JP2543157B2 - 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 has been mainly used as a display element for displaying a color television image, but in the conventional cathode ray tube, the depth is much longer than the screen, and a thin television receiver is manufactured. It was impossible to do. Also, as flat plate display elements, EL display elements, plasma display elements, liquid crystal display elements, etc. have been recently developed.
All of them are insufficient in terms of performance such as brightness, contrast and color reproducibility of color display, and it requires time for practical use. Therefore, for the purpose of achieving a device capable of displaying a color television image on a flat display device using an electron beam, the screen on the screen is divided into a plurality of sections in the vertical direction. The electron beam is deflected vertically for each line to display multiple lines, and it is further divided into multiple sections in the horizontal direction to create RGB for each section.
And the like, and the irradiation amount of the electron beam to the RGB and other fluorescent bodies is controlled by a color video signal, thereby forming a television image display device as a whole.

An example of the above-described conventional image display device will be described below with reference to the drawings. 5 and 6 show a conventional image display device. In FIG. 5, 1 is a wire cathode as an electron beam source, 2a and 2b are support bases for supporting and fixing both ends thereof, 3 is a mesh-shaped control electrode, 4 is a fluorescent body, 5 is a back electrode, and 6a. 6b is a container, and 7 is a spring that applies a load to the wire cathode 1 to stretch it.

The operation of the image display device thus configured will be described below. The wire 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 linearly distributed in the horizontal direction. A plurality of 1's are provided at appropriate intervals. (Here, only seven are shown.) This is enlarged and shown in FIG. The wire cathode 1 is supported by an insulating support 2b fixed to the back electrode 5 and fixed by a leaf spring 7. In order to eliminate variations in brightness, the spacing between the line cathode 1, the control electrode 3 and the back electrode 5 is important. Therefore, while measuring the pitch and depth dimensions using an optical measuring instrument, etc. The V groove portion 8 is processed in one place and within an error within a few μm. These wire cathodes 1 are formed by coating an oxide cathode material on the surface of a tungsten wire having a diameter of 10 to 20 μm, for example. Then, it is controlled by a control pulse so that the electron beam is sequentially emitted for a certain period of time, and a heating current is supplied to raise the temperature to generate the electron beam at a time other than the certain period of time. Also, at the start, the line cathode 1
The above-mentioned control pulse for electron beam emission and the heating current are loaded at the same timing. The back electrode 5 suppresses the generation of the electron beam from the other line cathodes 1 other than the line cathode 1 which is controlled to emit the electron beam for a certain period of time, and pushes out the generated electron beam only in the forward direction. The working mesh-shaped control electrode 3 passes through the horizontally long slits facing the respective line cathodes 1 and, at the same time, deflects it vertically or horizontally. A round hole may be used instead of the slit.

The fluorescent bodies 4 are provided with one pair of fluorescent bodies of three colors of RGB for each electron beam divided in the horizontal direction, and are applied in stripes in the vertical direction. After these components are inserted into the divided containers 6a and 6b, they are sealed with a frit or the like to keep the internal vacuum.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above configuration, as described above,
The interval between the line cathode 1 and the control electrode 3 and the back electrode 5 is important, and there is a drawback that unevenness in brightness occurs due to an error in this interval. In order to regulate this interval, one or one groove is processed. However, the workability is poor, and the contact area of the groove is large. Therefore, the wire cathode 1 is extremely thin, which is easily broken.

In view of the above-mentioned drawbacks, the present invention can easily regulate the distance between the line cathode 1 and the control electrode 3 to eliminate the uneven brightness which is an image defect, and further, because the contact area of the groove portion is small, there is no disconnection. The present invention provides the image display device.

Means for Solving the Problems In order to solve the above problems, the image display device of the present invention is, outside the image display unit, an insulator for performing positioning in the height direction of the line cathode, and between the line cathodes. An insulating support having a groove for positioning the gap is provided, and the groove of the insulating support has a step in which the width of the groove of the groove becomes wider on the outer side when the image display device is viewed in plan. The wire cathode has a spring which is brought into contact with the insulator, the end face of the groove of the insulating support and two corners of the stepped groove in order, and a spring which is located outside the insulating support. , Is fixed and stretched at a position different from the extension of the two points of the corners of the stepped groove of the insulating support.

Operation According to the present invention, the wire cathode is brought into contact with the groove end face of the stepped groove provided in the insulating support and the two corners of the stepped groove by the above-mentioned configuration, and the interval (pitch) between the line cathodes is increased. By controlling the position, the occurrence of uneven brightness is eliminated. Furthermore, the contact angle of the wire cathode with the groove is reduced by the contact with the two corners of the stepped groove, reducing the contact resistance and disconnecting the wire cathode. Since it does not occur, image defects due to disconnection do not occur.

Example An image display apparatus according to an example of the present invention will be described below with reference to the drawings. In FIG. 1, 11 is a conductive line cathode coated with a substance having a thermionic emission function such as barium oxide, 12a and 12b are insulating supports for supporting both ends of the line cathode 11, and 13 is the line. An electrode that controls the beam emitted from the cathode 11 to form a predetermined image, 14 is a fluorescent body that emits light to display an image when the beam that has passed through the control electrode 13 collides, and 15 is a line cathode 11 Back electrodes installed so that thermoelectrons are easily generated, 16a, 16b are containers, 17
a and 17b are insulators for positioning the wire cathode 11 in the height direction, 1
Reference numeral 8 denotes a spring that applies a load to the wire cathode 11 to stretch it.

In FIG. 1, the insulators 17a, 17
The line cathode 11 provided with b is kept in contact with the outer diameter of the line cathode 11 and the back electrode 15 or the control electrode 13.
Further, the insulators 17a and 17b are provided outside the image display section (that is, the fluorescent body 14) and inside the insulating supports 12a and 12b, and contact the line cathode 11 as shown in an enlarged view in FIG. Touching.

As shown in FIG. 2, the insulating support 12b has a stepped groove 19 whose width is wider on the outer side when the image display portion is viewed in plan.
Is provided. This stepped groove 19 does not need to have the processing precision of both the groove depth and the interval (pitch) between the line cathodes 11 as in the conventional case, and the groove end surface 19 of the stepped groove 19 between the line cathodes 11 is not required.
If only a is pitch accurate, processing becomes easy. The groove depth accuracy does not need to be processed with a processing accuracy of several μm as in the conventional case. That is, the positioning in the height direction is performed by bringing the wire cathodes 11 into contact with the insulator 17b, and the distance (pitch) between the wire cathodes 11 is determined by the groove end surface 19a of the stepped groove 19. Positioning in the height direction and positioning of the cathode spacing are performed.

As shown in FIG. 2, when the wire cathode 11 is brought into contact with the end surface 19a of the stepped groove 19 provided in the insulating support 12b and the wire cathode 11 is fixed to the spring 18, the spring 18 is Since the line cathode 11 is displaced from the line of the stepped groove 19 to the corner 19c side of the stepped groove 19, it is ensured that the line cathode 11 is brought into contact with the groove end face 19a and the corners 19b, 19c of the stepped groove 19. become.
Further, the angle formed by the corners 19a, 19b of the stepped groove 19 and the line cathode 11 is set smaller than the angle formed by the line cathode 11 and the fixing portion of the spring 18, and the line cathode 11 is smoothly formed by the step. Groove
The groove end faces 19a, 19b, 19c of 19 are brought into contact with each other. Therefore, the contact resistance applied to the line cathodes 11 can be reduced, disconnection can be prevented, and the accuracy of the interval (pitch) between the line cathodes 11 is not disturbed.

FIG. 3 is a main part enlarged plan view showing a second embodiment of the present invention. In this figure, parts corresponding to those in FIG. 2 are designated by the same reference numerals. In this example, instead of the stepped groove 19, a groove (hereinafter referred to as an R-shaped groove) 20 having a curved surface whose width is wider on the outer side when the image display unit is viewed in plan is adopted. . When the wire cathode 11 is brought into contact with the groove end surface 20a of the R-shaped groove 20 provided in the insulating support 12b and the wire cathode 11 is fixed to the spring 18, the spring 18 has a radius R from the line of the wire cathode 11. Since the groove 20 is arranged on the R portion 20b side of the groove 20,
The line cathode 11 is surely brought into contact with the groove end face 20a and the R portion 20b of the R-shaped groove 20.

