JP3923983B2 - Cathode ray tube equipment - Google Patents

Description

  The present invention relates to a cathode ray tube apparatus.

  In recent years, demands for flattening and increasing the size of the display screen of a cathode ray tube apparatus have increased. In order to satisfy this requirement while ensuring a certain mechanical strength, it is necessary to increase the thickness of the glass bulb for a cathode ray tube, resulting in an increase in weight.

Patent Document 1 describes a glass funnel for a cathode ray tube that can simultaneously realize sufficient strength and weight reduction that can withstand vacuum breakage. In this funnel, a step is formed on the outer surface in the vicinity of the junction with the front panel of the funnel so that the thickness is thick at the junction with the front panel and becomes thinner in the region closer to the neck.
JP 2002-237266 A

  In general, in a cathode ray tube apparatus, an electron beam is deflected so that the electron beam scans (overscans) a region larger than the screen display region. When the electron beam collides with the inner wall surface of the funnel when this overscan is performed, the electron beam reflected here enters the phosphor screen and emits the phosphor, so-called cone halation occurs. This results in image quality degradation. The collision between the electron beam and the inner wall surface of the funnel is likely to occur in the vicinity of the funnel region facing the deflection yoke.

  In order to prevent cone halation, the inner dimensions of the funnel may be increased so that the electron beam does not collide with the inner wall surface of the funnel even if overscanning occurs.

  However, in the above-described conventional funnel in which the thickness is reduced in the region closer to the neck portion than the step, in order to increase the inner dimensions of the funnel, it is necessary to further reduce the thickness of the funnel. In the funnel, it is required to use lead-containing glass and secure a certain thickness in order to suppress the amount of X-ray leakage to a predetermined value or less. Therefore, if the thickness of the funnel is reduced, a new problem of increasing the amount of X-ray leakage occurs.

  In order to enlarge the inner dimension of the funnel while ensuring a certain thickness, it is necessary to increase the outer dimension of the funnel. However, the outer dimension of the funnel has an upper limit in order to avoid interference with the deflection yoke mounted on the outer peripheral surface of the funnel. If the inner dimension of the deflection yoke is increased in order to increase the outer dimension of the funnel, the distance between the deflection yoke and the electron beam increases, leading to an increase in deflection power.

  An object of the present invention is to solve the above-described conventional problems, and to provide a cathode ray tube apparatus capable of preventing cone halation while suppressing the amount of X-ray leakage to a predetermined value or less.

The cathode ray tube device according to the present invention includes a front panel having a phosphor screen formed on the inner surface, a funnel joined to the front panel, an electron gun housed in a neck portion of the funnel, and an outer peripheral surface of the funnel. And a deflection yoke including a horizontal deflection coil for deflecting the electron beam emitted from the electron gun in the horizontal direction and a vertical deflection coil for deflecting in the vertical direction. Then, in the cross section including the tube axis, the thickness of the funnel at the first point on the outer surface of the funnel whose position in the tube axis direction is the same as the end of the horizontal deflection coil on the phosphor screen side is T1. The position of 7 mm on the phosphor screen side along the tube axis from the phosphor screen side end of the horizontal deflection coil is the same as the position in the tube axis direction at a second point on the outer surface of the funnel. When the thickness of the funnel is T2, the funnel has an increase in the outer dimension of the funnel at the second point with respect to the first point at the second point with respect to the first point. At least one cross section including a tube axis that is larger than the increase in the inner dimension of the funnel and satisfies T2 / T1 ≧ 1.18 is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the cathode ray tube apparatus which can prevent cone halation can be implement | achieved, suppressing X-ray leakage amount below a predetermined value.

  FIG. 1 is a configuration diagram of a cathode ray tube apparatus according to an embodiment of the present invention. In the figure, the Z axis means the tube axis of the cathode ray tube.

