JPS61121682A - Driving method of flat plate cathode ray tube - Google Patents

Abstract

PURPOSE:To eliminate a color blur which occurs due to a variance of landing in the horizontal direction, and to execute the true color picture display by detecting a timing signal in which respective beams scan the prescribed phosphor position, storing this, and controlling, in correspondence to a fluorescent screen position of the beam, the timing of the video signal impressed to a modulating electrode of a flat plate cathode ray tube based upon the stored signal. CONSTITUTION:The scanning is started from the position which will not scan a phosphor of R of an adjoining horizontal block, and by receiving thrugh a filter 52 at a photoelectric converting element 53, a timing signal is obtained. A reference signal for reading the same frequency as the reference signal generated when the writing to a memory is executed, is synchronized with a horizontal synchronizing signal and generated. The signal obtained from the second line memory 58 is converted to an analog signal at a D/A converter 59, amplified by an amplifier 60 and impressed to a modulating electrode of a flat plate cathode ray tube 51.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for driving a flat cathode ray tube used in color television receivers, computer terminal displays, and the like.

Conventional Structure and Problems There is a prior art planar cathode ray tube created by the present applicant with a structure shown in FIG. In reality, each electrode is housed in a vacuum envelope (glass container), but
In the figure, the vacuum envelope is omitted to make the internal electrodes clear. Further, in order to clarify the horizontal and vertical directions of the screen on which images, characters, etc. are displayed, a horizontal direction H and a vertical direction V1 are shown on the face plate portion.

First, a plurality of vertically long linear cathodes 1o each having an oxide formed on the surface of a tungsten wire are independently arranged at equal intervals in the horizontal direction. The number of linear cathodes 10 and the spacing between them are arbitrary. For example, if the display screen size is 10 mm, the horizontal spacing between the 20 linear cathodes is approximately 10 mm, and the 20 linear cathodes are arranged vertically. about 1 in the direction
They are arranged with a length of 60 mm. On the opposite side of the face plate portion 9 across the linear cathode 1o, the linear cathode 1° scanning electrode 12 has a linear cathode 1° scanning electrode 12 that is arranged in a vertical direction to display the number of horizontal scanning lines (NTSC system) when displaying a normal television image. (approximately 480 electrodes) are formed as independent electrodes. Next, between the linear cathode 10 and the 7-ace plate 9, from the linear cathode 10 side, planar electrodes each having an opening in a portion corresponding to the linear cathode 1o are divided between adjacent cathodes. , a first grid electrode (hereinafter referred to as G1) 13 that performs beam modulation by applying a video signal to each of the electrodes.
．． A second grid electrode (hereinafter referred to as G2) 14 that has the same openings as the G1 electrode 13 and is not electrically divided in the horizontal direction.
, a third grid electrode (hereinafter referred to as G3) 15 is arranged. Next, G2 electrode 14. The fourth grid electrode (hereinafter referred to as G4) has an aperture that is the same as the aperture of the G3 electrode 16 or is wider in the horizontal direction.
) 16 is placed. Next, a horizontal focus electrode 17 is formed on the surface of the insulating support 19 by plating or vapor deposition.
The horizontal deflection electrodes 18 are arranged symmetrically about each electron beam axis and at the same intervals as the cathode intervals in the horizontal direction.

A light emitting layer consisting of a phosphor 7 and a metal back electrode 8 is formed on the inner surface of the face plate 9.

In the case of color display, the phosphors are formed as stripes or dots of red R2, green G, and back B sequentially in the horizontal direction.

Next, FIG. 2 shows the operation of the color cathode ray tube.

