JPS60235332A - Flat plate type cathode-ray tube - Google Patents

Abstract

PURPOSE:To uniformalize luminance per cathode and stabilize vertical deflection amplitude by providing an electron beam amount detection electrode outside at least a single effective screen of two or more electrodes arranged on the screen side of a vertical deflection electrode and an electron beam positional detection electrode outside at least the single effective screen. CONSTITUTION:To always obtain a constant current value and then obtain a picture with uniform luminance by detecting the beam current value that flows in a first beam current detection electrode 15 provided outside an effective screen and controlling the voltage of a beam extraction electrode 3 based on the said value. In addition, the beam current when it arrives at the position of a normal screen previously is detected from a second beam current detection electrode 16 with a wedged-shaped aperture 16' in the vertical direction and a third beam current detection electrode 17 and stored in a memory circuit 65. The position of the screen at which the beam arrives is held accurately by always comparing this stored signal and subsequent beam flow-in current values using a comparator 66 and controlling the beam position.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a flat cathode ray tube.

Conventional structure and its problems Conventionally, as a flat cathode ray tube, Japanese Patent Application Laid-Open No. 57-133778
No. 2 is proposed. This is shown in FIG.

In this figure, from the back to the front, the back electrode 1, the linear cathode 2 as an electron beam source, the beam extraction electrode 3, the vertical focusing and deflection electrode 4, the first shield electrode 6, and the electron beam flow control electrode 6. , second shield electrode 7,
A horizontal focusing and deflecting electrode 8, a third shield electrode 9, an electron beam accelerating electrode 1o and a screen 11 are arranged. A linear cathode 2 serving as an electron beam source is stretched horizontally so as to generate a linear electron beam in the horizontal direction, and a plurality of such cathodes 2 are provided vertically at appropriate intervals. . In this embodiment, it is assumed that 16 pieces are provided. These cathodes 2 are constructed by coating an oxide cathode material on the surface of a tungsten wire having a diameter of 10 to 20 μm, for example. In order to extract the beam from the cathode 2 toward the beam extraction electrode 3, the potential of the back electrode 1 is lower than that of the cathode 2, and the potential of the beam extraction electrode 3 is higher than that of the cathode 2. The electron beam emitted from the cathode 2 in this manner passes through the aperture 3' of the beam extraction electrode 3 and advances to the region of the vertical focusing/deflection electrode 4. A plurality of vertical focusing/deflecting electrodes 4 are disposed between each of the apertures 3' of the beam extraction electrode 3, and are used to direct the electron beam in the vertical direction using an electrostatic lens formed between the first shield electrode 5 and the next first shield electrode 5. At the same time, a vertical deflection voltage is applied between the facing vertical focusing/deflecting electrodes 4 to deflect the electron beam in the vertical direction. In this configuration example, the electron beam from one cathode 2 is vertically deflected by 16 horizontal lines. Therefore 15 cathodes 2
When all are driven, the electron beam is deflected to draw 240 horizontal lines on the screen.

Next, the control electrodes 6 are composed of conductive plates 62 each having a vertically long slit 61, and a plurality of control electrodes 62 are arranged horizontally in parallel at predetermined intervals. Each of the control electrodes 6 extracts the electron beam by dividing it into one picture element in the horizontal direction, and controls the amount of electron beam passing through the electron beam in accordance with a video signal for displaying each picture element. Therefore, if 32,020 control electrodes 6 are provided, 320 pixels can be displayed per horizontal line. In addition, each picture element is R and G in order to display images in color.

Display is performed using a three-color B phosphor, and each of the R, G, and B video signals is applied to each control electrode 6. A video signal for one line is simultaneously applied to each control electrode 6. and one line of video is displayed simultaneously.

The horizontal focusing/deflection electrode 8 is composed of a plurality of conductive plates arranged vertically in the middle of each of the slits of the control electrode 6, and a horizontal deflection voltage is applied between each conductive plate, so that each picture is Each element's electron beam is deflected in the horizontal direction, and R, G, and H phosphors are sequentially irradiated on the screen to emit light. In this embodiment, the deflection range is 0, which is a width of one picture element for each electron beam. At the same time, the electron beams for each picture element divided in the horizontal direction are focused in the horizontal direction.

Note that the first thing. Second. The third shield electrodes 5, 7.9 are conductive plates each having a plurality of vertically long slits facing the slits of the control electrode 6.

The electron beam accelerating electrode 10 is composed of a plurality of conductive plates installed horizontally at the same position as the vertical focusing/deflecting electrode 4, and has the effect of accelerating the electron beam and expanding the vertical deflection at the same time. .