  The cathode ray tube (CRT) includes an envelope including a front panel 2 and a funnel 3, and an electron gun 4 provided in a neck portion 3 a of the funnel 3. The cathode ray tube device 1 includes the cathode ray tube and a deflection yoke 10 attached to the outer peripheral surface of the funnel 3. On the inner surface of the front panel 2 is formed a phosphor screen 2a in which phosphor dots (or phosphor stripes) of blue (B), green (G), and red (R) are arranged. A shadow mask 5 is attached to the inner wall surface of the front panel 2 so as to face the phosphor screen 2a. The shadow mask 5 is made of a metal flat plate in which a large number of substantially slot-shaped openings, which are electron beam passage holes, are formed by etching, and three electron beams 7 emitted from the electron gun 4 (shown as one in FIG. 1). ) Passes through the aperture and strikes a predetermined phosphor dot.

  The deflection yoke 10 deflects the three electron beams 7 emitted from the electron gun 4 in the horizontal direction and the vertical direction, and scans the phosphor screen 2a. The deflection yoke 10 includes a saddle type horizontal deflection coil 11, a saddle type vertical deflection coil 12, and a ferrite core 14. An insulating frame 13 made of an insulating material (for example, resin) is provided between the horizontal deflection coil 11 and the vertical deflection coil 12. The insulating frame 13 holds the horizontal deflection coil 11 and plays a role of maintaining an electrical insulation state between the horizontal deflection coil 11 and the vertical deflection coil 12 arranged outside the horizontal deflection coil 11.

  FIG. 2 shows a half sectional view along the Z-axis of the envelope composed of the front panel 2 and the funnel 3. Since the cross-sectional shape of the envelope is symmetrical with respect to the Z-axis, FIG. 2 is shown as a single cross-sectional view. A horizontal deflection coil 11 of the deflection yoke 10 is also shown by a two-dot chain line.

  In the present invention, funnel thicknesses T1 and T2 at two points P1 and P2 on the outer surface of the funnel 3 are defined in the cross section including the Z-axis. The first point P1 refers to a point on the outer surface of the funnel 3 where the horizontal deflection coil 11 has the same position in the Z-axis direction as the end 11a on the phosphor screen 2a side. The second point P2 is the outer surface of the funnel 3 whose position in the Z-axis direction is the same as the position of 7 mm on the phosphor screen 2a side along the Z-axis from the end 11a of the horizontal deflection coil 11 on the phosphor screen 2a. Say the top point. The thicknesses T1 and T2 of the funnel 3 at the first and second points P1 and P2 are the thicknesses of the funnel 3 along the normal to the outer surface of the funnel 3 at the points P1 and P2. The funnel 32 of the present invention has at least one cross section including the Z-axis in which the thicknesses T1 and T2 defined as described above satisfy T2 / T1 ≧ 1.18. That is, T2 / T1 ≧ 1 in at least one of a vertical cross section including the Z axis, a horizontal cross section including the Z axis, a diagonal cross section of the screen including the Z axis, or a cross section including the other Z axes. .18 is satisfied.

  The operation of the funnel 3 having such a cross-sectional shape will be described with reference to examples.

  In the cross section including the Z axis along the diagonal direction of the display screen, the thicknesses T1 and T2 defined as described above are used in three different funnels 3 as shown in Table 1, and the diagonal size is 28. A wide-type color cathode ray tube device having an inch and display screen aspect ratio of 16: 9 was produced (Examples 1, 2, and 3, Comparative Examples 1 and 2).

  Regarding the funnel 3 of Example 1 and Comparative Example 1, the thickness change along the Z axis in a cross section including the Z axis along the diagonal direction of the display screen is shown in FIG. In FIG. 3, the horizontal axis indicates the position on the Z-axis with the position of the reference line (RL) as the origin and the phosphor screen 2a side as positive. Here, the reference line is a virtual reference line perpendicular to the Z axis, and the position on the Z axis coincides with the geometric deflection center position of the cathode ray tube. In Examples 1, 2, and 3 and Comparative Examples 1 and 2, the position of the horizontal deflection coil 11 on the phosphor screen 2a side end 11a on the Z-axis was 28 mm. Therefore, the positions on the Z-axis of the first point P1 and the second point P2 were 28 mm and 35 mm in order.

