JP2817149B2 - 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 a vertical direction, and generates an electron beam for each section. The present invention relates to an apparatus for displaying a plurality of lines by deflecting a beam in a vertical direction and displaying a television image as a whole.

2. Description of the Related Art Conventionally, a cathode ray tube is mainly used as a display element for displaying a color television image. However, a conventional cathode ray tube has a very long depth compared to a screen size, and is a thin television receiver. It was impossible to create. Recently, EL display devices, plasma display devices, liquid crystal display devices, and the like have been developed as flat display devices, but all of them are insufficient in performance such as luminance, contrast, and color display, and have been put to practical use. Has not been reached.

In order to achieve a flat display device using an electron beam, the present applicant has filed Japanese Patent Application No. 56-20618 (Japanese Unexamined Patent Application Publication No.
7-135590), a new display device was proposed.

This is because when the screen on the screen is vertically divided into multiple sections, an electron beam is generated for each section, and each line is deflected vertically for each section to display multiple lines Then, a television image is displayed as a whole.

First, one basic configuration of the image display element used here will be described with reference to FIG. The display element comprises a back electrode 1, a linear cathode 2 as a beam source, vertical focusing electrodes 3, 3 ', a vertical deflection electrode 4, a beam current control electrode 5, a horizontal focusing electrode 6, a horizontal A deflecting electrode 7, a beam accelerating electrode 8, and a screen 9 are arranged and configured, and these are housed in a evacuated flat glass bulb (not shown). The linear cathode 2 as a beam source is stretched in the horizontal direction so as to generate an electron beam distributed linearly in the horizontal direction, and a plurality of such linear cathodes 2 are vertically arranged at appropriate intervals (in FIG. (Only four of 2a to 2d are shown). In this example, it is assumed that 15 are provided. Let them be 2a-2yo. These line cathodes 2 are formed by coating a surface of a tungsten wire of, for example, 10 to 20 μφ with an oxide cathode material for emitting thermoelectrons. These linear cathodes 2a to 2yo are heated so as to be able to generate a thermionic beam when an electric current is applied thereto. Is controlled to release. The back electrode 1 suppresses the generation of electron beams from other line cathodes other than the line cathode controlled to emit the electron beam for a certain period of time, and pushes the generated electron beam forward only. Works. The back electrode 1 may be formed by a coating film of a conductive material attached to the inner surface of the rear wall of the glass bulb. Instead of the back electrode 1 and the linear cathode 2, a planar electron beam emitting cathode may be used.

The vertical focusing electrode 3 is a conductive plate 11 having a horizontally long slit 10 opposed to each of the linear cathodes 2a to 2yo.
Remove through 10 and focus vertically. An electron beam for one horizontal line (360 picture elements) is simultaneously extracted. In the figure, only one of the horizontal sections is shown. The slits 10 may be provided with bars at appropriate intervals in the middle, or may be formed substantially as rows of through holes arranged in small numbers in the horizontal direction (intervals at which they almost touch). May be done. The vertical focusing electrode 3 'is similar.

A plurality of vertical deflection electrodes 4 are horizontally arranged at intermediate positions of the slits 10, each having conductors 13 and 13 ′ provided on the upper and lower surfaces of an insulating substrate 12. Have been. Then, a voltage for vertical deflection is applied between the opposing conductors 13 and 13 ′ to deflect the electron beam in the vertical direction. In this embodiment, a pair of conductors 13 and 13 'deflect the electron beam from one linear cathode 2 to a position corresponding to 16 lines in the vertical direction. The sixteen vertical deflection electrodes 4 constitute fifteen conductor pairs corresponding to the fifteen linear cathodes 2, respectively.
The electron beam is deflected to draw 240 horizontal lines above.

