JP2926738B2 - Deflection circuit for large screen display element - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection circuit used for a display element (a so-called display cell) included in a large-screen display device.

[Summary of the Invention]

The present invention relates to a deflection circuit for a large-screen display element, in which a deflection waveform for traversing a self-luminous type picture element is a saw-tooth waveform, and a deflection waveform in the other direction is a step deflection waveform, so that display by tilt of a scanning line is performed. This prevents the fluctuation of the luminance and displays a good image as a whole.

[Conventional technology]

As a device for displaying a so-called television signal on a large screen, conventionally, a plurality of display devices such as a color cathode ray tube are vertically arranged,
There are known those which are assembled on the left and right to divide and display an image, and those which display a plurality of display elements of a single color or three primary colors in a matrix and display each picture element.

However, when these devices are used, in the former case, non-display portions such as the joints of the cathode ray tubes become black lines and are formed on the display surface, which hinders image viewing. In the latter case, there is a limit in miniaturizing the shape of the display element, and there is a drawback that the picture element becomes coarse and viewing from a close distance cannot be performed well.

[Problems to be solved by the invention]

On the other hand, the applicant of the present application has previously proposed a display element for a large screen which solves the above-mentioned disadvantages (Japanese Patent Application No. 63-331505).

That is, FIG. 6A is a side sectional view of the large-screen display element of the prior application, and FIG. 6B is a front view thereof. In the figure, (1)
Denotes a tube, which is a front panel made of glass (2)
And a funnel part (3) integral with the neck part.

The front panel (2) has a strip-shaped fluorescent display portion on its inner surface, which is a plurality of sets of picture elements, in this example, a total of 8 horizontal × 8 vertical.
64 sets of so-called phosphor trios (4) are formed.

The phosphor trio (4) has blue, red, and green light-emitting phosphor layers (B), (R), and (G) having a length L and a width W, as shown in the figure. It is arranged at a predetermined pitch (P) on the display surface (5) and its longitudinal direction is arranged along the horizontal direction. A light absorbing layer is formed on the surface other than the phosphor layers (B), (R), and (G).

The front panel (2) and the funnel (3) are joined to each other using frit glass. In this example, a step portion is provided on the inner peripheral surface side of the flat front panel (2), and the funnel portion (3) is joined so as to fit into the step portion. The outer peripheral surface of the portion of the funnel that is joined to the front panel is formed to be perpendicular to the surface of the front panel. The phosphor trio (4) may be formed by either a printing method or a slurry method.

As the electron gun (6), an electron gun that emits a single electron beam (e) is used. The electron beam is sequentially modulated by, for example, video signals of three primary colors by switching, and each of the blue phosphor layer (B), the red phosphor layer (R) and the green phosphor layer of the phosphor trio (4). Scanning is performed vertically and horizontally by the deflection yoke (7) as if tapping (G). The beam shape is desirably a horizontally long beam shape (for example, an oval shape) so as to correspond to the shape of the phosphor layer.

In this example, since the phosphor trio (4) is arranged along the X direction in the longitudinal direction in the electron beam scanning in this example, the phosphor layer (B) is scanned in the conventional scanning method, that is, while scanning horizontally. ), (R) and (G), instead of hitting them, the phosphor layers (B), (R),
(G) is hit.

By arranging a large number of display elements (8) having the above configuration in a two-dimensional manner as shown in FIG. 7, phosphors are provided between adjacent display elements (8) as shown in FIG. A large-screen display device (9) in which the pitch (P) of the trio (4) is constant is configured.

As a specific example, a large-screen display device (9) is configured by arranging a total of 1200 display elements (8) in the vertical direction and 40 in the horizontal direction, that is, a total of 1200 display elements.

Thus, a large-screen display device (9) is configured.
According to this device, by using the above-described display element (8), the shape of the picture element can be reduced, and viewing from a relatively short distance can be favorably performed, and the pitch of the picture element can be improved. Is constant and no black line or the like is formed by the non-display portion.