The screen 11 is constructed by applying a phosphor 2o that emits light when irradiated with an electron beam to the inner surface of a glass plate 21, and adding a metal bank layer (not shown).

The phosphor 20 is attached to one slit hole of the control electrode 6,
In other words, one set of three-color phosphors, R, G, and B, is provided for each beam divided in the horizontal direction.
It is applied in vertical stripes. In FIG. 1, the broken lines drawn on the screen 11 indicate divisions in the vertical direction corresponding to each of the plurality of cathodes 2, and the two-dot chain lines correspond to each of the plurality of control electrodes 6. Indicates the horizontal division displayed.

The flat cathode ray tube with the configuration described above uses multiple line cathodes and multiple control electrodes to deflect the electron beam vertically and horizontally for each block, forming a single overall image on the screen. It is something that is synthesized.

However, when combining multiple images on a screen to create one overall image, the brightness of each block and the spacing between horizontal lines (scanning lines) are strictly required to be uniform, and the driving The problem was that it was difficult to manufacture because circuit stability was also required.

Purpose of the Invention In view of the above-mentioned drawbacks, the present invention provides a flat cathode ray tube capable of achieving uniformity of brightness for each cathode and stability of vertical deflection amplitude during image synthesis in the flat cathode ray tube. It is something to do.

Structure of the Invention In order to achieve the above object, the flat cathode ray tube of the present invention extends horizontally a plurality of electrodes arranged after vertically deflecting an electron beam to outside the effective screen, and extends the electrodes into and out of the effective screen. The beam current is detected from one electrode outside the effective screen and fed back to the drive circuit of the back electrode or beam extraction electrode, and the other electrode outside the effective screen is wedged vertically. The vertical amplitude and beam position of each cathode are detected based on the beam transmittance passing through the aperture, and the vertical deflection circuit is controlled by this detection signal.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Second
The figure shows one embodiment of the electrode configuration from the back electrode 1 to the beam current detection electrode. Components corresponding to those shown in FIG. ing. Therefore, the other electrodes 1 to 4 also extend outside the horizontal effective screen.

The first beam current detection electrode 15 may or may not have a slit or a circular opening, and is separated from the electrode 6 within the effective screen. The second beam current detection electrode 16 is also separated from the electrode 5 and is provided with a wedge-shaped aperture 16' over the vertical scanning area of each cathode. Further, the third beam current detection electrode 17 is separated from the electron beam current control electrode 6 within the effective screen, and the third beam current detection electrode 17 is separated from the electron beam current control electrode 6 within the effective screen. Second beam current detection electrode 15
．． 16.

FIG. 3 shows an embodiment of a control system for uniformizing the beam current for each cathode in a flat cathode ray tube having the above electrode configuration.

The beam that has passed through the beam extraction electrode 3 is focused and deflected by the vertical focusing/deflection electrode 4, so that a certain DC current that is not modulated by the first image signal etc. is incident, and this current is sent to the detector. Detected at 31. The first beam current detection electrode 15 is then compared with a required predetermined current value, and the difference is inputted to the beam extraction electrode voltage control circuit 32 to control the voltage supplied to the beam extraction electrode 3.
The beam current incident on the beam can always be kept at a predetermined constant current value. It goes without saying that the beam current may be detected by the third beam current detector 17-2.

By performing the above operations in each cathode region, uniform brightness at both peaks can be obtained over each cathode region.

Next, a method for stabilizing the vertical scanning amplitude and the position where the beam reaches the screen will be described.

FIG. 4 is a vertical cross section of the configuration shown in FIG.
0? −? -f1 juice hand blind force C
16 electron beams 26 on each cathode region,
At this time, the joint of the vertical scanning area of each cathode 2, that is, the position on the screen of the electron beam 26 in FIG. The distance between V1-16 and the position (2-1) where the electron beam 26' arrives on the screen must be equal to the vertical scanning interval for each cathode. For this reason, as shown in FIGS. 2 and 6, an opening 16' is provided in the second beam current detection electrode 1 provided outside the effective screen of the first shield electrode 5.
The amount of beam flowing into this electrode 16 and the amount of beam passing through the aperture 16' and flowing into the third beam current detection electrode 17-1 provided outside the effective screen of the control electrode 6 are detected, and the screen arrival position of the beam is detected. and control the beam so that it reaches the correct position.

