JPS61292840A - Color picture tube device - Google Patents

Abstract

PURPOSE:To produce bright images of high resolution over the entire area of the screen with a minimal strain of the electron beam spot by making three electron beams discharged from an electron gun almost parallel to each other and producing both a horizontally deflecting magnetic field which is almost homogeneous and a vertically deflecting magnetic field which is vertically symmetrical relative to the axis of a color picture tube device. CONSTITUTION:When the vertically deflecting magnetic field is vertically nonsymmetrical as shown in Fig. (a), the electron beams are deflected upward. When it is vertically nonsymmetrical as shown in Fig. (b), the electron beams are deflected downward. The distance (D) between the axis of symmetry of the magnetic field and the axis of the electron beam increases as the intensity of the nonsymmetrical deflecting magnetic field increases. That is to say, the side electron beams receive outward force which is proportional to the intensity of the nonsymmetrical magnetic field, thereby increasing the distance between the deflecting electron beams at the end of the vertical axis. It is possible to make the beam axis at the enc of the vertical axis equal to that in the center of the screen by properly selecting the intensity of the nonsymmetrical magnetic field. This nonsymmetrical magnetic field can suppress the deflectional strain of the electron beam spot to a minimal level. Besides, it is possible to prevent color shift by producing a given delay of the signal applied to the electron gun.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION The present invention relates to improvements in in-line color picture tube devices.

[Technical background of the invention]

The envelope of the color picture tube has a neck that houses three electron guns,
It consists of a face plate with a fluorescent screen and a funnel interposed between the neck and the face plate.

3. The electron gun is installed horizontally in-line inside the neck, and the emitted electron beam hits a phosphor screen on which a phosphor layer is adhered, causing the phosphor layer to emit light. In order to make the phosphor layer emit light, it is necessary to selectively impinge the electron beam on a predetermined phosphor layer, so a shadow mask with a large number of apertures is placed close to the face plate. .

The in-line electron gun is designed to generate three electron beams in a common plane using a cathode and to concentrate these three electron beams near the face plate. 3. How to concentrate the electron beam.

For example, as shown in US Pat. No. 2,957,106, there is a technique in which the electron beam emitted from the cathode is tilted from the beginning, and US Pat. No. 3,772,554
As shown in the specification, by slightly deviating some of the holes on both sides of the electron beam out of the three electron beam passage holes provided in the electron gun electrode slightly outward from the central axis of the electron gun. There are technologies for concentrating electron beams, both of which are widely used.

In order to display a television image on the screen (phosphor screen) of a color picture tube, a deflection device is required to scan the electron beam emitted from the electron gun over the entire surface of the phosphor screen. Installed. The deflection device basically includes a horizontal deflection coil for generating a horizontal deflection magnetic field that deflects the electron beam in the horizontal direction and a vertical deflection coil for generating a vertical deflection magnetic field that deflects the electron beam in the vertical direction. ing. In an actual color picture tube device, when the electron beams are deflected, the concentration of the three electron beam spots on the face plate breaks down, so measures are taken to prevent this break in concentration. This is called a convergence free system, and the horizontal deflection magnetic field is made into a pincushion shape, and the vertical deflection magnetic field is made into a barrel shape, so that three electron beams are concentrated over the entire area of the phosphor screen. As a result, this system eliminates the need for a parabolic current generating circuit for convergence correction and a convergence yoke for generating a convergence correction magnetic field, resulting in many effects such as cost reduction and productivity improvement.

[Problems with background technology]

As mentioned above, the quality of color cathode ray tubes has been improved through the adoption of many developed technologies, but new problems are coming to the fore as the size of tubes becomes more widespread.

In other words, the beam spot emitted from the three electron guns and concentrated on the face plate presents only a circular core at the center of the screen where it is not subjected to deflection, but it forms a flattened core at the periphery of the screen where deflection is directed. and a flare that spreads upward and downward. As a result, the size of the electron beam increases at the periphery of the screen, causing deterioration in focus performance and resolution.

[Purpose of invention]

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide a color image receiving device that can obtain bright high resolution over the entire screen area with less distortion of the electron beam spot at the periphery of the screen. do.