  As shown in FIG. 3, the thickness of each funnel 3 of Example 1 and Comparative Example 1 is horizontal deflection from the reference line RL toward the positive direction of the Z axis along the Z axis. The region where the coil 11 is present (Z ≦ 28 mm) is relatively thin, and increases as it approaches the phosphor screen 2a side beyond the first point P1. However, compared with the comparative example 1, in Example 1, it is thick in the area | region of Z = 30-50 mm. As shown in FIG. 2, this increase in thickness in the first embodiment is realized mainly by increasing the increase amount of the outer dimension of the funnel 3 compared to the increase amount of the inner dimension.

  With respect to the color cathode ray tube apparatuses of Examples 1, 2, and 3 and Comparative Examples 1 and 2, cone halation luminance and X-ray leakage were measured.

The cone halation luminance measurement is displayed when the electron beam collides with the inner surface of the funnel and is reflected after reaching the phosphor screen when the electron beam is 110% overscanned vertically and horizontally with respect to the display screen. This was done by measuring the brightness of the screen. In Examples 1, 2, and 3 and Comparative Examples 1 and 2, the relative positions of funnel 3 and deflection yoke 10 were adjusted so that the cone halation luminance was 0.15 (cd / mm ² ). The value of the cone halation luminance of 0.15 (cd / mm ² ) is an upper limit value for preventing the cone halation from being visually recognized by the naked eye.

  The amount of X-ray leakage is the outer surface of the virtual cabinet defined by EIAJ ED-2112A when a voltage of 40 kV is applied to the anode and the electron beam is overscanned in the vertical and horizontal directions by 110%. Is the maximum value of the X-ray intensity measured around the Z-axis while maintaining a distance of 50 mm.

  These measurement results are also shown in Table 1.

  In Examples 1, 2, and 3 where the thickness of the funnel 3 satisfies T2 / T1 ≧ 1.18, the amount of X-ray leakage is smaller than that in Comparative Examples 1 and 2. This is due to the following reason.

  The glass material constituting the funnel 3 contains lead. The thicker the glass material, the lower the X-ray transmittance. X-ray leakage from the cathode ray tube device is likely to occur at and near the location where the electron beam collides with the funnel 3. The electron beam collides with the funnel 3 mainly in a region between the reference line RL and a point further away from the phosphor screen side by a predetermined distance (in this embodiment, approximately Z = 0 to 50 mm). Area).

  In this region, in the region where the deflection yoke 10 is opposed (in this embodiment, the region where Z = 0 to 28 mm), even if the X-ray leaks, the deflection yoke 10 absorbs the X-ray, and thus the cathode ray. The amount of X-ray leakage out of the tube device is small. Therefore, in the present invention, the thickness of the funnel 3 is reduced in this region, thereby preventing the electron beam from colliding with the funnel 3 without increasing the internal dimension of the deflection yoke 10. As a result, the occurrence of cone halation can be prevented without increasing the deflection power and without increasing the amount of X-ray leakage.

  Further, in the present invention, the thickness of the funnel 3 in the region of the funnel 3 where the electron beam may collide, in the region where the deflection yoke 10 does not face (in the present embodiment, the region of approximately Z = 28 to 50 mm). Therefore, the amount of X-ray leakage can be reduced. In addition, the increase in thickness in this region is realized mainly by enlarging the outer dimensions of the funnel 3, so that it is possible to prevent the electron beam from colliding with the funnel 3, thereby preventing the occurrence of cone halation. Can be suppressed.

  Thus, according to the present invention, it is possible to realize a cathode ray tube apparatus capable of preventing cone halation while suppressing the X-ray leakage amount to a predetermined value or less.