FIG. 6 shows an example of this. First, at the stage where the electron beam is adjusted so that it is incident on the correct position on the screen as an initial adjustment, the beam current flowing into the second beam current detection electrode 16 and the third beam current detection electrode 17-1 is adjusted for each horizontal scan. The detector 61.62vc detects the signal every hour and inputs it to the comparator 63. The comparator 63 calculates the difference or ratio between the respective incoming beam current values, and inputs this into the memory circuit 65 by turning the switch 64 to the a side.

As described above, the second beam current detection electrode 16 is provided with the wedge-shaped opening 16', so that when the beam is deflected in the vertical direction, the beam current detection electrodes 16 and 17- Since the beam currents flowing into the screen are different, the difference or ratio between the two can be associated with the position where the beam reaches the screen.

When the above input operations are completed, the written information is read out from the memory circuit 65 in synchronization with vertical and horizontal scanning. On the other hand, after that, the second and third beam current detection electrodes 1
By constantly detecting the beam current flowing into 6, 17-1 and comparing the two, and turning the switch to the b side, the aWH from the comparator 63 and the output read from the memory circuit 66 are output to the comparator 66. When a difference occurs between the two, the difference signal is input to the vertical deflection control circuit 67, and the voltage applied to the vertical focusing/deflection electrode 4 is controlled so as to correct the electron beam position.

FIG. 7 shows another embodiment for controlling the electron beam position.

When the beam current incident on the first shield electrode 5 is controlled to a constant value as explained in FIG. 3, the second beam current detection electrode 16 and the third
There is no need to detect current from both of the beam current detection electrodes 17-1, and it is possible to correlate only the beam current value flowing into one of the electrodes with the beam position reaching the screen. Therefore, in this embodiment, the second beam current detection electrode 16. Alternatively, the beam current is detected by the detector 71 from any one of the third beam current detection electrodes 17-1.
As in the embodiment of FIG. 6, the output of the detector 71 is input to the memory circuit 73 after initial adjustment.

Thereafter, the switch 72 is turned to the b side, and the output of the detector 71 and the value of the current flowing into the beam current detection electrode arranged after the vertical deflection electrode are stored as 0 as explained above in the embodiments of FIGS. 6 and 7. By associating the beam position with the position of the beam arriving on the screen, it is possible to ensure that the beam always reaches the correct position on the screen.

In the above embodiment, the beam current detection electrodes were provided at the positions of the first shield electrode and the control electrode, but it is of course possible to use any electrode after vertical deflection.

As described in detail of the invention, by detecting the value of the beam current flowing into the first beam current detection electrode provided outside the effective screen and controlling the voltage of the beam extraction electrode based on this,
A constant current value is always obtained, a uniform brightness image is obtained, and a normal value is detected in advance from the second beam current detection electrode and the third beam current detection electrode, which have wedge-shaped openings in the vertical direction, and this is stored. However, by constantly comparing this stored signal with subsequent beam inflow current values to control the beam position, it is possible to accurately maintain the position on the screen where the beam reaches.

[Brief explanation of the drawing]

