JPH0631062U - In-line color CRT - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain an in-line type color cathode ray tube that can reduce the deviation of convergence. [Structure] A rotation detection hole for detecting the horizontal axis between the electron beam horizontal axis of the electron gun and the Brown and a rotation detection hole are provided at positions apart from the electron beam trajectory of the electron gun.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an in-line type color cathode ray tube.

[0002]

[Prior art]

 2 is a cross-sectional view showing a conventional shadow mask type in-line color cathode ray tube, FIG. 3 is a cross-sectional view showing the electron gun in FIG. 2, and FIG. 4 is a schematic enlarged view of a grid portion of the electron gun in FIG. FIG. 5 is a cross-sectional view and FIG. 5 is a diagram of the converged lift phenomenon in the center of the screen. In FIG. 2, 1 is an electron gun, 2 is a funnel glass having one end connected to the electron gun 1, 3 is a panel glass connected to the other end of the funnel glass, and 4 is a lid provided on the inner surface of the panel glass 3. Light bodies, 5 are three electron beams output from the electron gun 1, 6 is a deflection yoke for electromagnetically deflecting the electron beam 5, and 7 is a shadow for selectively transmitting the electromagnetically deflected electron beam 5 into three colors of RGB. A mask, this shadow mask 7, is used to land the fluorescent bodies 4 of each color to emit light. Reference numeral 8 is an IMS composed of a magnetic plate that shields an external magnetic field. In FIGS. 3 and 4, 11 is a heater, 12 is a cathode, 13 is a first grid, 14 is a second grid, 15 is a third grid, 16 is a fourth grid, 17 is a rotation detection hole, and 18 is a 4-pole magnet. It's a ring.

Next, the operation will be described. The in-line CRT electron gun 1 shown in FIGS. 2 and 3 has three electron beams emitted from three cathodes 12 heated by three heaters 11 as shown in an enlarged view in FIG. The beam 5 passes through the first grid 13, is accelerated and focused by the second grid 14, the third grid 15, the fourth grid 16, etc., and reaches the fluorescent body 4 in FIG. Also, the orbit of the side beam is bent by the electron lens composed of the third grid 15 and the fourth grid 16, and the beams of the three screen centers are converged. The convergence of the screen center is corrected by the 4-pole magnet 18 mounted outside the neck. Here, in order to align the horizontal axes of the electron gun 1 and the funnel glass 2, rotation detection holes 17 are provided on both sides of the electron gun 1 as shown in FIG. The rotation of the electron gun 1 is accurately detected by.

[0004]

[Problems to be solved by the device]

 Since the conventional in-line type color cathode ray tube electron gun is configured as described above, the rotation detection hole 17 is on the same plane as the axes of the three electron beams 5, and therefore the portion where the rotation detection hole 17 is provided. However, there is a problem in that the electric field is not shielded by the electrodes and is greatly affected by the electric field in the neck portion, and the trajectory of the electron beam 5 is changed by the change in the electric field in the neck portion, resulting in a static convergence.

The present invention has been made in order to solve the above problems, and reduces the drift phenomenon of convergence with respect to the change in the neck potential of the cathode ray tube, and obtains an in-line type color cathode ray tube that obtains stable convergence. That is the purpose.

[0006]

[Means for Solving the Problems]

 The in-line type color cathode ray tube according to the present invention is provided with a rotation detecting hole of an electron gun at a position apart from the electron beam orbit.

[0007]

[Action]

 In the electron gun of the in-line type color cathode ray tube according to the present invention, the electric field is shielded by the electrodes, and the influence of the electric field on the trajectory of the electron beam is reduced.

[0008]

【Example】

 Example 1. An embodiment of the present invention will be described below with reference to the drawings. 1 is a sectional view showing an electron gun of an in-line type color cathode ray tube according to Embodiment 1 of the present invention. In the figure, 11 to 16 are the same as the conventional ones, and therefore their explanations are omitted. Reference numeral 9 is an electron gun, and 10 is a rotation detection hole provided in the third grid 15 of the electron gun 9. The rotation detecting hole 10 has a rectangular shape with a width of 1.0 mm and a length of 1.5 mm, and is arranged at a position, for example, 2 mm from the horizontal axis L of the electron beam so that the center of the width is parallel to the horizontal axis L as shown in the figure. Has been done.

Next, the operation will be described. As in the conventional case, in order to align the horizontal axes of the electron gun 9 and the funnel glass 2, the rotation detection holes 10 are provided on both sides of the side surface of the electron gun 9 as shown in FIG. The rotation of the electron gun 1 is accurately detected by the emitted light. At this time, since the rotation detecting hole 10 is arranged so as to avoid the horizontal axis L of the electron beam, the influence on the convergence is reduced by being shielded by the electric field.

Example 2. Although the rotation detecting hole is rectangular in the above embodiment, it is not limited to a rectangular shape and may be a square or a circle, and the distance from the horizontal axis of the electron beam is 3 to 5 mm. Demonstrate.

Example 3. In the above embodiment, the case where the rotation detecting hole is provided in the third grid has been described, but if the rotation detecting hole is provided in the grid capable of detecting the rotation of the electron gun, the same effect as that of the above embodiment is exhibited.

[0012]

[Effect of device]

 As described above, according to the present invention, the rotation detection hole is provided at a position separated from the electron beam orbit of the electron gun, so that there is no hole on the electron beam orbit and the electric field is shielded, thus affecting the convergence. The effect that can reduce is obtained.

[Brief description of drawings]

1 is a sectional view showing an electron gun according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a conventional in-line type color CRT.

FIG. 3 is a sectional view showing the electron gun in FIG.

FIG. 4 is a schematic enlarged cross-sectional view of a grid portion of the electron gun in FIG.

FIG. 5 is a diagram showing a convergence drift phenomenon in a screen center portion of a color CRT.

[Explanation of symbols]

 9 electron gun 10 rotation detection hole 11 heater 12 cathode 13 first grid 14 second grid 15 third grid 16 fourth grid

Claims (1)

[Scope of utility model registration request] 1. An in-line type color CRT having a rotation detection hole for detecting the horizontal axis of the electron gun and the horizontal axis of the cathode ray tube, wherein the rotation detection hole is separated from the electron beam trajectory of the electron gun. An in-line type color cathode ray tube characterized by being installed in a position.