Next, the control electrodes 5 are each formed of a conductive plate 15 having a slit 14 which is long in the vertical direction. A plurality of them are arranged in a horizontal direction at a predetermined interval. 180 in this example
There are provided control electrode conductive plates 15a to 15n (only nine are shown in the figure), and each of the control electrodes 5 takes out an electron beam by dividing the electron beam into two picture elements in the horizontal direction. In addition, the passing amount is controlled in accordance with a video signal for displaying each picture element. Therefore, if 180 conductive plates 15a to 15n for the control electrode 5 are provided, 360 picture elements can be displayed per horizontal line. In order to display an image in color, each picture element is represented by a phosphor of three colors of R, G, and B, and each control electrode 5 has R, G, and B of two picture elements. Each video signal is added sequentially. In addition, 180 sets of video signals for one line (two picture elements per set) are simultaneously applied to each of the 180 conductive plates 15a to 15n for the control electrode 5, and an image for one line is displayed at a time. You.

The horizontal focusing electrode 6 is composed of a conductive plate 17 having a plurality of vertically long (180) slits 16 opposed to the slits 14 of the control electrode 5, and the electrons for each picture element divided in the horizontal direction are provided. The beams are each focused in the horizontal direction to form a thin electron beam.

A plurality of horizontal deflection electrodes 7 are provided at a position on both sides of the slit 16 in a vertical direction.
A six-stage 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.
R, G, and B phosphors are sequentially irradiated to emit light. In this embodiment, the deflection range is the width of two picture elements for each electron beam.

The accelerating electrode 8 is composed of a plurality of conductive plates 19 provided at the same position as the vertical deflection electrode 4 in the horizontal direction.
The electron beam is accelerated to strike the screen 9 with sufficient energy.

The screen 9 has a structure in which a phosphor 20 that emits light when irradiated with an electron beam is applied to the back surface of a glass plate 21 and 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 5, that is, for each electron beam divided in the horizontal direction. Is provided,
It is applied in stripes in the vertical direction. In FIG. 2, broken lines drawn on the screen 9 indicate vertical divisions displayed corresponding to the plurality of line cathodes 2, respectively.
The dashed line indicates the horizontal division displayed corresponding to each of the plurality of control electrodes 5. In one section partitioned by these two, there are two picture elements of R, G, B phosphors 20 in the horizontal direction and 16 lines in the vertical direction, as shown in an enlarged manner in FIG. Has a width of The size of one section is, for example, 1 mm in the horizontal direction and 9 mm in the vertical direction.

It should be noted that, in FIG. 2, the length in the horizontal direction is greatly extended in the vertical direction for easy understanding.

In this example, only one pair of R, G, B phosphors 20 for two picture elements is provided for one control electrode 5, that is, one electron beam. Or three or more picture elements, in which case the control electrode 5
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.

Next, a basic configuration of a drive circuit for displaying a television image on the display element will be described with reference to FIG. First, a driving portion for irradiating the screen 9 with an electron beam to emit a raster will be described.

A circuit for the power supply circuit 22 for applying a predetermined bias voltage (operating voltage) to the electrodes of the display element, the back electrode 1 -V _1, the vertical focusing electrode 3,3 'V ₃ in, V _3' , Horizontal focusing electrode 6
V _6, V ₈ in accelerating electrode 8, the screen 9 applies a DC voltage of V ₉ to.

Next, a composite video signal of a television signal is applied to an input terminal 23, and a vertical synchronizing signal V and a horizontal synchronizing signal H are separated and extracted by a sync separation circuit 24.

