JP3010626B2 - Adjustment method of image display device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generates an electron beam for each section when a screen on a screen is divided into a plurality of sections in the vertical and horizontal directions. The present invention relates to a method for adjusting a device for displaying a plurality of lines by deflecting an electron beam in a vertical direction and a horizontal direction and displaying a television image as a whole.

2. Description of the Related Art First, one basic configuration of an image display element used here will be described with reference to FIG.

The display element includes a rear electrode 1, a linear cathode 2 as a beam source, a beam extraction electrode 3, a beam flow control electrode 4, a focusing electrode 5, a horizontal deflection electrode 6, a vertical deflection electrode 7, and a screen in order from the rear to the front. Plates 8 are arranged and configured, and these are housed inside a flat vacuum vessel (not shown).

The linear cathode 2 as a beam source is stretched in a horizontal direction so as to generate an electron beam distributed linearly in a horizontal direction, and a plurality of such linear cathodes 2 (here, a plurality of linear cathodes) are provided at appropriate intervals. In the figure, only 7 lines 2 to 2 are shown). In this embodiment, it is assumed that the distance between the line cathodes is 3 mm, and the number of the line cathodes is 30.
We assume two. The distance between the linear cathodes 2 is not allowed to be freely large, and is regulated by the distance between a vertical deflection electrode 7 and a screen 8 described later. These line cathodes 2 are configured by coating an oxide cathode material on the surface of, for example, a tungsten wire of 10 to 30 μmφ. Then, as will be described later, control is performed such that the electron beam is emitted from the upper linear cathode 2 a in order for a predetermined time. The back electrode 1 suppresses the generation of an electron beam from another linear cathode 2 other than the linear cathode 2 controlled to emit the electron beam for a certain period of time, and directs the generated electron beam only in the forward direction. And push it out. This back electrode 1 may be configured using the inner surface of the rear wall of the vacuum vessel.

The beam extraction electrode 3 is a conductive plate 11 having a plurality of through holes 10 provided at predetermined intervals in the horizontal direction facing each of the linear cathodes 2a and 2b. It is taken out through the through hole 10.

Next, the control electrode 4 has a vertically long conductive plate 15 having a through-hole 14 at a position facing each of the linear cathodes 2a to 2b, and a plurality of the control electrodes 4 are arranged side by side in a horizontal direction at a predetermined interval. Have been. In this embodiment, 120 control electrode conductive plates 15a to 15n are provided (only eight are shown in the figure). The control electrode 4 controls the passing amount of each of the electron beams divided in the horizontal direction by the beam extraction electrode 3 according to a video signal for displaying each picture element. One line of video is displayed on the 120 control electrodes 4 at a time.

The focusing electrode 5 is a conductive plate 17 having a through hole 16 at a position facing each through hole 14 provided in the control electrode 4, and focuses an electron beam passing through the through hole 14 provided in the control electrode 4. .

A plurality of horizontal deflection electrodes 6 are vertically arranged at positions on both sides of the through hole 16.
A horizontal deflection voltage is applied to each of the electrodes 18 and 18 ′ to deflect the electron beam for each picture element in the horizontal direction, and the R, G, and B phosphors on the screen 8. Are sequentially irradiated to emit light. The deflection range is
In this embodiment, each electron beam has a width of two picture elements.

The vertical deflection electrode 7 has a plurality of conductive plates 19 and 19 ′ arranged in the horizontal direction at intermediate positions of the respective through holes 16.
, And a voltage for vertical deflection is applied to each of the electrodes 19, 19 'to deflect the electron beam in the vertical direction.
In this embodiment, an electron beam generated from one linear cathode is deflected by a pair of electrodes 19 and 19 'to a position corresponding to eight lines in the vertical direction. And by the 31 vertical deflection electrodes 7,
Thirty conductor pairs corresponding to each of the thirty linear cathodes are formed, and eventually deflect the electron beam so as to draw 240 horizontal lines on the screen 8. The electron beam is bent mainly in the space between the horizontal and vertical deflection electrodes 6, 7 and the screen 8, but the entire screen is configured with a sufficiently small deflection amount compared to the distance of this space so that large deflection distortion does not occur. The screen is divided so that it can be performed.