FIG. 1 is an internal perspective view showing the basic configuration of a conventional flat cathode ray tube, FIG. 2 is a perspective view showing the main electrode configuration of a flat cathode ray tube according to the present invention, and FIG. 3 is a flat cathode ray tube according to the present invention. 4 is a vertical sectional view of an embodiment of the flat cathode ray tube according to the present invention; FIG. A perspective view of three-beam current detection electrodes, and FIGS. 6 and 7 are beam position control circuit diagrams in a flat plate cathode ray tube according to the present invention, respectively. 1...Back electrode, 2...Striated cathode, 3...
・Beam extraction electrode, 4... Vertical focusing/deflection electrode, 5... First shield electrode, 6... Electron beam downstream side... Electron beam accelerating electrode, 11... ...
-Screen, 15...First beam current detection electrode, 16...Second beam current detection electrode, 17...
...Third beam current detection electrode, 31.61.62,7
1... Beam current detector, 63.66.74.
・・・Comparator, 65.73・Memory circuit, 67.7
5. Vertical deflection control circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 5 Figure 6 Figure 7 Procedural Amendment Document October 1988 / Date 1 Display of the case 1988 Patent Application No. 90610 Relationship with the person making the amendment 3 Patent Application Address Osaka 1006 Kadoma, Fukadoma City Name (
582) Matsushita Electric Industrial Co., Ltd. Representative Toshihiko Yamashita 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Target of 6 corrections "M41' (7)% W8%; IJ' :”-Oa d)6
, Contents of amendment (1) The scope of claims in the specification will be amended as shown in the attached sheet. (2) "Multiple electrodes" on page 8, line 7 of the specification is replaced with "
At least one of the plurality of electrodes is corrected and removed. (3) Correct "one electrode" in line 9 of page 8 to "at least one electrode" and omit it. (4) On page 8, lines 11 to 13, "feed back ~ depending on the transmittance" is changed to "feedback, and at least one of the electrodes extended outside the effective screen reaches the screen. An electrode is placed to detect the position of the electron beam, and this electrode makes corrections. (5) ``1'' provided in 1 on page 14, line 13 is amended to ``provided'' and omitted. (6) In the same page 14, lines 1γ to 19, “in the vertical direction ~ from the detection electrode,” was replaced with “by the beam position detection electrode,”
” and correct it. will be deleted. 2. Claims (1) A linear force hood, a back electrode and a beam extraction electrode arranged on both sides of the linear cathode, and a vertical deflection electrode that vertically deflects the electron beam extracted from the beam extraction electrode. and a plurality of electrodes arranged on the screen side of the vertical deflection electrode, an electron beam amount detection electrode arranged outside the effective screen of at least one of the plurality of electrodes, and at least one of the plurality of electrodes. A flat cathode ray tube characterized in that electrodes for detecting the position of an electron beam reaching the screen are arranged outside the effective screen of the tube. (2) The electron beam amount detection electrode is electrically separated within the effective screen and outside the effective screen, and the first electrode through which the beam passes has an aperture with the same aperture ratio for the electron beam. A flat cathode ray tube according to claim 1, characterized in that: (3) The flat cathode ray tube according to claim 1, wherein the electron beam amount detection electrodes are electrically separated within the effective screen and outside the effective screen, and the electrodes outside the effective screen are non-porous. (4) The electron beam position detection electrode is electrically separated inside and outside the effective screen, and is further separated from the electron beam amount detection electrode, and the first electrode through which the beam passes has a beam transmittance in the vertical direction. A flat cathode ray tube according to claim 1, characterized in that the cathode ray tube has different shapes. (6) Detect the electron beam current flowing into the electron beam amount detection electrode, feed it back to the beam extraction electrode voltage control circuit, and control the electron beam current flowing into the beam extraction electrode to a predetermined current value. A flat cathode ray tube according to claim 1, characterized in that: (6) The signal from the beam position detection electrode when the electron beam is incident on the correct position on the screen is stored in a memory circuit, and then the signal from the beam position detection electrode and the signal from the beam position detection electrode are input into the memory circuit during actual operation. The flat cathode ray tube according to claim 1, wherein the vertical deflection amount is controlled by comparing the signals so that the electron beam always enters the correct position on the screen.

Claims (1)

[Claims] (1) A linear cathode, a back electrode and a beam extraction electrode arranged on both sides of the linear cathode, a vertical deflection electrode that vertically deflects the electron beam extracted from the beam extraction electrode, and a vertical deflection electrode that vertically deflects the electron beam extracted from the beam extraction electrode. a plurality of electrodes arranged on the screen side, an electron beam amount detection electrode is arranged outside the effective screen of at least one of the plurality of electrodes, and an electron beam amount detection electrode is arranged outside the effective screen of at least one other of the plurality of electrodes; A flat cathode ray tube characterized by having electrodes arranged to detect the position of an electron beam reaching a screen. (The electron beam amount detection electrode is electrically separated inside the effective screen and outside the effective screen, and the first electrode through which the beam passes has an aperture with the same aperture ratio for the electron beam.) A flat cathode ray tube according to claim 1.('4) The electron beam amount detection electrodes are electrically separated within the effective screen and outside the effective screen, and the electrodes outside the effective screen are A flat cathode ray tube according to claim 1, which is non-perforated. A flat cathode ray tube according to claim 1, characterized in that the first electrode through which the beam passes is provided with a horizontal aperture that is long in the vertical direction. A patent claim characterized in that the electron beam current flowing into the beam extraction electrode is detected and fed back to a beam extraction electrode voltage control circuit to control the electron beam current flowing into the beam extraction electrode to a predetermined current value. The flat cathode ray tube described in item 1. (@ The signal from the beam position detection electrode when the electron beam is incident on the regular position on the screen is stored in a memory circuit, and then the beam position is detected during actual operation. Claims characterized in that the amount of vertical deflection is controlled so that the electron beam always enters the correct position on the screen by comparing the signal from the electrode and the signal input to the memory circuit. The flat cathode ray tube according to item 1.