JPH06283113A - Color picture tube device - Google Patents

Abstract

PURPOSE:To increase the sensitivity for electron beams and provide a good image by arranging a correction magnetic field collector for converged electron beams on an electron gun, and reinforcing the magnetic field generated by a velocity modulation coil. CONSTITUTION:A correction magnetic field collector 33 is arranged around electron beam passing holes of an electrode G5 where electron beams 30B, 30G, 30R pass in response to a velocity modulation coil 32 generating the magnetic field compensating the contour of a screen. The collector 33 is made of a magnetic substance, and the magnetic field generated by the coil 32 is collected by a magnetic field collection section 40 more widely. The collected magnetic flux can be concentratively applied to the electron beams 30B, 30G, 30R from magnetic field formation sections 38 arranged across electron beam passing holes 35 via connection sections 39. The contour of a screen can be satisfactorily corrected without increasing the magnetic field generated by the coil 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube which emits three electron beams arranged in a line passing through the same plane.
In particular, the present invention relates to a color picture tube device equipped with a velocity modulation coil.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 6, a color picture tube has an envelope composed of a panel 1 and a funnel-shaped funnel 2 integrally joined to the panel 1.
A phosphor screen 3 is formed on the inner surface of 1, and a shadow mask 4 having a large number of electron beam passage holes formed therein is arranged so as to face the phosphor screen 3. On the other hand, 3 electron beams 6 in the neck 5 of the funnel 2.
An electron gun 7 that emits B, 6G, and 6R is arranged. Then, the three electron beams 6B, 6G, which are emitted from this electron gun 7,
6R is deflected by the horizontal and vertical deflection magnetic fields generated by the deflection yoke 9 mounted on the outside of the boundary between the large-diameter portion 8 of the funnel 2 and the neck 5, and the phosphor screen 3 is horizontally and vertically scanned. Thus, a structure for displaying a color image is formed.

In such a color picture tube, a phosphor screen 3 is formed such that a plurality of vertically elongated black stripes are formed in parallel in the horizontal direction, and a three-color phosphor layer is embedded in the gap between the black stripes. Black stripe type phosphor screen, while electron gun 7
Center beam 6G and a pair of side beams 6B and 6R, which pass through the same horizontal plane, are arranged in a row in three electron beams 6B,
In-line color picture tubes, which are electron guns that emit 6G and 6R, are currently the mainstream of color picture tubes.

By the way, in such a color picture tube, there is a color picture tube apparatus in which a speed modulation coil 11 for defining the contour of an image is mounted above and below the neck 5 at the rear of the deflection yoke 9. Due to the space outside the neck, the velocity modulation coil 11 is usually attached to a cylindrical support 13 that supports the purity convergence magnet 12 as shown in FIG. An annular pair of purity adjusting magnets and two sets of convergence adjusting magnets forming the convergence magnet 12 are arranged so that they can be rotationally adjusted.

In FIG. 6, 14 is a funnel 2
Anode terminal 15 and electron gun 7 provided on the large-diameter portion 8 of
Is a drive circuit that applies a predetermined voltage to each electrode via the stem pin 16 and drives the deflection yoke 9 and the velocity modulation coil 11.

The operation of the velocity modulation coil 11 is shown in FIG.
The video signal 17 having a waveform whose horizontal axis is the time axis (t axis) in (a) is first-order differentiated to have peak values at the rising and falling parts of the video signal as shown in (b). This is performed by obtaining the pulse current 18 and supplying the pulse current 18 to the velocity modulation coil to generate a magnetic field. In this case, the magnetic field generated by the velocity modulation coil is combined with the horizontal deflection magnetic field generated by the deflection yoke to obtain the combined magnetic field 19 shown in (c). The second derivative of this synthetic magnetic field 19 is
It becomes a curve 20 shown in FIG.

The scanning speed of the horizontally deflected electron beam is
Proportional to changes in magnetic field. Therefore, the horizontal scanning speed of the electron beam changes as shown by the curve 20. That is, in the first half T1 period of the rising portion of the video signal (changed from black to white), the scanning speed is increased to reduce the image brightness, and in the latter half T2 period, the scanning speed is decreased to reduce the image brightness. Raise. In addition, the reverse occurs at the trailing edge (change from white to black) of the video signal, and the contours at the leading edge and trailing edge of the image are corrected to realize a screen with high sharpness.