The vertical deflection driving circuit 40 includes a vertical deflection counter 25, a memory 27 for storing a vertical deflection signal, and a digital-analog converter 39 (hereinafter referred to as a DA converter). As an input pulse of the vertical deflection drive circuit 40, a vertical synchronization signal V and a horizontal synchronization signal H shown in FIG. 5 are used. The vertical deflection counter 25 (8 bits) is reset by the vertical synchronization signal V and counts the horizontal synchronization signal H.
The vertical deflection counter 25 counts an effective scanning period (a period of 240H in this case) excluding the vertical blanking period in the vertical cycle, and this count output is supplied to the address of the memory 27. The data of the vertical deflection signal (10 bits in this case) corresponding to each address is output from the memory 27, and is converted by the DA converter 39 into the vertical deflection signals of V and V 'shown in FIG. In this circuit, there is a memory address that stores the vertical deflection signal corresponding to each line of 240H, and by storing regular data in the memory every 16H, 16 levels of vertical deflection signal can be obtained. it can.

On the other hand, the line-cathode drive circuit 26 generates a line-cathode drive pulse [A to Y] using the vertical synchronization signal V and the output of the vertical deflection counter 25. FIG. 6A shows the relationship among the vertical synchronizing signal V, the horizontal synchronizing signal H and the lower 5 bits of the vertical deflection counter 25. FIG. 6b shows a method of producing a line cathode drive pulse [I'-Y '] every 16H using these signals. In FIG. 6, LSB indicates the least significant bit, and (LSB + 1) indicates
Means the bit one higher than LSB.

The first line cathode drive pulse [i '] is the vertical synchronizing signal V
And the output (LSB + 4) of the vertical deflection counter 25 and can be created by an RS flip-flop or the like. B ') for vertical deflection counter
It can be obtained by transferring the inverted output of 25 (LSB + 3) as a clock. The driving pulses [a 'to [o]] are inverted to have a low potential only during each pulse period, and are converted to a high potential of about 20 volts during the other periods. Is added to each of the line cathodes 2a to 2y.

Each of the line cathodes 2a to 2yo is heated by applying a current during the high potential of the drive pulse [i to yo] so that electrons can be emitted during the low potential period of the drive pulse [a to yo]. The heating state is maintained. As a result, 15 line cathodes 2a to 2
Electrons are emitted only during the 16H period in which the low-potential drive pulses [A to Y] are applied. During the period in which the high potential is applied, the potential is applied to the linear cathodes 2a to 2y higher than the potential at the position of the linear cathode 2 determined by the bias voltage applied to the back electrode 1 and the vertical focusing electrode 3. Because the higher potential is positive, the line cathode 2
No electrons are emitted from (a) to (2). Thus, in the linear cathode 2, during the effective vertical scanning period, electrons are sequentially emitted from the upper linear cathode 2a toward the lower linear cathode 2yo for 16H periods.

The emitted electrons are pushed forward by the back electrode 1, pass through the opposed slits 10 of the vertical focusing electrode 3, are focused in the vertical direction, and become a plate-like electron beam.

Next, the linear cathode drive pulse (A to Y) and the vertical deflection signal V,
The relationship with V 'will be described with reference to FIG. The vertical deflection signals V and V 'change by 1H during the 16H period of each line cathode pulse [A to Y] and change in 16 steps. 'But both the center voltage is V ₄ and, V is sequentially increased, V' vertical deflection signals V and V, as slide into successively reduced, have been made to vary in opposite directions. These vertical deflection signals V and V 'are applied to the electrodes 13 and 13' of the vertical deflection electrode 4, respectively. As a result, the electron beams generated from the linear cathodes 2a to 2d are deflected in 16 steps in the vertical direction. Then, as described above, on the screen 9, the raster of 16 lines is deflected by one electron beam so as to sequentially draw one line at a time from the top.

As a result, electron beams are emitted for 16 H periods in order from the upper one of the fifteen linear cathodes 2a to 2yo, and each electron beam is sequentially shifted from top to bottom within 15 vertical sections.
By being deflected line by line, the electron beam is vertically deflected one line at a time on the screen 9 from the first line at the upper end to the 240th line at the lower end.
A raster of the line is drawn.