This will be explained using FIG. The linear cathode 10 is heated by passing a current through it, and the same voltage as the potential of the cathode 10 is applied to the G1 electrode 13 and the vertical scanning electrode 12. At this time G1. The beam advances from the cathode 10 toward the G2 electrode (13, 14), and a voltage (1
00-300V) is applied to the iG2 electrode 14. Here the beam is G1. The amount of light passing through each hole of the G2 electrode is controlled by changing the voltage of the G1 electrode 13. The beam passing through the aperture of the G2 electrode 14 is transferred to the G3 electrode 1e.
Proceeding from s-G4 electrode 16 → horizontal focus electrode 17,
A predetermined voltage is applied to these electrodes so that the electron beam forms a small spot on the fluorescent surface. Here, the beam focus in the vertical direction is performed by an electrostatic lens formed at the exit of the aperture of the G4 electrode 16, and the beam focus in the horizontal direction is performed by an electrostatic lens formed between the horizontal focus electrode 17 and the horizontal deflection electrode 18. It is done with a lens. The beam that has passed through the horizontal focus electrode 17 is deflected to the horizontal deflection electrode 18 by a predetermined width in the horizontal direction by a sawtooth wave or staircase wave deflection voltage with a horizontal scanning period, and stimulates the phosphor 7 to produce a luminescent image. obtain. To obtain a color image, as described above, when each electron beam horizontally scans the phosphor 7, a modulation signal of color t corresponding to the color phosphor on which the electron beam is incident is applied to the 01 electrode 13. be done.

Next, vertical scanning will be explained by referring to the entire circumference of FIG.

As described above, by controlling the voltage of the vertical scanning electrode 12 so that the potential of the space surrounding the linear cathode 10 is more positive or negative than the potential of the linear cathode 1o, the voltage from the linear cathode 10 is The generation of electrons is controlled. At this time, if the distance between the linear cathode 1o and the vertical scanning electrode 12 is small, the beam from the cathode can be turned on or off.
The voltage to control it may be small. When the vertical scanning electrode 12 uses an interlace method, the first one
In the field, a beam is generated from 12A of the vertical scanning electrode for one horizontal scanning period (hereinafter referred to as 1H) (hereinafter referred to as O).
N) During 1H when the signal is primary, a signal that turns on the beam is applied to 12C, and then a signal that turns on the beam only for 1H is applied to every other vertical scanning electrode, and then
When 2X is completed, the vertical scanning of the first field is completed. The next second field is 1H from 12B.
A signal is applied to turn on the beam only during the period, and finally 1
One frame of vertical scanning is completed by scanning up to 2Y.

Next, we will explain a generally well-known method for the signal processing system until the video signal is applied to the beam modulation electrode of a cathode ray tube that has a plurality of beam generation sources in the horizontal direction, such as the above-mentioned flat-type cathode ray tube. This will be explained using Figure 4.

Timing pulse generator 4 based on TV synchronization signal 42
4, a timing pulse is generated to drive a circuit block to be described later. First, the three primary color signals (ER, EG, E
B) 41 is converted into a digital signal by the A/D converter 43, and the 1H signal is sent to the first line memory circuit 4.
Enter 5.

When all the signals for 1H are input, the signals are simultaneously transferred to the second line memory circuit 46, and the next 1H signal is input to the first line memory circuit 45.

The signal transferred to the second line memory circuit 46 is 1H
During this period, the signal is stored in memory and sent to the D/A converter (or pulse width converter) 47, where it is converted to the original analog signal (or pulse width modulation signal), which is amplified and sent to the cathode ray tube. is applied to the modulation electrode (G1). This line memory circuit is used for time axis conversion, and its specific description will be explained using the signal waveform shown in the figure.

The number of beams used to scan the effective screen area (
In other words, the number of cathodes) in, the area horizontally scanned by each beam is 2 triplets (1 triplet is R, G, B).
(referring to one set of phosphor stripes), the video signal insertion time T f of each of the R, G, and B primary color signals 41 during a certain 1H period is
If the phosphor stripes on the phosphor surface are arranged in R-G-B, then Each primary color signal extended to 1 hour is gated with a gate pulse of T/6 time width to generate a time series signal 48 called ER-EG-EB.
and is input to a predetermined G1 electrode.