Regarding a color picture tube device provided with such a velocity modulation coil 11, recently, the beam spot diameter on the phosphor screen 3 has increased due to the increase in size of the color picture tube, and the increase in the anode voltage due to higher brightness. With the flattening of the panel 1 and the like, the magnetic field for correcting the contour of the generated image tends to increase.

In this case, in order to increase the magnetic field for correcting the contour of the screen, the current flowing through the velocity modulation coil 11 may be increased, or the number of turns of the velocity modulation coil 11 may be increased. In order to increase the power consumption, not only the wire diameter of the coil needs to be increased, but also a large amount of current is passed, so that the power consumption increases, the load on the circuit side increases, and the cost increases. When the number of coil turns is increased, the velocity modulation coil 11 becomes thicker,
There is a problem that the adjusting action of the convergence magnet 12 is deteriorated. More generally, if the magnetic field for correcting the contour of the screen is increased by some method, not only the action of the magnetic field on the electron beam is increased, but also
The leakage magnetic field increases, which may cause the problem of electromagnetic interference.

[0010]

As described above, in order to clarify the contour of the image, there is a color picture tube device in which a velocity modulation coil is mounted on the outer side of the neck behind the deflection yoke. However, recently, color picture tubes have become larger, have higher definition,
The magnetic field generated by the velocity modulation coil tends to increase as the panel becomes flat.

In order to increase the magnetic field generated by the velocity modulation coil, the current flowing through the velocity modulation coil may be increased or the number of turns of the velocity modulation coil may be increased. In order to increase the current, Not only is it necessary to thicken the wire diameter of the coil, but also a large amount of current flows, which increases power consumption, increasing the burden on the circuit side and increasing costs. Further, when the number of turns of the coil is increased, the velocity modulation coil becomes thicker, and there is a problem that the adjusting action of the purity convergence magnet arranged outside the velocity modulation coil is reduced. More generally, if the magnetic field for correcting the contour of the screen is increased by some method, not only the action of the magnetic field on the electron beam is increased but also the leakage magnetic field is increased, which may cause a problem of electromagnetic interference. There is such a problem.

The present invention has been made in view of the above problems, and in a color picture tube device including a velocity modulation coil, increases the current flowing through the velocity modulation coil,
Another object is to construct a color picture tube device capable of displaying a good image by increasing the sensitivity to an electron beam without increasing the number of coils of the velocity modulation coil.

[0013]

An electron gun for focusing and emitting a row of three electron beams passing through the same plane is arranged in the neck, and a screen is provided outside the neck through which each focused electron beam passes. In a color picture tube device equipped with a velocity modulation coil that generates a magnetic field that compensates for the contour of the correction field, a correction magnetic field made of a magnetic material that strengthens the magnetic field generated by the velocity modulation coil with respect to the electron beam focused on the electron gun. Placed the collector.

[0014]

With the above arrangement, the correction magnetic field collector allows the magnetic field generated by the velocity modulation coil to be concentrated on the electron beam, so that the magnetic field generated by the velocity modulation coil is not increased and the contour of the screen is not increased. Can be satisfactorily corrected.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

FIG. 1 shows a color picture tube device as one embodiment of the invention. This color picture tube device has an envelope consisting of a panel 1 and a funnel-shaped funnel 2 integrally joined to the panel 1, and a plurality of vertically elongated black stripes are horizontally arranged on the inner surface of the panel 1. The phosphor screen 3 is formed in parallel with each other in the direction of the black stripe, and the stripe-shaped three-color phosphor layer that emits blue, green, and red is formed in the gap between the black stripes.
A shadow mask 4 having a large number of electron beam passage holes formed therein is disposed so as to face the above. On the other hand, in the neck 5 of the funnel 2, an in-line type electron gun 31 that emits three electron beams 30B, 30G, 30R arranged in a line consisting of a center beam 30G and a pair of side beams 30B, 30R passing on the same horizontal plane is arranged. Has been done. On the outside of the boundary between the large-diameter part 8 of the funnel 2 and the neck 5,
A deflection yoke 9 for generating a horizontal deflection magnetic field for deflecting the electron beams 30B, 30G, 30R in the horizontal direction (x-axis direction) and a vertical deflection magnetic field for deflecting the electron beams 30B, 30G, 30R in the vertical direction (y-axis direction) is mounted. Further, a velocity modulation coil 32 is attached above and below the neck 5 at the rear of the deflection yoke 9.