Further, by using the above-described display element (8), the range (angle) in which good viewing can be performed at an appropriate viewing distance can be expanded. That is, in the above-mentioned element (8), the front panel (2) exists before each of the phosphor layers (B), (R) and (G), so that the display surface ( 5) is equivalent to a frame having a height corresponding to the thickness of the panel (2).

In this case, if the phosphor trios are arranged so that the longitudinal direction runs along the vertical direction, as is often the case with conventional display elements of this type, the display is performed from an oblique direction as shown in FIG. 9A. when forceps surface (5), this when the angle theta ₁ is greater than a predetermined green fluorescent material layer end (G), or blue fluorescent material layer (B) is hidden by the frame, each green or blue Is attenuated, so that a streak whose hue is shifted to magenta or yellow is formed at each end.

On the other hand, if the longitudinal direction of the phosphor trio is arranged along the horizontal direction as described above, even if the image is viewed from an oblique direction as shown in FIG. Only a slight decrease in luminance does not cause a noticeable error such as a change in hue, and good viewing can be achieved over a wider range in the horizontal direction (angle θ ₂ ). In a normal use situation, the viewing direction does not spread in the vertical direction.

As described above, the display element (8) and the large-screen display device (9) using the same have various effective advantages.

However, in such a display element (8), the scanning of the electron beam described above is performed once in one field (horizontal (plane)).
Scanning and eight vertical (line) scans will be performed.
In that case, if those scans are performed with the same saw-tooth wave as in the conventional case as shown in FIG. 10, the number of line scans is as small as eight, so that the scan lines are affected by the surface scan and the scan lines in FIG. (7), the scanning line cannot pass through the center of all the phosphor layers (B), (R), and (G), and the brightness of the display may be uneven. there were. In the drawing, the solid line is the scanning period, and the broken line is the retrace period.

On the other hand, a deflection yoke for scanning can be provided at an angle so that the scanning line passes through the centers of all the phosphor layers as shown in FIG. In order to perform scanning in accordance with the shape of the surface (5), it is necessary to adjust the scanning width and position for each scanning line, and it is necessary to perform extremely complicated control.

This application is made in view of such a point, and aims at obtaining a favorable display with a simple configuration.

[Means for solving the problem]

According to the present invention, a plurality of strip-shaped self-luminous picture elements (phosphor trio (4)) are arranged on a display surface (5) of a tubular body (1) at predetermined pitches in one and the other directions orthogonal to each other. (P), and irradiating the strip-shaped self-luminous picture element with the electron beam while deflecting the electron beam in the one direction and the other direction, and traversing the strip-shaped self-luminous picture element. The deflection waveform (vertical deflection circuit (59V)) in the direction (1) is a sawtooth wave, and the deflection waveform (horizontal deflection circuit (59H)) in the other direction is changed in potential level every cycle of the sawtooth wave. A slope correction circuit (multiplexer (73), volume control (77)) that corrects the gradient of the potential level with respect to a time change in one cycle of the sawtooth wave of the potential level of the step deflection waveform as well as the step deflection waveform. )
Etc.) are provided for the large-screen display element deflection circuit.

[Action]

According to this, the inclination of the scanning line is eliminated by setting the deflection waveform in the other direction to a step deflection waveform, and the scanning line can be passed through the center of all the phosphor layers, and unevenness in luminance and the like can be obtained. No good display can be made.

〔Example〕

FIG. 1 shows the overall circuit configuration of the signal system. In this figure, a signal from an antenna (11) is supplied to a tuner (12) to receive a desired television signal, and the received signal is supplied to a detection circuit (13) to demodulate a composite video signal. This demodulated signal is supplied to one fixed contact of the input selection switch (14). The composite video signal supplied to the video input terminal (15) is supplied to the other fixed contact of the switch (14), and the signal selected by the switch (14) is supplied to the color demodulation circuit (16). Three primary color signals of blue (B), red (R) and green (G) are extracted.

On the other hand, the signal from the switch (14) is the sync separation circuit (17)
To separate the horizontal and vertical synchronization signals, and these synchronization signals are supplied to a timing control circuit (18). The control circuit (18) first forms a sampling signal Sp obtained by dividing the horizontal effective screen period into, for example, 320 equal parts, and this signal Sp is divided into three A / D converters (19B), (19R), and (19).
G) are commonly supplied.

The primary color signals from the color demodulation circuit (16) are supplied to the A / D converters (19B), (19R), and (19G).
Then, for example, an 8-bit digital signal A / D-converted at the timing of the above-mentioned signal Sp is supplied to the field memories (20B), (20R), and (20G).

Further, the above-mentioned signal Sp and the start signal Ss corresponding to the upper end of the effective screen from the control circuit (18) are supplied to the write address generation circuit (21), and the write address generated by this circuit (21) is It is supplied to the memories (20B), (20R), and (20G). Thus, during one field period of the video signal, for example, 320 × 240 (the number of horizontal scanning lines) = 76800 video signal data constituting the field are stored in the memories (20B), (20R), (20G) for each primary color. Is written to.

The memory (20B), (20R),
In response to (20G), an arbitrary clock signal from the above-described control circuit (18) is supplied to a read address generation circuit (22), and the read address generated by this circuit (22) is stored in the memories (20B), (20G). 20R) and (20G). As a result, the read video signal data is transferred to the data bus (23
B), (23R) and (23G). The generator (2
The address from 2) is supplied to the address bus (24).

And each bus (23B), (23R), (23G) and (24)
In contrast, the above-mentioned 1200 display elements (8 ₁ ), (8 ₂ ) ‥‥
(8 ₁₂₀₀₎ signal processing circuit provided in each (25 _1), (25
₂ ) ‥‥ (25 ₁₂₀₀ ) is connected.

FIG. 2 shows the structure of an arbitrary signal processing circuit (25). In this figure, buses (23B), (23R),
The data of (23G) and the address of the bus (24) are supplied to the memories (51B), (51R), and (51G) for 64 data each corresponding to one display element (8), and a part of the address. Is supplied to the decoder (52), and signals generated only at the address of necessary data are supplied to the memories (51B) and (5B).
1R) and (51G) are supplied to the enable terminal. As a result, the data of the 64 × 3 primary colors displayed on the corresponding display element (8) is written into the memories (51R), (51B) and (51G).

Further, the synchronization signal Sf corresponding to the vertical synchronization signal of the video signal from the above-described timing control circuit (18) is output to each processing circuit (2
5) Individual timing control circuit provided for each (53)
Supplied to

Then, the memories (51B), (5
For the 1R) and (51G), the control circuit (53) forms a timing signal St in which, for example, the interval of the vertical synchronization signal Sf is equally divided by 64, and this signal St is supplied to the read address generation circuit (54). The read address generated by the circuit (54) is supplied to the memories (51B), (51R) and (51G). Further, the signal St is commonly supplied to the three D / A converters (55B), (55R), and (55G), and the D / A converters (55B), (55R), (5
5G) are supplied with data read from the memories (51B), (51R), and (51G), respectively.

Thereby, from the D / A converters (55B), (55R), and (55G), 64 data are sequentially converted into analog data and taken out at each timing of the signal St. The reading order is sequentially read from top to bottom from the leftmost column of picture elements shown on the display surface (5), and this column is sequentially moved from left to right.

The signals from these D / A converters (55B), (55R), and (55G) are connected to the selection switches (56B), (56R), and (56
G). The display element (8) has a display surface (5).
Detector of index indicating the position of each phosphor layer above (5
7) is provided, and a signal from the detector (57) is supplied to the control circuit (53). The control circuit (53) generates selection signals Sb, Sr, Sg corresponding to the colors of the respective phosphor layers, and switches (56B), (56) are formed by these signals Sb, Sr, Sg.
R) and (56G) are controlled. These switches (56
B), (56R), (56G) selected signals are mixed,
It is supplied to the electron gun (6) of the display element (8) through the drive amplifier (58).

Further, a signal equivalent to the signal Sf and a signal Sl obtained by multiplying the signal Sf by 8 are formed from the control circuit (53), and the signal Sl is supplied to the vertical deflection circuit (59V) and synchronized with the signal Sl. A sawtooth wave is formed. This sawtooth wave is supplied to the vertical deflection coil of the deflection yoke (7) of the display element (8). Further, the signals Sf and Sl are supplied to the horizontal deflection circuit (59H) to form a step deflection waveform synchronized with the signals Sf and Sl, and the signal of this waveform is supplied to the horizontal deflection coil of the deflection yoke (7). .

FIG. 3 shows a specific configuration example of a horizontal deflection circuit (59H) for forming this step deflection waveform. In this figure, signals Sl and Sf as shown in FIGS. 4A and 4B are supplied to a signal generation circuit (71). The signal Sl is also supplied to the above-described vertical deflection circuit (59V). In this circuit (59V), a sawtooth wave as shown in FIG. C is formed and supplied to the vertical deflection coil of the deflection yoke (7). I have.

On the other hand, from the signal generating circuit (71) signals phi ₁ to [phi] _3, as shown in FIG D~F are generated, these signals phi ₁ to [phi] ₃
Is supplied to the multiplexers (72) and (73). The multiplexer (72) to the provided eight position potentiometer (74), the voltage of the volume selected by the signal phi ₁ to [phi] ₃ described above is removed from the multiplexer (72), through a buffer circuit (75) Pre-amplifier (76)
Supplied to

The multiplexer (73) to the provided eight tilt potentiometer (77), the voltage of the volume selected by the signal phi ₁ to [phi] ₃ described above is taken out from the multiplexer (73). The extracted voltage is supplied to an integrator (79) through a level adjustment circuit (78), and a signal
Sl is supplied to the reset means (81) of the integrator (79) through the buffer circuit (80), and the output of the integrator (79) is supplied to the preamplifier (76).

As a result, from the preamplifier (76), the height of the starting end of each step is determined by the volume (74) and the step whose slope is determined by the volume (77), as shown in FIG. The deflection waveform is output and the output circuit (82)
To the horizontal deflection coil (83) of the deflection yoke (7).

Therefore, according to this circuit, the inclination of the scanning line is removed by using the deflection waveform in the other direction as the step deflection waveform,
As shown in FIG. 5, it is possible to pass the scanning line to the center of all the phosphor layers, and it is possible to perform a good display without unevenness in luminance or the like.

It is appropriate to adjust the above volumes (74) and (77) by actually performing display on each display element (8) and visually checking the scanning lines.

At this time, by adjusting (correcting) the inclination of the scanning line, the fluctuation due to the fluctuation of each display element (8) can be eliminated.

〔The invention's effect〕

According to the present invention, the inclination of the scanning line is eliminated by setting the deflection waveform in the other direction to a step deflection waveform, and the scanning line can be passed through the center of all the phosphor layers, and uneven brightness and the like can be obtained. It is possible to perform a good display without any.

[Brief description of the drawings]

FIGS. 1 to 3 are circuit diagrams of an example of the present invention, FIGS.
The drawings are for the purpose of explanation, and FIGS. 6 to 11 are diagrams for explaining the previously proposed display element. (1) is a tube, (4) is a phosphor trio, (5) is a display surface, (59V) is a vertical deflection circuit, and (59H) is a horizontal deflection circuit.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-196978 (JP, A) JP-A-48-103129 (JP, A) JP-A-56-40545 (JP, A) JP-A-60-1985 59888 (JP, A) JP-A-57-135590 (JP, A) JP-B-39-8890 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04N 3/16 H04N 5 / 68

Claims (1)

(57) [Claims] A plurality of strip-shaped self-luminous picture elements are arranged on a display surface of a tubular body at a predetermined arrangement pitch in one direction and the other direction orthogonal to each other, respectively. On the other hand, when irradiating the electron beam while deflecting the electron beam in the one and other directions, the deflection waveform in the one direction crossing the strip-shaped self-luminous picture element is a sawtooth wave, and the deflection in the other direction is performed. The waveform is a step deflection waveform in which the potential level is changed for each cycle of the sawtooth wave, and the potential level is changed with respect to the time change of the potential level of the step deflection waveform in one cycle of the sawtooth wave. A deflection circuit for a large-screen display element, comprising a tilt correction circuit for correcting the tilt of the display.