When attempting to display a faithful color image in a flat cathode ray tube that displays a full color screen through vertical scanning, the beam modulation described above, and horizontal scanning, it is necessary to A corresponding color modulation signal should be applied to the G1 electrode, but this fungus removal tube does not have this function, and the hue changes when the horizontal deflection width changes. If the intervals between the horizontal deflection electrodes are not uniform, each horizontal block will have a different color image in hue.

Purpose of the Invention The present invention solves the above-mentioned problems, and an object thereof is to provide a color image display device that eliminates color unevenness caused by horizontal landing variations and enables faithful color image display. It is something to do.

Structure of the Invention In order to achieve the above object, the present invention provides the following for each beam:
The arrival position on the phosphor surface is detected and memorized, and based on this memorized arrival position signal, the video signal applied to the G1 electrode is switched, and the color phosphor to which the beam is incident and should emit light is switched. This is a color image display device in which a color signal corresponding to the iG1 electrode is applied to the iG1 electrode.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In the present invention, when the flat cathode ray tube is manufactured and a predetermined voltage is applied to each electrode, first, only one water block is connected to G1.
A constant voltage is applied to the electrodes to emit a beam and scan the fluorescent surface. In this state, R or G''!The idea is to pass through the entire B filter and receive the R, G, or B light on the fluorescent surface with a photoelectric conversion element such as a photodiode, so that the beam starts horizontal scanning. The time required to scan each R, G, or B phosphor is detected.The signal from the photoelectric conversion element obtained in this way is input to the memory circuit and stored.The above is done over one field. When the above signal storage in one horizontal block is completed, the same operation is performed for the next horizontal block, and each R1 is a G or B fluorescent bar from the start of horizontal scanning for each horizontal block. A signal corresponding to the time until scanning is stored.

Next, when displaying a color image, the stored specific volume horizontal block signals are simultaneously read out in synchronization with each horizontal scan, and the color signal applied to the G1 modulation electrode is adjusted based on the read signals. This is done by switching the timing.

FIG. 5 shows a first embodiment of the present invention. 51 is a flat cathode ray tube that has been manufactured, and the internal electrode configuration is the same as the first one.
Since they are the same as those in Figures 3 to 3, they are omitted. Now, among the plurality of horizontal blocks of the flat cathode ray tube 61, a predetermined voltage is applied to each electrode so that the electron beam scans the fluorescent surface of only one horizontal block with diagonal lines. An enlarged view of a horizontal section of the fluorescent surface is shown in FIG. The fluorescent surface is R2G, B on the inner surface of the vacuum container of the transparent glass plate 61.
The three primary color phosphor stripes 62 are sequentially repeated in the horizontal direction via a light-blocking plaque stripe 63, and a metal back electrode 64 made of aluminum or the like is formed thereon. Here, the trio (R
, G, B (one set of phosphor stripes) f! :m, and each horizontal scan is R→G-B→R as shown by arrow A in Figure 6.
. . . -G-B is assumed to be scanned. At this time, the horizontal deflection amplitude is slightly increased to start scanning from a position where the H phosphor of the adjacent horizontal block is not scanned, and the photo is passed through the filter 62 that allows only the light of the wavelength from the R phosphor to pass through. By receiving the electron beam with a photoelectric conversion element 53 such as a diode, a timing signal when the electron beam scans the H phosphor is obtained. This is shown in FIG. Arrow B
is the horizontal scanning width, and 71 is a signal waveform obtained by extracting only the fundamental frequency component of the output from the photoelectric conversion element 53. By passing this through a limiter circuit, a signal waveform 72 is obtained. The above bandpass filter and limiter circuit is shown as a waveform shaping circuit at 64 in FIG. Here, the signal 72 has a time delay of J r p from the time when the beam scans the center of the phosphor due to the rise characteristics of the light emission of the phosphor and the delay characteristics of the waveform shaping circuit. This signal 7
2 is input to the memory circuit 55. The memory circuit 55 receives the horizontal synchronization pulse generated by the synchronization separation circuit 56 or the horizontal blanking pulse 7 generated based on the horizontal synchronization pulse.
3, a reference signal 74 is generated which is higher than the frequency fP of the output cuff 2 of the waveform shaping circuit and lower than fH (fH; horizontal scanning frequency). Time 11 until the rise or fall of the input signal 72 from the waveform shaping circuit 64;
12,13. ...Measure tnwo and store it in memory. Here, the reference signal 73 is adjusted in terms of memory capacity and the time up to the start of phase compensation, which will be described later. At this time, it goes without saying that the signals from each horizontal scan are stored in memory in synchronization with the vertical scan. As described above, the R timing signal obtained by horizontal scanning of each beam of one horizontal block can be stored in memory.