The screen 8 is configured such that a phosphor 20 that emits light when irradiated with an electron beam is applied to the back surface of a glass plate 21 and, if necessary, a metal back layer (not shown) is added. The phosphor 20 is provided with two pairs of phosphors of three colors R, G, and B for one slit 14 of the control electrode 4, that is, for each one electron beam divided in the horizontal direction. And are applied in stripes in the vertical direction. In FIG. 3, dashed lines drawn on the screen 8 indicate vertical divisions displayed corresponding to the plurality of line cathodes 2, and two-dot chain lines correspond to the plurality of control electrodes 4, respectively. Indicates the horizontal division displayed as. As shown in an enlarged view in FIG. 4, the two partitions R, G, and B phosphors of two pixels in the horizontal direction
And has a width of eight lines in the vertical direction. 1
The size of one section is, for example, 1 mm in the horizontal direction and 3 mm in the vertical direction. The phosphors of the three colors R, G, and B may be applied in an arrangement other than the vertical stripes, for example, in a delta arrangement.

It should be noted that, in FIG. 3, the length in the horizontal direction is drawn to be approximately twice as large as that in the vertical direction for easy understanding.

In this embodiment, two pairs of R, G, and B phosphors 20 for two picture elements are provided for one control electrode 4, that is, one electron beam. Alternatively, three or more picture elements may be provided, in which case the control electrode 4
R, G, B video signals for one picture element or more than three picture elements are sequentially added, and a horizontal deflection is made in synchronization with the picture signals.
Further, the phosphors of the three colors R, G, and B may be applied in an arrangement other than the vertical stripe, for example, in a delta arrangement.
In that case, horizontal and vertical deflection voltages suitable for the phosphor arrangement are applied.

Next, a basic configuration of a drive circuit for displaying an image on the display element will be described with reference to FIG. First, a driving portion for irradiating the screen 8 with an electron beam to emit a raster will be described.

The power supply circuit 22 is a circuit for applying a predetermined bias voltage (operating voltage) to each electrode of the display element.
DC voltage V1 is applied to the beam extraction electrode 3, V3 is applied to the focusing electrode 5, and V8 is applied to the screen 8.

The line-cathode drive circuit 26 generates a line-cathode drive pulse [I-ma] using the vertical synchronizing signal V and the horizontal synchronizing signal H. FIG. 6 shows the relationship between the vertical synchronizing signal V, the horizontal synchronizing signal H, and the line cathode drive pulse [i-ma]. Each of the line cathodes 2a to 2m is heated by applying a current during the high potential of the drive pulse [i to ma] so that electrons can be emitted during the low potential period of the drive pulse [a to ma]. The heating state is maintained. As a result, electrons are emitted from the 30 line cathodes 2a to 2m only during the 8H period in which a low-potential drive pulse [a to m] is applied. During the period in which the high potential is applied, the potential is applied to the line cathodes 2a to 2b higher than the potential at the position of the line cathode 2 determined by the bias voltage applied to the back electrode 1 and the beam extraction electrode 3. Since the high potential is positive, no electrons are emitted from the linear cathodes 2a to 2m. Thus, in the linear cathode 2, during the effective vertical scanning period, the lower linear cathode 2
Electrons are emitted toward the mask in order for 8H periods.

The deflection voltage waveform generation circuit 40 includes a direct memory access controller (hereinafter, DMA controller) 41, a memory for storing deflection voltage waveform (hereinafter, deflection memory) 42, and a digital-analog converter (hereinafter, D / A converter) 43h, 43v. Then, a vertical deflection signal v, v 'and a horizontal deflection signal h, h' are generated. In this embodiment, the vertical deflection signal is 240H
There are two sets of memory address areas for storing the vertical deflection signals corresponding to the respective lines, and by storing regular data in the memory every 8H, two fields of vertical deflection signals of eight stages are obtained. be able to.
For horizontal deflection signals, 1H
Since it is necessary to horizontally deflect the electron beam in six stages during the period, there are six memory address areas corresponding to each horizontal deflection waveform of 1 during 1H and 240H x 6 / H = 1440 during 1V. By storing data having regularity in the memory every 1H, a horizontal deflection signal of a six-step wave can be obtained.