  In the first to third embodiments, the case where T2 / T1 ≧ 1.18 is satisfied in the cross section including the Z axis along the diagonal direction is described. However, the present invention is not limited to this, and for example, the vertical direction , T2 / T1 ≧ 1.18 may be satisfied in a cross section including the Z axis along the horizontal direction or other directions. However, it is preferable that T2 / T1 ≧ 1.18 is satisfied in the cross section having the smallest thickness T1 in the cross section group including the Z axis. Depending on the funnel, the thickness T1 of the funnel 3 at the first point P1 defined in each cross section including the Z axis may vary depending on the direction of the cross section around the Z axis. In general, the thickness T1 is often reduced in order to avoid collision of the electron beam in the vicinity of the portion. Therefore, among the multiple cross-sectional groups including cross-sections in various directions including the Z-axis, T2 / T1 ≧ 1.18 is satisfied in the cross-section where the thickness T1 is the minimum, so that the deflection power is not increased. In addition, it is easy to rationally design a funnel that can prevent the occurrence of cone halation without increasing the amount of X-ray leakage.

  In the above-described embodiment and examples, the thickness of the funnel 3 is changed by forming a step on the outer surface of the funnel 3 so that the second point P2 protrudes from the first point P1. However, from the viewpoint of the manufacturing process of the funnel 3, it is preferable that the thickness of the funnel 3 changes uniformly or smoothly in the Z-axis direction. Accordingly, it is preferable that local irregularities are formed on the inner surface and / or outer surface of the funnel 3 so that the thickness of the funnel 3 is drastically reduced on the phosphor screen 2a side than the second point P2. Absent.

  In the above embodiments and examples, the color cathode ray tube apparatus has been described as an example. However, the present invention can also be applied to a monochrome display cathode ray tube apparatus.

  In the above-described embodiment, the case where the vertical deflection coil 12 is a saddle type is illustrated, but a toroidal vertical deflection coil can also be used.

  The field of application of the cathode ray tube device of the present invention is not particularly limited. For example, it can be widely used for a television or a computer display.

It is sectional drawing which showed schematic structure of the cathode ray tube apparatus which concerns on one Embodiment of this invention. In the cathode ray tube apparatus which concerns on one Embodiment of this invention, it is a half sectional view of the envelope which consists of a front panel and a funnel. It is the figure which showed the thickness change along the Z-axis of the funnel in the cross section containing the Z-axis along the diagonal direction of a display screen about the funnel of Example 1 and the comparative example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cathode ray tube apparatus 2 Front panel 2a Phosphor screen 3 Funnel 3a Neck part 4 Electron gun 5 Shadow mask 7 Electron beam 10 Deflection yoke 11 Horizontal deflection coil 11a Phosphor screen side end 12 of horizontal deflection coil Vertical deflection coil 13 Insulation frame 14 Ferrite core

Claims (2)

A front panel having a phosphor screen formed on the inner surface;
A funnel joined to the front panel;
An electron gun housed in the neck of the funnel;
A cathode ray tube device provided on an outer peripheral surface of the funnel and comprising a horizontal deflection coil for deflecting an electron beam emitted from the electron gun in a horizontal direction and a deflection yoke including a vertical deflection coil for deflecting in a vertical direction. And
In the cross section including the tube axis, the thickness of the funnel at the first point on the outer surface of the funnel having the same position in the tube axis direction as the end of the horizontal deflection coil on the phosphor screen side is T1, The funnel at a second point on the outer surface of the funnel having the same position in the tube axis direction as the 7 mm position on the phosphor screen side along the tube axis from the phosphor screen side end of the horizontal deflection coil When the thickness of the funnel is T2, the funnel has an increase in the outer dimension of the funnel at the second point with respect to the first point, and the funnel at the second point with respect to the first point. A cathode ray tube device comprising at least one cross section including a tube axis that is larger than an increase in an inner dimension of the tube and satisfies T2 / T1 ≧ 1.18.   2. The cathode ray tube apparatus according to claim 1, wherein T2 / T1 ≧ 1.18 is satisfied in a cross section in which the thickness T <b> 1 is the smallest among a group of cross sections including a tube axis.

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