The electron beam vertically deflected in this manner is divided into 180 sections in the horizontal direction by the control electrode 5 and the horizontal focusing electrode 6 and extracted. FIG. 2 shows one of the sections. The passing amount of this electron beam is controlled by the control electrode 5 for each section, and the electron beam is focused in the horizontal direction by the horizontal focusing electrode 6 to form one thin electron beam.
R, G, and B phosphors 20 corresponding to two picture elements on the screen 9 are horizontally deflected by a horizontal deflecting means in six stages.
Are sequentially irradiated. FIG. 3 shows vertical and horizontal divisions. Each phosphor corresponding to 15a~15n the two pixels worth R of the control electrode 5, G, B to become for convenience of explanation, the one picture element R _1, G _1, B ₁ and the other R _2, G ₂ and B ₂ .

Next, the horizontal deflection driving circuit 41 includes a horizontal deflection counter (11 bits) and a memory storing a horizontal deflection signal.
29 and a DA converter 38. The input pulse of the horizontal deflection driving circuit 41 is synchronized with the vertical synchronizing signal V and the horizontal synchronizing signal H as shown in FIG.
A pulse 5H with a double repetition frequency is used.

The horizontal deflection counter 28 is reset by the vertical synchronizing signal V and counts the horizontal 6 times pulse 6H. This horizontal deflection counter 28 is 6 times during 1H and 240H during 1V.
× 6 / H = 1440 times, and this count output is stored in memory 2
Supplied to 9 addresses. The horizontal deflection signal data (8 bits in this case) corresponding to the address is output from the memory 29, and is converted by the DA converter 38 into a horizontal deflection signal such as h, h 'shown in FIG. . In this circuit, there is a memory address for storing a horizontal deflection signal corresponding to each of 6 × 240 lines, and by storing six regular data in the memory for each line, 6
A horizontal deflection signal of a step wave can be obtained.

The horizontal deflection signal is 'a, both of central voltage is V _7, h is sequentially decreased, h' a pair of horizontal deflection signals h and h that varies six stages as shown in Fig. 4 sequentially increases Change in the opposite direction to each other. These horizontal deflection signals h and h 'are applied to the electrodes 18 and 18' of the horizontal deflection electrode 7, respectively. As a result, each electron beam divided in the horizontal direction is applied to the R, G, B, R, G, B of the screen 9 during each horizontal period.
The phosphors (R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , B ₂ ) are horizontally deflected so that the phosphors are sequentially irradiated with H / 6 at a time. Thus, in the raster of each line, the electron beam is R
_The phosphors 20 of ₁ , G ₁ , B ₁ , R ₂ , G ₂ , and B ₂ are sequentially irradiated.

Therefore, the electron beam is applied to each horizontal section of each line by R ₁ , G ₁ ,
By modulating the _{B 1, R 2, G 2} , B 2 of the video signal,
A color television image can be displayed on the screen 9.

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

First, the composite video signal applied to the television signal input terminal 23 is applied to a color demodulation circuit 30, where the RY and BY color difference signals are demodulated and the GY color difference signals are matrix-combined. Then, they are combined with the luminance signal Y, and each of the R, G, B primary color signals (hereinafter referred to as R, G, B video signals)
Is output. These R, G, and B video signals are applied to 180 sets of sample and hold circuit sets 31a to 31n. Each sample-and-hold circuits sets 31a~31n each for R _1, for G _1, for B _1, R ₂
Use, for G _2, has six sample and hold circuits for B _2. These sample hold outputs are applied to holding memory sets 32a to 32n, respectively.