As described above, one of the line cathodes 2a to 2 to which a low-potential drive pulse is applied during the effective scanning period (the period of 240H in this case) excluding the vertical blanking period in the vertical cycle. The electron beam emitted from the linear cathode is divided into 120 sections in the horizontal direction by the beam extraction electrode 3 and extracted as a row of 120 electron beams. The passing amount of the electron beam is controlled by the control electrode 4 for each section as described later, and after being focused by the focusing electrode 5, a pair of horizontal deflection signals h changing in six stages as shown in FIG. ,
The h 'the horizontal deflection electrodes 18, 18 made', each of _{R 1, G 1, B 1} , R 2, G 2, B 2 ( control electrode 5 of the screen 8 during each horizontal period 15a~15h The phosphor corresponding to is R for two picture elements,
G, B, but for convenience of explanation, one picture element is R ₁ , G ₁ , B ₁ ,
The other is R ₂ , G ₂ , and B ₂ ), and the phosphors are sequentially irradiated with H / 6. Thus, in the raster of each line, the electron beams are sequentially irradiated on the respective phosphors 20 of R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , and B ₂ for each of the 120 sections in the horizontal direction. Therefore, by the electron beam for each horizontal segment of each line is modulated by _{R 1, G 1, B 1} , R 2, G 2, B 2 of the video signal, displaying a color image on the screen 8 Can be.

 Next, the modulation control portion of the electron beam will be described.

First, R, G, and B primary color signals (hereinafter, referred to as R, G, and B video signals) applied to the signal input terminals 23R, 23G, and 23B are applied to 120 sample and hold circuit sets 31a to 31n. . Each sample and hold circuit set 31a to 31n is for R1, G1, B1
, R2, G2, and B2. The sampling pulse generation circuit 34 performs an effective horizontal scanning period (approximately 50 μsec) of the horizontal cycle (63.5 μsec).
In addition, 120 × 6 = 720 sampling pulses Ra corresponding to the sample hold circuits for R1, G1, B1, R2, G2, and B2 of the 120 sample hold circuit groups 31a to 31n, respectively.
_{1 to} Bn ₂ are sequentially generated. Each of the 720 sampling pulses Ra _{1 to} Bn ₂ has 120 sample-hold circuit groups 3
6 are added to 1a to 31n, so that each sample and hold circuit group has R1, G1, B1, R2, G2, and B2 images corresponding to two picture elements when one line is divided into 120 lines. The signals are individually sampled and held. The sampled and held 120 sets of R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , and B ₂ video signals are simultaneously transmitted to the 120 sets of memories 32 a to 32 n by the transfer pulse t after one line of sample and hold is completed. , Where it is held for the next horizontal period. R ₁ The _{held, G 1, B 1, R} 2, G 2, B 2 of the signal is applied to 120 of the switching circuit 35a-35n. The switching circuit 35a~35n intended each of which is constituted by a circuit having a _{R 1, G 1, B 1} , R 2, G 2, the common output terminal B ₂ of the individual input terminals and sequentially switching them to output is there. Each switching circuit 35a-3
5n is synchronously switched and controlled by switching pulses r ₁ , g ₁ , b ₁ , r ₂ , g ₂ , b ₂ applied from the switching pulse generating circuit 36. Switching pulse r ₁ , g ₁ , b ₁ , r ₂ , g ₂ , b
₂ is H / 6 switching circuit by dividing each horizontal period into 6
Switched _{35a~35n, R 1, G 1,} B 1, R 2, G 2, is divided at each picture signal of B ₂ sequentially outputs the switching signal to supply the pulse width modulation circuit 37a~37n Generate r ₁ , g ₁ , b ₁ , r ₂ , g ₂ , b ₂ .