[Summary of the invention]

The present invention has a neck in which three electron guns are installed horizontally in line, and the neck is connected to the neck through a funnel, and the inner surface of the neck is illuminated with three colors of red, green, and blue by the impact of the electron beams emitted from the electron guns. a face plate having a phosphor screen on which a light-emitting phosphor layer is regularly deposited; and a large number of apertures arranged close to the face plate to allow the electron beam to selectively impinge on the phosphor layer. In a color picture tube device having a shadow mask and a deflection device attached to the outer wall of the funnel and generating a horizontal deflection magnetic field that deflects the electron beam emitted from the electron gun in the horizontal direction and a vertical deflection magnetic field that deflects the electron beam in the vertical direction. , the three electron beams emitted from the electron gun are substantially parallel to each other, and the horizontal deflection magnetic field forms a substantially uniform magnetic field distribution.

[Embodiments of the invention]

The present invention will be explained below based on examples. FIG. 1 is a schematic cross-sectional view of a 20 inch 90 degree deflection color picture tube device of the present invention.

■ is the face plate, ■ is the funnel, and (a) is the neck, all of which are made of glass. On the inner surface of the face plate (2), phosphor dots or stripes that emit light in red (R), green (CG), and blue (B) are regularly arranged to form a fluorescent screen (2) for displaying images.

A shadow mask 0 is arranged close to and opposite to the phosphor screen (2). The shadow mask ■ usually consists of a thin steel plate with a dome shape similar to the inner surface of the face plate, and the part facing the phosphor screen ■ has many openings so that the electron beams can hit the phosphor correctly. It has holes.

Inside the neck) are 3 electron guns corresponding to 3 colors: red, green, and blue. These three electron guns are arranged in-line in the horizontal direction, and the emitted electron beams are approximately 6.6
They are constructed so that they are parallel to each other with an interval of (2). Each electron gun has a cathode control electrode, a blocking electrode, and a focusing electrode for the electron beam generation source.

It is composed of high-voltage electrodes, each of which is applied with a predetermined voltage.

The high voltage electrode voltage is normally an ultra-high voltage of Z5 kV, and the inside of the collar tube is maintained at an equal voltage of 25 kV.

The area near the neck connection part of the funnel ■ is called the cone part ■, and the deflection device ■ is usually attached to this part.

The deflection device includes a horizontal deflection magnetic field that generates a magnetic field that deflects the electron beam horizontally, and a vertical deflection magnetic field that generates a magnetic field that deflects the electron beam vertically.

The horizontal deflection magnetic field will be explained. FIG. 2 shows the magnetic field shape of the horizontal deflection coil of the present invention.

FIG. 3 shows the shape of the beam spot at the periphery of the screen, where (a) shows the beam spot shape of the present invention, and (b)
) is a conventional beam spot shape using a pincushion magnetic field shape.

In the present invention, it is due to a uniform magnetic field like 2v1.

The shape of the horizontally deflected electron beam spot is greatly improved.

Next, the vertical deflection magnetic field will be explained. Figure 4 shows an example of the vertically asymmetrical deflection magnetic field shape employed in the present invention, with (a) showing the situation when the electron beam is deflected upward, and (b) showing the situation when deflecting it downward. , and FIG. 5 shows the balance of currents energizing the toroidal coils above and below the deflection yoke, with the deflection direction and deflection amount corresponding to each other. Actually, the broken line shows the current that energizes the coil placed on the lower side, and the broken line shows the current that energizes the coil placed on the upper side.

In this asymmetrical deflection magnetic field, as the intensity of the deflection magnetic field increases, the distance between the magnetic field symmetry axis and the electron beam axis increases. That is, in the configuration of the present invention, the electron beams on both sides receive an outward force in proportion to the strength of the asymmetric magnetic field, which has the effect of widening the distance between the electron beams when deflected to the vertical axis end. By appropriately choosing the strength of the asymmetrical magnetic field, the beam spacing at the vertical axis end can be made the same as the spacing at the center of the screen.