The same process is performed for the other horizontal blocks, and the timing signal for the beam scanning over the H phosphor on the entire screen of the flat cathode ray tube is memorized. The memory element used in the memory circuit 55 is a non-volatile one.

When the above operations are completed, the portion within the dotted line frame in FIG. 5, that is, the filter 52. The photoelectric conversion element 53 and the waveform circuit 54 are removed, and the operation moves on to actually display a color image.

When a color image is displayed on the flat cathode ray tube 61, the signals from the sync separation circuit 56 are used to simultaneously read out the stored signals corresponding to the corresponding horizontal scanning positions of each horizontal block. Here, one horizontal block among them will be explained.

A read reference signal 75 having the same frequency as the reference signal 74 generated when writing to the memory is used as a horizontal synchronization signal 73.
occurs in synchronization with. The time t0 from the rising edge of the horizontal synchronizing signal 73 to the start of the reading reference signal 76 at this time
' is t o ' (t o, and the time 11.12...-1 from the falling edge of this signal 76 is
After n, a signal 7e of a predetermined width is generated and input to the three-phase pulse generator 57.

Here, the start time t(:)' of the read reference signal 76 is t. The reason for making it smaller is to compensate for the delay time in the signal processing circuit after reading until the signal is applied to the modulation electrode of the flat cathode ray tube 61. The three-phase pulse generator 67 generates a signal having the same frequency as the input signal 72 to the memory circuit 66 and having a phase different from each other by 1200, which corresponds to the second line memory 46 explained in FIG. 4 above. By using it as a read signal from the line memory 58, R-G-B-R, --...
...and a time-series point-sequential signal is obtained. The signal obtained from this second line memory 68 is
An A converter 69 (or pulse width converter) converts the analog signal into a sum, which is amplified by an amplifier 60 and applied to the modulation electrode of the flat cathode ray tube 51. Here, as an example, 77 shows a signal applied to the modulation electrode when only R is displayed.

In the embodiment described above, a predetermined voltage is applied to a flat cathode ray tube that has been manufactured, and the fluorescent surface is scanned with an electron beam.
Each beam stores R, G, or B, and when displaying an actual color image, the stored timing signal is read out and the color video signal to be applied to the flat cathode ray tube is generated based on this signal. Color image display is performed by controlling according to the position of the fluorescent surface of the beam.

Next, a second embodiment of the present invention will be described. FIG. 8 shows a flat cathode ray tube used in the second embodiment of the present invention, FIG. 8 (A) is an external view of the flat cathode ray tube, and FIG. It is.

In the area for displaying a color image, three primary color phosphor stripes 82 of R, G, and B are sequentially repeated in the horizontal direction with black stripes 84 interposed therebetween, as in FIG. 6 above. Furthermore, an index phosphor 83 is formed outside the effective screen for displaying the color image. Here, the number of index phosphors is sufficient for at least one horizontal block, and the number of index phosphors is equal to or greater than the number of trios of color phosphors included in one horizontal block. FIG. 8B shows one practical example of this, in which four index phosphors 83 are provided corresponding to the G phosphor positions for one horizontal blur. The index phosphor 83 is R,
Either G or B may be used, but R or G, such as near-ultraviolet P-16.

BIl light bodies with different emission wavelengths? May be used.

Index phosphor 8 of the flat cathode ray tube 81 described above
A vertical cross-sectional view of the electrode structure of one horizontal block formed with No. 3 is shown in FIG. The electrode structure is the same as that shown in FIG. 1 and FIG.
Only 3 is different. That is, the linear cathode 9o is connected to at least one support 8 within the effective screen area 90-a and outside 90-b.
6, and the G1 electrode 93 is separated by 9 within the effective screen.
It is electrically separated into an outer part 3-a and an outer part 93-b. A filter 88 and a photoelectric conversion element 89 are attached to the outside of the vacuum envelope of the face glass 87 in correspondence with the index phosphor 83 to allow light having the emission wavelength of the index phosphor 83 to pass therethrough.

5) The filter 88 does not necessarily need to be attached, and the cand 90 does not need to be separated by a support.

A method of driving the flat cathode ray tube 81 described above will be described below. FIG. 10 shows the main system of the drive circuit, and FIG. 11 shows signal waveforms. The same parts as those in the driving method shown in FIG. 5 explained in the first embodiment are given the same numbers.

This embodiment also basically operates in the same manner as the first embodiment, in which only one of the plurality of horizontal blocks of the flat cathode ray tube 101 is scanned by the fluorescent surface with the electron beam. At this time, Figure 8.

The index phosphor section described in FIG. 9 is also driven so that the beam scans at the same time. FIG. 11 shows a color display section 11 consisting of an index phosphor section 111 and three primary color phosphors.
The relative positional relationship with 2 is shown.

In this embodiment as well, the beam is deflected wider than one horizontal block width 113. In this way, the beam scans the color phosphor of the color display section 112 from left to right in FIG. An output signal 116 is obtained by the waveform shaping section 64.

On the other hand, the index phosphor section 111 is also beam-scanned and the photoelectric conversion element 89. The signal 11 is generated by the waveform shaping section 102.
6, and this signal 116 is used as a reference signal in this embodiment. Thus, the time from the fall of reference signal 115 to the rise of signal 116 from the color display section (τ+
t ), (τ+t2) may be stored in the memory circuit 65, but as will be described later, the delay time from when the signal is read from the memory circuit to when the signal is applied to the flat cathode ray tube 101. To compensate for this, memory 55
A predetermined time τ from the fall of the reference signal 115 when inputting to
The time t1. from the time of delay to the rise of the signal 116 on the color display section. Store t2. This also reduces the capacity of the memory element.

The above-mentioned signal writing to the memory circuit 55 is performed for each horizontal block, and the timing signal of the beam that scans the R phosphors of all the images is stored using the signal from the index phosphor section as a reference. can. L/The index phosphor section is therefore always beam-scanned no matter which horizontal block is in operation.

Next, the process moves to displaying a color image. At this time the 10th
The portion within the dotted line frame in the figure is no longer necessary. The index phosphor section 111 is constantly beam-scanned, and a reference signal 116 is obtained from the waveform shaping section 102, which serves as a reading reference. Therefore, from the falling edge of the reference signal 115, 11.1
After 2 elapses, a signal 117 of a predetermined width is generated and inputted to the three-phase pulse generator 57.
The signals shown at 19 and 120 are generated. Since the subsequent signal processing system is the same as that of the first embodiment shown in FIG. 5, the explanation will be omitted.