The output of the switching circuit 35a~35n is added to 120 pairs of pulse-width modulation (PWM) circuit 37A～39n, wherein, R ₁ that is sampled and _{held, G 1, B 1, R} 2, G 2, B ₍₂₎ Pulse width modulation is performed according to the magnitude of the video signal and output. The outputs of the pulse width modulation circuits 37a to 37n are individually applied as display elements to the 120 conductive plates 15a to 15n of the control electrode 4 as control signals for modulating the electron beam.

It should be noted here that the switching circuits 35a to 35n
Supply switching of the video signals of R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , B _{2 at} , and the electron beams R ₁ , G ₁ , B ₁ , R ₂ , by the horizontal deflection drive circuit 41
Synchronous control is performed such that the switching of the irradiation of the phosphors G ₂ and B ₂ to the horizontal deflection is completely the same in timing and order. Thus, the when the electron beam is irradiated to the R ₁ phosphor dose of the electron beam is controlled by the R ₁ video _{signal, G 1, B 1, R} 2, G 2, B 2
Is controlled in the same way, and R ₁ , G ₁ , B ₁ , R ₂ ,
G _2, B ₂ will be light emission of each phosphor are controlled by the _{R 1, G 1, B 1} , R 2, G 2, B 2 of the video signal of the picture element, each picture element of the input Light emission is displayed according to the video signal.
This control is performed simultaneously for 120 sets of one line (each of two picture elements) to display an image of 240 picture elements per line. Further, for 240 lines, the picture is sequentially executed from the upper line. Will be displayed.

The above operations are repeated for each field of the input video signal, and as a result, an image of a moving image is displayed on the screen 8 in the same manner as a normal television receiver.

A clock required for controlling the image display device is supplied from a pulse generation circuit 39 whose timing is controlled by a horizontal synchronization signal H and a vertical synchronization signal V.

Problems to be Solved by the Invention The image display element as described above, unlike the shadow mask method, needs to accurately irradiate the R, G, B phosphors on the screen with the electron beam, and therefore, the horizontal deflection of the electron beam It is necessary to accurately adjust the voltage for each image display element. Conventionally, since the above adjustment was performed visually, an adjustment time of about one hour was required for each unit.

SUMMARY OF THE INVENTION The present invention solves the above problems, and provides an adjustment method that can easily and accurately adjust the horizontal deflection voltage in such an image display device and can easily shift to automation. It is assumed that.

Means for Solving the Problems In order to solve the above problems, the present invention can have means for measuring and detecting the brightness and color of a screen, for example, a light receiving element with a filter, an A / D converter, a memory, etc. For each of all the horizontal deflection voltages, find the horizontal deflection voltage at which the electron beam irradiates the center of the phosphor for each scanning line,
Based on the result, a controller for changing the horizontal deflection voltage of the image display element and the entire system are controlled to adjust the horizontal deflection voltage waveform.

Operation In such a configuration, first, a light receiving element with a filter or the like is attached to a portion to be adjusted on the screen, and each measurement output of the light receiving element is A / D converted and stored in a memory. Then, for each scanning line, the output of the light-receiving element with a filter and the horizontal deflection voltage at that time are stored for all possible values of the horizontal deflection voltage. Next, the horizontal deflection voltage when the output of the light-receiving element of each color is maximized is obtained using a CPU or the like, and a horizontal deflection voltage for accurately irradiating the phosphor of each color to each scanning line is created. I do.

By performing the above operation independently for each scanning line, an accurate horizontal deflection voltage waveform can be created for the entire screen, and the adjustment is completed.

Embodiment An embodiment of the present invention will be described with reference to FIG.

50 is an image display device to be adjusted, 56 and 51 are light receiving elements and amplifiers with R, G, B filters, 52 is an A / D converter, 53 is a memory, 54 is a controller, and 55 is a CPU.

For illustration, the horizontal deflection voltage of the image display device 50 and is capable of 256 kinds of the voltage V ₀ ~V _255.