This asymmetric magnetic field can minimize deflection distortion of the electron beam spot. That is, in the case of the asymmetric magnetic field shown in FIG. 4, the correction strength of the distance between both side beams is determined in proportion to the strength of the magnetic field. In other words, the relationship between beam interval correction and the amount of distortion of each beam at that time is proportional. On the other hand, with the conventional vertically symmetrical vertical deflection magnetic field, if each electron beam is not deflected or if it is only slightly deflected, the beam spacing cannot be corrected.

On the other hand, as is clear from the figure, the distortion itself of each beam naturally causes large distortion because the magnetic flux density differs depending on the position.

FIG. 6 schematically shows the beam shape on the screen of a color picture tube using the vertically asymmetric additional deflection magnetic field of the present invention. FIG. 7 shows the beam shape of a conventional color picture tube using the above-mentioned symmetrical deflection magnetic field. Shown schematically.

As can be seen from FIG. 6, in the color picture tube of the present invention, both side beams are more circular and the beam inclination is less.

This tendency can be seen throughout the entire screen.

In the color picture tube configured as described above, as shown in FIG. 8, the three color beams of red, green, and blue are spaced apart from each other by a certain amount Δ in the horizontal direction over the entire screen. If the image is displayed as is, the red (R), green (G), and blue (B) images will be displayed using the above-mentioned Δ
This will cause a color shift.

This color shift can be easily brought into alignment by adding a predetermined delay to the signal applied to the electron gun.

In other words, in conventional color picture tubes, when displaying white, R
, G, and B electron guns at the same time, in the color picture tube of the present invention, the G electron gun is delayed by a predetermined time τ, and the B electron gun is further delayed by 22. This delay time is determined by Δ τ "Co-terminal W-" (Fig. 9) where H is the width of the screen, fs is the horizontal deflection frequency,
C is a constant determined by overscan or the like.

〔Effect of the invention〕

The present invention achieves a screen in which the distortion of the electron beam spot is reduced over the entire screen by the above-described configuration and operation, and a bright, high-resolution color picture tube device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a color picture tube device of the present invention, and FIG.
The figure is a diagram explaining the shape of the horizontal deflection magnetic field of the deflection device according to the present invention, FIG. 3 is a diagram showing the shape of the electron beam spot,
FIG. 4 is a diagram explaining the shape of the vertical deflection magnetic field of the present invention, FIG. 5 is a diagram explaining the state of the current energized to the vertical deflection coil of the present invention, and FIGS. 6 and 7 are diagrams explaining the shape of the vertical deflection magnetic field of the present invention. FIG. 8 is a diagram for explaining the shape of the spot, FIG. 8 is a diagram for explaining the shift amount Δ of the three electron beams on the screen, and FIG. 9 is a diagram for explaining the delay time τ of the signal transferred to the three electron beams. 1...Face plate 2...Funnel 3...
・Neck 5... Fluorescent screen 6°°° Shadow mask 7... Electron gun agent Patent attorney Noriyuki Chika (and 1 other person) Figure 2 Figure 3 (a) (b) Figure 4 Figure 5

Claims (1)

[Claims] (1) A neck with 3 electron guns installed horizontally in-line, connected to this neck via a funnel, and created by the impact of the electron beams emitted from the electron guns on the inner surface, producing 3 colors of red, green, and blue. a face plate having a phosphor screen on which a light-emitting phosphor layer is regularly deposited; and a large number of apertures arranged close to the face plate to allow the electron beam to selectively impinge on the phosphor layer. In a color picture tube device having a shadow mask and a deflection device attached to the outer wall of the funnel and generating a horizontal deflection magnetic field that deflects the electron beam emitted from the electron gun in the horizontal direction and a vertical deflection magnetic field that deflects the electron beam in the vertical direction. , the three electron beams emitted from the electron gun are substantially parallel to each other, the horizontal deflection magnetic field forms a substantially uniform magnetic field distribution, and the vertical deflection magnetic field is formed from a vertically asymmetric deflection magnetic field with respect to the color picture tube axis. A color picture tube device characterized by: