JP2722541B2 - Image display device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image display device in a video device.

2. Description of the Related Art Conventionally, a cathode ray tube is mainly used as a display device for displaying color television images, but a conventional cathode ray tube has a very long depth compared to a screen, and a thin television receiver is manufactured. It was impossible to do. Recently, EL display elements, plasma display elements, liquid crystal display elements, etc. have been developed as flat display elements.
All of them are insufficient in performance such as luminance, contrast, and color reproducibility of color display, and require time for practical use. In view of the above, an object of the present invention is to achieve a device capable of displaying a color television image on a flat display device using an electron beam. Each time, the electron beam is deflected in the vertical direction to display a plurality of lines, and further divided into a plurality of sections in the horizontal direction, and the phosphors such as R, G, B are sequentially emitted for each section, so that the The irradiation amount of the electron beam to the phosphor such as R, G, and B is controlled by a color video signal, so that a television image display element is formed as a whole.

Hereinafter, an example of the above-described conventional image display device will be described with reference to the drawings. FIG. 3 and FIG. 4 show a conventional image display device. In FIG. 3, 1 is a line cathode as an electron beam source, 2a and 2b are supports for supporting and fixing both ends thereof, 3 is a mesh-shaped control electrode, 4 is a phosphor, 5 is a back electrode, 6a, Reference numeral 6b denotes a container, and 7 denotes a spring for applying a load to the linear cathode 1 and extending the same. The operation of the thus configured image display device will be described below. The linear cathode 1 as an electron beam source is horizontally stretched by a leaf spring 7 attached to the supports 2a and 2b so as to generate an electron beam distributed linearly in the horizontal direction. A plurality of 1s are provided at appropriate intervals (only seven are shown here). This is the fourth
It is shown enlarged in the figure. The linear cathode 1 is supported by an insulating support 2 b fixed to the back electrode 5 and fixed by a leaf spring 7. The distance between the linear cathode 1, the control electrode 3 and the back electrode 5 is important in order to eliminate the variation in the luminance. For this reason, the pitch and depth are measured using an optical measuring device or the like. One V-groove 8 at one place, several μm
It is processed within the error within. These line cathodes 1 are formed by coating an oxide cathode material on the surface of a tungsten wire of, for example, φ10 to 20 μm. Then, control is performed by a control pulse so as to sequentially emit an electron beam at a constant time, and a heat current is supplied to raise the temperature to generate an electron beam at a time other than the predetermined time. At the start, the line cathode 1 is loaded with the above-mentioned control pulse for electron beam emission and the heat current at the same timing. The back electrode 5 suppresses the generation of electron beams from the other linear cathodes 1 other than the linear cathode 1 that is controlled to emit the electron beams at regular intervals, and pushes out the generated electron beams only in the forward direction. Works. The mesh-shaped control electrode 3 is passed through a long slit in the horizontal direction facing each of the linear cathodes 1, and is simultaneously deflected in the vertical or horizontal direction. A round hole may be used instead of the slit. The phosphor 4 is provided with a pair of phosphors of three colors R, G, and B for each one electron beam divided in the horizontal direction, and is applied in a stripe shape in the vertical direction. . And the container 6 which divided these components
After being inserted into a and 6b, they are sealed via a frit or the like to maintain the internal vacuum.

However, in the above configuration, as described above,
The distance between the linear cathode 1 and the control electrode 3 and the back electrode 5 is important, and there is a disadvantage that an error in the distance causes uneven brightness. To regulate this distance, one or one groove is formed. And the workability is poor, and since the contact area of the groove is large, the line cathode 1 is extremely thin, so that there is a drawback that the wire cathode 1 is easily broken.

In view of the above drawbacks, the present invention can easily regulate the distance between the linear cathode 1 and the control electrode, eliminate luminance unevenness, which is an image defect, and reduce the contact area of the groove to prevent disconnection. It is intended to provide an image display device capable of performing the following.

Means for Solving the Problems In order to solve the above problems, the image display device of the present invention,
The line cathode is fixed outside the groove end surface of the insulating support body having the groove and the image display portion, and is brought into contact with the outside diameter of the insulator provided inside the insulating support body. The fixing position is located above the bottom of the groove of the insulating support.

Action The present invention, by the above configuration, the linear cathode and the control electrode,
Alternatively, the position in the height direction between the line cathode and the back electrode is regulated by abutting the outer diameter of the insulator, or the line cathode is brought into contact with the groove end face of the insulating support to form a line cathode tube. By regulating the position, the unevenness in brightness was eliminated.In addition, the fixed position of the line cathode was provided above the bottom of the groove so that the bottom of the groove did not contact the line cathode. Therefore, there is an effect that an image defect due to disconnection does not occur.

Embodiment Hereinafter, an image display device according to an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, 11 is a conductive line cathode coated with a material having a thermionic emission function such as barium oxide, 12a and 12b are insulating supports for supporting and fixing both ends of the line cathode 11, and 13 is A power supply 14 for controlling the beam emitted from the linear cathode 11 to a predetermined image, 14
Is a phosphor that displays an image by emitting light when the beam passing through the control electrode 13 hits, 15 is a back electrode installed so that thermal electrons are easily generated from the linear cathode 11, 16a and 16b are containers, 17a and 1
7b is an insulator for positioning the wire cathode 11 in the height direction, 18
Is a spring that applies a load to the linear cathode 11 and stretches it.

In FIG. 1, insulators 17a and 17b
The distance between the line cathode 11 and the back electrode 15 or the control electrode 13 is maintained by contact with the outer diameter. Further, the insulators 17a and 17b are provided outside the image display section (that is, the phosphor 14) and further inside the insulating supports 12a and 12b, and correspond to the spiral cathode 11 shown in an enlarged scale in FIG. In contact. A groove 19 is provided in the insulating support 12b. The grooves 19 do not need to provide the processing accuracy of both the groove depth and the distance (pitch) between the line cathodes as in the related art, and need only provide the pitch accuracy only at the end faces of the grooves between the line cathodes, which facilitates the processing. There is no need to perform processing with a groove depth accuracy of several μm as in the related art. That is, the positioning in the height direction is performed by placing the linear cathode 1 on the insulator 17b.
1 is brought into contact, and the distance (pitch) between the linear cathodes is determined by the end face of the groove, so that the positioning in the height direction and the distance between the linear cathodes are performed. The fixed position of the wire cathode 11 is on the bottom of the groove.
Since the linear cathodes 11 on the groove bottom surface 19a are not in contact with each other because the linear cathodes 11 are fixed at the position 20 above the upper side 19a, the positioning accuracy in the height direction and the interval accuracy between the linear cathodes do not change. Furthermore, since the linear cathode 11 is not in contact with the groove bottom surface 19a, the contact resistance can be reduced. The linear cathode 11 is fixed by being tensioned and stretched over the linear cathode 11 and fixed to the spring 18. Here, reference numeral 20 denotes a fixed portion. The image display device is completed by assembling the control electrode 13 and the like on the assembled rear electrode 15 and sealing them with the containers 16a and 16b.

Advantageous Effects of the Invention As described above, the present invention is applicable to the case where the linear cathode is fixed outside the groove end face of the insulating support having the groove and the image display portion, and is further provided inside the insulating support. The gap between the back electrode and the line cathode or between the line cathode and the control electrode can be regulated by the contact of the insulator.Also, only the pitch processing of the grooves is required, so that there is no occurrence of luminance unevenness and the processing yield is also reduced. It can improve and reduce costs. Furthermore, since the line cathode is fixed without contacting the bottom of the groove, no contact resistance occurs, and the line cathode does not break, so that image defects do not occur and an inexpensive image display device can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an image display device according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a main part thereof, FIG. 3 is a partially cutaway perspective view showing a conventional image display device, FIG. The figure is an enlarged sectional view of the main part. 11 ... Line cathode, 12a, 12b ... Insulating support, 13 ... Control electrode, 14 ... Phosphor, 15 ... Back electrode, 17a, 17b ... Insulator, 19 ... Bottom of groove, 20 ... Fixed part.

 ────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-63-91927 (JP, A) JP-A-1-195641 (JP, A) JP-A-60-193246 (JP, A)

Claims (1)

(57) [Claims] 1. A line cathode for emitting electrons, a control electrode for controlling the flow of electrons, a phosphor capable of receiving and emitting the electrons, and a back electrode provided to emit the electrons from the line cathode. In the image display device having the above, an insulating support having a groove is provided, the end of the line cathode is fixed outside the groove end face of the insulating support and the image display portion, and provided inside the support. An image display device wherein the height of the line cathode is determined by contacting the outer diameter of the insulator, and the fixed position of the line cathode is above the bottom of the groove of the insulating support.