First, the controller 54 fixes the horizontal deflection voltage of the image display device 50 to V _0. In this state, the image display device draws a raster, and the output of the light receiving element 56 of each color for each scanning line is stored in the memory 53. If the number of scanning lines is 240, the data amount is 240 × 3, and the required time is 1/60 second.
Then, repeating the fixed same operation a horizontal deflection voltage V _1. Repeated to the horizontal deflection voltage the operation is V _255. The total data amount is 240 × 3 × 255, and the required time is 1 /
60 x 2554.3 seconds.

Next, a method of creating horizontal deflection data based on 240 × 3 × 255 data will be described with reference to FIG.

With one scanning line fixed and the horizontal deflection voltage as a variable, R,
When the output of each of the light receiving elements with the G and B filters is graphed, the output becomes f _R , f _G , and f _B in FIG.

Here, FIG. 2 is a drawing of data for one scanning line, and each graph is drawn as a continuous function, but each data is actually 255 data. Only × 255 data is drawn. In the image display element used in the present invention, as described above,
The electron beam passing through the through hole 16 provided in the focusing electrode 5 is subjected to R, G, B,
It is deflected by the width of two picture elements of R, G and B. Each electron beam at this time the horizontal deflection voltage and toward the V ₂₅₅ increases monotonically from V ₀ is R on the screen, G, B, R, will move G, and B. At this time, assuming that the horizontally arranged electron beams move in the same phase, when the emission intensity of each color is maximized, the electron beam irradiates the center of the stripe-shaped phosphor of each color. Therefore, as shown in FIG. 2, the horizontal deflection voltage that gives a maximum to each of f _R , f _G , and f _B is V _R1 ,
V _G1 , V _B1 , V _R2 , V _G2 , V _B2 , V _R1 , V _G1 , V _B1 ,
The voltage waveform h connected in a staircase in the order of V _R2 , V _G2 , and V _{B2 is} the horizontal deflection voltage waveform necessary to draw the scanning line specified above. That is, from the 3 × 255 data corresponding to one scanning line, six data necessary for producing a horizontal deflection waveform of the scanning line are extracted, and at this time, the electron beam forming the scanning line is a stripe of each color. The center of the phosphor is illuminated.

The adjustment for the horizontal deflection is completed by calculating the horizontal deflection voltage waveform in the same manner for all the 240 scanning lines. The above data operations can be performed using the CPU 55.

Effect of the Invention As described above, according to the present invention, the horizontal deflection voltage is adjusted by selecting the horizontal deflection voltage at which the electron beam irradiates the center of the striped phosphor for each scanning line and adjusting the deflection waveform. It can be done automatically, quickly and accurately.

[Brief description of the drawings]

FIG. 1 is a conceptual block diagram of a system for realizing an image display device adjusting method according to an embodiment of the present invention, FIG. 2 is a waveform diagram for explaining the operation thereof, and FIG. 3 is a diagram of an image display element used in the present invention. FIG. 4 is an enlarged front view of a fluorescent screen of the image display device, FIG. 5 is a block diagram of a drive circuit of the image display device, and FIG. 6 is a waveform diagram for explaining the operation of the drive circuit. is there. 50: Image display device, 51: Amplifier, 52: A / D converter, 53: Memory, 54: Controller, 55: CPU, 5
6 ... Light receiving element.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/68 B H04N 9/28 Z H04N 3/16 C H01J 9/44 B

Claims (1)

(57) [Claims] A linear cathode is provided for each vertical section obtained by dividing a screen on a screen into a plurality of sections in a vertical direction, and an electron beam generated from the linear cathode is deflected in a vertical and horizontal direction on a screen. In an image display device for forming a color image coated in a stripe shape in the vertical direction, when adjusting the horizontal deflection voltage waveform, means for measuring the hue and luminance of all the scanning lines, and Means for generating a horizontal deflection voltage for each of the possible horizontal deflection voltages, for each of the possible horizontal deflection voltages, the hue and luminance of all scan lines are measured independently, and for each scan line the electron beam is applied to each phosphor. A method of adjusting an image display device, wherein a horizontal deflection waveform is created by finding a horizontal deflection voltage for irradiating the center.