On the other hand, the reference clock oscillator 33 is constituted by a PLL (phase-locked loop) circuit or the like, in this embodiment generates six times the reference clock 6 _SC twice the reference clock 2 _SC of the color subcarrier _SC. The reference clock is controlled so as to always have a fixed phase with respect to the horizontal synchronization signal H. The reference clock 2 _SC is applied to the deflection pulse generation circuit 42, and the signals 6H and H /
Pulses of the signal switching pulses r ₁ , g ₁ , b ₁ , r ₂ , g ₂ , b ₂ are obtained for every six. On the other hand, the reference clock 6 _SC is applied to the sampling pulse generation circuit 34, where the shift register
The horizontal cycle (63.5
μsec) during the effective horizontal scanning period (about 50 μsec)
1080 sampling pulses B _{a1 to} B _n2 are sequentially generated,
Thereafter, one transfer pulse t is generated. The sampling pulses R _{a1 to} B _n2 correspond to the respective picture elements when one line of an image to be displayed is divided into picture elements in the horizontal direction 360, and the positions thereof are always constant with respect to the horizontal synchronization signal H. Is controlled so that

The 1080 sampling pulses R _a1 .about.B _n2 respectively
Six are added to each of the 180 sample-and-hold circuit sets 31a to 31n, whereby each of the sample-and-hold circuit sets 31a to 3n is added.
1n is 2 when each line is divided into 180
Each video signal of picture elements R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , B ₂ is individually sampled and held. The sampled and held 180 sets of R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , and B ₂ video signals are simultaneously transmitted to the 180 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. This retained R ₁ , G ₁ , B ₁ , R ₂ ,
The signals of G ₂ and B ₂ are applied to the switching circuits 35a to 35n. Each switching circuit 35a~35n has _{R 1, G 1, B 1} , R
₂ , G ₂ , and B ₂ , and a tri-state or analog gate having a common output terminal for sequentially switching and outputting them.

The output of the switching circuit 35a~35n is added to 180 pairs of pulse-width modulation (PWM) circuit 37A～37n, wherein, R _1, G ₁ sampled and _{held, B 1, R 2, G} 2, B 2 The reference pulse signal is pulse-width modulated according to the magnitude of the video signal and output. It is desirable that repeated period of the reference pulse signal is intended the signal switching pulses r ₁ of, g _1, b _1, r _2, g _2, b sufficiently smaller than the _second pulse width, for example, 1: 10 1:10
About 0 is used.

The outputs of the pulse width modulation circuits 37a to 37n are used as control signals for modulating the electron beam by the control electrodes 5 of the display element.
Each of the 180 conductive plates 15a to 15n is individually added.
Switching pulse r ₁ each switching circuit 35a~35n is applied from the switching pulse generation circuit _{36, g 1, b 1,} r 2,
Switching control is performed simultaneously by g ₂ and b ₂ . The switching pulse generation circuit 36 is controlled by the signal switching pulses r ₁ , g ₁ , b ₁ , r ₂ , g ₂ , b ₂ from the deflection pulse generation circuit 42 described above, and divides each horizontal period into six. by H / 6 switches the switching circuit _{35a~35n, R 1, G 1,} B 1, R 2, G 2, and sequentially outputs the time division of each video signal of B _2, the pulse width modulation circuit 37a~37n The switching signals r ₁ , g ₁ , b ₁ , r ₂ , g ₂ , b ₂ are generated so as to be supplied.

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
The horizontal switching of the switching of the irradiation of the phosphors of G ₂ and B ₂ is controlled synchronously so that the timing and the order completely coincide with each other. This makes the electron beam
When it is irradiated in R ₁ fluorescent body irradiation amount of the electron beam is controlled by the R ₁ video signals is controlled similarly for _{G 1, B 1, R 2} , G 2, B 2, each picture Raw R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , B
₂ results in the emission of the phosphor is controlled respectively by the _{R 1, G 1, B 1} , R 2, video signals of G _2, B ₂ of the picture element, in accordance with the video signal of each picture element is input Light emission is displayed. This control is performed simultaneously for 180 sets (one picture element each) of one line to display an image of 360 picture elements for one line, and further for the 240 minute line, it is sequentially performed from the upper line to the screen 9. Will be displayed on the screen.

The above operations are repeated for each field of the input television signal, and as a result, a television image of a moving image is displayed on the screen 9 in the same manner as a normal television receiver.

