams deflected in the horizontal and vertical directions, and an in-line type electron gun disposed in a neck facing the phosphor screen through a shadow mask,
A side beam correction yoke arranged on the outer periphery of the neck to correct the pair of side beams in the center beam direction by a correction current responsive to a change in beam current;
An in-line type color cathode ray tube device, wherein the side beam correction yoke corrects both side beams so as to approach the center beam direction when a beam current amount increases. 2. The in-line type color cathode ray tube device according to claim 1, wherein the correction current responding to the fluctuation of the beam current is changed in response to the fluctuation of the cathode current.

Images