Further, the radius of the R portion 20b of the R-shaped groove 20 is set to
Since the size of 1 is set so as not to bend, the wire cathode 11 smoothly moves the groove end face 20a of the groove 20 with R and the R portion 2
It comes into contact with 0b. Therefore, the contact resistance applied to the line cathodes 11 can be reduced, disconnection can be prevented, and the interval (pitch) accuracy between the line cathodes 11 can be kept constant.

The line cathode 11 is fixed by applying tension to the line cathode 11 and stretching it and fixing it to the spring 18. The image display device is completed by sealing the control electrode 13 and the like to the assembled back electrode 15 with the assembling containers 16a and 16b.

EFFECTS OF THE INVENTION As described above, according to the present invention, the linear cathode is provided with the stepped groove and the end surface of the groove portion of the insulating support having the stepped groove whose outer side is wider when viewed in plan. Abutting at two corners, or abutting on the end surface of the groove portion of the insulating support having a curved surface such that the outer side of the image display portion becomes wider when viewed in plan, Since it is only necessary to process the pitch of the groove portion, uneven brightness is eliminated, the processing yield is improved, and the cost can be reduced.

Further, since the contact angle of the linear cathode with respect to the groove is reduced by the two corners of the stepped groove, the contact resistance is reduced and the linear cathode is not broken, so that it is possible to provide an inexpensive image display device without causing an image defect. become.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an image display device according to an embodiment of the present invention, FIG. 2 is an enlarged plan view of an essential part of a back electrode block in the first embodiment, and FIG. 3 is a back view in the second embodiment. An enlarged plan view of an essential part of the electrode block, FIG. 4 is an enlarged sectional view of an essential part of the back electrode block, FIG. 5 is a partially cutaway perspective view showing an image display device of a conventional example, and FIG. 6 is an essential part thereof. It is an expanded sectional view. 11 ... Wire cathode, 12a, 12b ... Insulating support, 13 ... Control electrode, 14 ... Fluorescent material, 15 ... Rear electrode, 19 ... Stepped groove,
19a …… Groove end face, 19b, 19c …… Corner, 20 …… R groove, 20
a: groove end face, 20b: R part.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Keiji Nagata 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A-1-195641 (JP, A) JP-A-2 -121239 (JP, A) JP-A 2-117056 (JP, A) Actually open 61-60457 (JP, U) Actually open 52-74752 (JP, U) Actually open 51-163862 (JP, U) )

Claims (2)

(57) [Claims] 1. A line cathode which emits electrons, a control electrode which controls the flow of electrons, an image display unit which is made of a phosphor capable of receiving the electrons and emits light, and the electron which is emitted from the line cathode. In an image display device having a back electrode provided, outside the image display unit, an insulator for positioning in the height direction of the wire cathode, and for positioning the spacing between the wire cathodes An insulating support having a groove is provided, and the groove of the insulating support has a step in which the width of the groove of the groove becomes wider on the outer side when the image display device is seen in a plan view, The wire cathode is brought into contact with the insulator and the groove end surface of the insulating support and two corners of the stepped groove in order, and the wire cathode is attached to the spring located outside the insulating support. Different from the extension of the two points of the corner of the stepped groove Fixed in location, the image display apparatus characterized by being stretched. 2. A line cathode which emits electrons, a control electrode which controls the flow of electrons, an image display unit which is made of a phosphor capable of receiving the electrons and emits light, and the electron which is emitted from the line cathode. In an image display device having a back electrode provided, an insulating material for positioning in the height direction of the wire cathode, and an outside for positioning the spacing between the wire cathodes, outside the image display unit. An insulating support having a groove is provided, and the groove of the insulating support has a step in which the width of the groove of the groove becomes wider on the outer side when the image display device is seen in a plan view, The wire cathode is brought into contact with the insulator and the groove end surface of the insulating support in order, and is different from the extension line of the groove end surface of the insulating support on the spring located outside the insulating support. Fixed in position and suspended An image display device comprising and.