The electron gun 31 has three cathodes K arranged in a line in the horizontal direction which are separately heated by three heaters (not shown), and the phosphors 3 are sequentially arranged on the cathodes K in the direction of the phosphor screen 3. The first to fifth electrodes G1 to G5 arranged at a predetermined interval and the shield cup SC attached to the fifth electrode G5 thereof are provided, and the cathode K and this cathode
Three electron beams 30 emitted from the electron beam generator formed by the first and second electrodes G1 and G2 which are successively adjacent to K
B, 30G, 30R are formed in a structure in which they are focused on the phosphor screen 3 by the main lens portion formed by the third to fifth electrodes G3 to G5. The velocity modulation coil 32 is arranged outside the neck 5 corresponding to the fifth electrode G5 forming the main lens portion thereof.

Further, in this color picture tube device,
Corresponding to the velocity modulation coil 32, a correction magnetic field collector 33 that strengthens the magnetic field generated by the velocity modulation coil 32 is arranged in the fifth grid G5. That is, as shown in FIG. 2, the fifth electrode G5 forming the main lens portion is composed of a cup-shaped electrode, and the portion facing the fourth electrode corresponds to the three cathodes arranged in a line. Three electron beam passage holes 35 are formed in a line in the horizontal direction. Moreover, a burring 36 is provided around each electron beam passage hole 35 so as to form an electric field having a desired potential distribution with the fourth electrode. The correction magnetic field collector 33 is arranged inside the portion of the fifth electrode G5 facing the fourth electrode, and each electron beam passage hole 35
6 (three sets) of magnetic field forming portions 38 sandwiching the three burrings 36 around each of the burrings 36 from both sides in the vertical direction and three magnetic field forming portions 38 arranged on both sides of each burring 36 are connected. A magnetic field forming unit arranged on both sides of each burring 36, which is composed of a pair of connecting portions 39 and a pair of magnetic field collecting portions 40 arranged along the vertical inner wall of the cup-shaped electrode (fifth electrode G5).
38, the connecting part 39, and the magnetic field collecting part 40 are integrally connected to each other.

Each electrode of the electron gun is made of a paramagnetic material that allows a magnetic field to pass therethrough, but the correction magnetic field collector 33 is made of a magnetic material that acts on the magnetic field.

In FIG. 1, reference numeral 14 supplies a predetermined voltage to the anode terminal 15 provided in the large-diameter portion 8 of the funnel 2, each electrode of the electron gun 30, and the like, as well as the deflection yoke 9 and the velocity modulation coil 32. 42 is a drive circuit for driving the inner surface of the funnel 2, and the inner conductive film is applied from the inner surface of the large part 8 of the funnel 2 to the inner surface of the adjacent part of the neck 5, 43 is attached to the shadow mask 4, and the large part 8 of the funnel 2 is It is an inner magnetic shield located inside.

By the way, as described above, the velocity modulation coil 32
Corresponding to the electron beams 30B, 30G, 30R focused by the main lens formed by the third to fifth electrodes G3 to G5.
When the correction magnetic field collector 33 is arranged around the electron beam passage hole 35 of the fifth electrode G5 which passes through, as shown in FIG.
The magnetic field 45 generated by the velocity modulation coil is collected in a wide range by the magnetic field collection unit 40, and its magnetic flux is generated from the magnetic field formation unit 38 arranged across the electron beam passage hole 35 via the connection unit 39, each electron beam 30B, It is emitted to the passing region of 30G, 30R and can be made to act on each electron beam 30B, 30G, 30R intensively.