The difference between the second embodiment described above and the first embodiment is in how the reference signal for writing and reading into the memory circuit is generated. In the first embodiment, the reference signal is generated based on the horizontal synchronization signal. In the second embodiment, the index is set outside the effective screen.Effects of the Invention The present invention applies a full predetermined voltage so that each beam scans the fluorescent surface, and each beam has a predetermined index. Detects and stores the timing signal for scanning the position of the light body, and controls the timing of the video signal applied to the modulation electrode of the flat cathode ray tube based on the stored signal in accordance with the position of the fluorescent surface of the beam. Therefore, even if slight errors occur during assembly when manufacturing a flat plate cathode ray tube, resulting in variations in the horizontal deflection width of each beam and the horizontal landing position, It is possible to display faithful color images without color unevenness.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of a flat cathode ray tube, a dynamic circuit system and an operating waveform diagram, FIG.
The figure shows a partially enlarged view, a perspective view and an internal front view of a flat plate cathode ray tube in operation, Figure 9 is a vertical sectional view of Figure 8, Figure 10 is a system diagram of its drive circuit, and Figure 11 shows each circuit. FIG. 10.90... Linear cathode, 12,92...
...Vertical scanning electrode, 13,93...G1
Modulation electrode, 14.94...G2 electrode, 15,9
5...G3 electrode, 16, 96...-G4 electrode, 17, 97...--Horizontal focus electrode, 18
, 98...horizontal deflection electrode, 43...
A/D converter, 44... Timing pulse generator, 76... First line memory, 76
...Second line memory, Ate...D
/A compa-p-, 52... Color filter, 5
3...Photoelectric conversion element, 54...Waveform shaping unit, 55...Memory, 66...Sync separator, 57...Three Phase pulse generator, 68・
...2nd line memory, 59...D/
A converter, eo-...+'1 ARs a
3... Index fluorescent material, 88...
Color filter, 89...Photoelectric conversion element, 1o2
... Waveform shaping section. Name of agent: Patent attorney Toshio Nakao and one other person
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−++ +−+12sf2γ −+ ++−+−+
+J L+++ (b) Figure 4 (b) Figure 5 Figure 8 Figure 9 Figure 10 Figure 11 (f2 scale RQBR
Q β ゛ ゛ G Bi12
'.

Claims (6)

[Claims] (1) A timing signal for a beam to scan a predetermined position on a phosphor surface in which at least three primary color phosphors of red, green, and blue are repeatedly and sequentially arranged in a horizontal direction through a black area is memorized. A flat cathode ray tube characterized in that a color image is displayed by reading out a timing signal and controlling a color video signal applied to the flat cathode ray tube based on this signal in accordance with the position of the phosphor surface of the beam. driving method. (2) By placing a photoelectric conversion element with a red, green, or blue filter on the front surface of a flat cathode ray tube whose fluorescent surface is scanned with a fixed amount of beam by applying a predetermined voltage, 2. The method of driving a flat cathode ray tube according to claim 1, further comprising detecting a timing signal when the beam scans each red, green, or blue position on the light surface. (3) Based on the television synchronization signal, generate a reference signal with a frequency higher than the fundamental frequency of the timing signal and whose difference is lower than the horizontal scanning frequency, store the phase difference between the reference signal and the timing signal, and 2. The method of driving a flat cathode ray tube according to claim 1, wherein the original timing signal is reproduced from the phase difference signal stored based on the reference signal. (4) A method for driving a flat cathode ray tube according to claim 3, wherein delay characteristics of the drive circuit system are compensated for by changing the phase of the reference signal. (5) Applying an index phosphor outside the effective display screen area, and scanning the phosphor section in synchronization with a beam that always scans the effective display screen area, thereby reducing the light from the phosphor section. A reference signal is generated by being received by a photoelectric conversion element, a phase difference between the reference signal and the timing signal is stored, and the original timing signal is reproduced from the stored phase difference signal based on the reference signal. A method for driving a flat cathode ray tube according to claim 1. (6) A patent claim characterized in that a screen is divided into blocks for display using a plurality of electron beam sources, and the position of the fluorescent surface is individually controlled for each electron beam in each block. A method for driving a flat cathode ray tube according to item 1.