Specifically, the fifth electrode G5 of the electron gun 31 is formed of SUS304 having a plate thickness of 0.32 mm, and the correction magnetic field collector is formed.
33 is formed of permalloy with a plate thickness of 0.25 mm, and the fifth electrode
When attached to the outside of the G5 burring 36 by welding,
The sensitivity could be increased 1.8 times as compared with the case where the correction magnetic field collector 33 is not arranged.

In the above embodiment, the correction magnetic field collector has three sets of magnetic field forming portions which sandwich the three burrings formed around the electron beam passage hole 35 of the fifth electrode from the vertical direction, and on both sides thereof. It is configured by one set of connecting parts respectively connecting the three arranged magnetic field forming parts and one set of magnetic field collecting parts arranged along the vertical inner wall of the fifth electrode, as shown in FIG. As described above, the correction magnetic field collector 33 is
It is composed of only the magnetic field forming part 38, and this is composed of three burrings 36.
Even if they are arranged on both sides of, the magnetic field generated by the velocity modulation coil can be concentrated on each focused electron beam passing through the electron beam passage hole 35 of the fifth electrode G5. The effect is obtained.

Further, as shown in FIG. 5, the correction magnetic field collector 33 is formed by bending the correction magnetic field collector 33 into a key shape and a magnetic field collecting section 40.
Even if it is formed into a structure consisting of and, by the magnetic field collecting section 40, the magnetic field generated by the velocity modulation coil is adjusted, and the action on each focused electron beam passing through the electron beam passage hole 35 of the fifth electrode G5 is further enhanced. Can be good.

[0025]

According to the present invention, an electron gun for focusing and emitting one row of three electron beams passing through the same plane is arranged in the neck, and the contour of the screen is compensated outside the neck through which each focused electron beam passes. In a color cathode ray tube device in which a velocity modulation coil that generates a magnetic field is installed, a correction magnetic field collector made of a magnetic material that strengthens the magnetic field generated by the velocity modulation coil with respect to the electron beam focused on the electron gun is arranged. By the correction magnetic field collector, the magnetic field generated by the velocity modulation coil can be concentrated on the electron beam, and the contour of the screen can be favorably corrected without increasing the magnetic field generated by the velocity modulation coil. . Moreover, the load on the drive circuit due to the increase in power consumption is small, and the increase in leakage magnetic field can be avoided.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a color picture tube device that is an embodiment of the present invention.

FIG. 2 (a) is a plan view showing a configuration of a correction magnetic field collector arranged at a fifth electrode of an electron gun corresponding to the velocity modulation coil, and FIG. 2 (b) is a sectional view taken along line BB thereof. Is.

FIG. 3 is a diagram for explaining an action of the correction magnetic field collector.

FIG. 4 is a diagram showing another configuration of the correction magnetic field collector.

FIG. 5 shows another different configuration of the correction magnetic field collector.

FIG. 6 is a diagram showing a configuration of a conventional color picture tube device.

FIG. 7 is a diagram showing an arrangement of the velocity modulation coil.

FIG. 8A to FIG. 8D are diagrams for explaining the operation of the velocity modulation coil.

[Explanation of symbols]

 1… Panel 2… Funnel 3… Phosphor screen 4… Shadow mask 5… Neck 9… Deflection yoke 30B, 30R… Pair of side beams 30G… Center beam 31… Electron gun 32… Velocity modulation coil 33… Correction magnetic field collector 35… Electron beam passing hole 36 ... Burring 38 ... Magnetic field forming part 39 ... Connecting part 40 ... Magnetic field collecting part G1 ... First electrode G2 ... Second electrode G3 ... Third electrode G4 ... Fourth electrode G5 ... Fifth electrode K ... Cathode SC … Shield cup

Claims (1)

[Claims] 1. An electron gun for focusing and emitting one row of three electron beams passing through the same plane is arranged in the neck, and a contour of a screen is formed on the outside of the neck through which each of the focused electron beams passes. In a color picture tube device equipped with a velocity modulation coil for generating a compensating magnetic field, a correction magnetic field made of a magnetic material for strengthening the magnetic field generated by the velocity modulation coil with respect to the electron beam focused on the electron gun. A color picture tube device characterized in that a collector is arranged.