However, in the above configuration, the focusing electrodes 3, 3 'used by applying a DC voltage, the deflecting electrodes 4, 7 applying a control signal, and the beam flow control electrode 5 are composed of an image display element. In order to prevent the control signal from being transmitted to the focusing electrodes 3 and 3 'via the capacitors, the output impedance of the DC voltage application circuit is reduced, and the focusing electrodes are always connected to the DC voltage. I needed to be. However, this method has a problem that the power of the DC voltage application circuit increases.

The present invention has been made in view of the above circumstances, and has as its object to provide an image display device having a DC voltage application circuit with low power consumption.

Means for Solving the Problems To solve the above problems, the image display device of the present invention has a configuration in which a resistor is inserted between a focusing electrode and a DC voltage application circuit, and a capacitor is connected between the focusing electrode and ground. It was made.

According to the present invention, the control signal of the deflection electrode and the beam flow control electrode, which is capacitively coupled to the focusing electrode, propagates to the focusing electrode via the capacitor by the above-described configuration. It can be divided and reduced by the ratio of the capacitance value between the focusing electrode and the capacitance value of the capacitor connected between the focusing electrode and the ground, and the image quality is deteriorated by supplying the potential of the focusing electrode from the DC voltage application circuit via the resistor. Therefore, the power consumption of the DC voltage application circuit can be reduced.

Embodiment Hereinafter, an image display device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1a shows an equivalent circuit of a focusing electrode and a beam flow control electrode of an image display device according to an embodiment of the present invention, and respective drive circuits. FIG. 2B shows waveforms at the beam flow control electrode and the focusing electrode.

In FIG. 1, reference numeral 61 denotes a beam flow control electrode driving circuit;
Is a connection terminal of the beam flow control electrode, 63 is a capacitor equivalently representing the capacitance between the beam flow control electrode and the focusing electrode, 64 is a connection terminal of the focusing electrode, and 65 is a terminal for increasing the output impedance of the DC voltage application circuit 67. A resistor 66 is provided between the ground and the ground to reduce the amplitude of the signal appearing at the connection terminal 64 by dividing the beam flow control signal 68 propagating through the capacitor 63 by the capacitance ratio of the capacitor 63 and 67 is a resistor. DC voltage application circuit equivalently shown, 68 is a signal applied to connection terminal 62, 69 is a signal appearing at connection terminal 64, 70 is a signal
It shows 69 pedestal levels.

Regarding the image display configured as above, the first
The operation will be described with reference to the drawings.

A control signal 68 is applied from the drive circuit 61 to the connection terminal 62 of the beam flow control electrode. This signal passes through the capacitor 63 and appears at the connection terminal 64. The amplitude of this signal is
The signal is divided by the capacitance ratio of the capacitors 63 and 66 to become a signal 69.
By making the capacity of the capacitor 66 sufficiently larger than that of the capacitor 63, the amplitude of the signal 69 can be reduced so as not to affect the focus of the electron beam. The pedestal level 70 of the signal 69 is given by the DC voltage application circuit 67 and the resistor 65, and the current flowing out of the DC voltage application circuit 67 can be reduced.

As described above, according to the present embodiment, by inserting a resistor between the focusing electrode and the DC voltage applying circuit and connecting a capacitor between the focusing electrode and the ground, the DC voltage applying circuit can be performed without deteriorating the image quality. Power consumption can be reduced.

Effects of the Invention As described above, according to the present invention, a resistor is inserted between the focusing electrode and the DC voltage application circuit, and a capacitor is connected between the focusing electrode and the ground, without deteriorating the image quality. In addition, the power of the DC voltage application circuit can be reduced.

[Brief description of the drawings]

FIG. 1 is an equivalent circuit diagram and a waveform diagram of a beam flow control electrode and a focusing electrode of an image display device according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of an image display element used in a conventional image display device. FIG. 3 is an enlarged front view of the image display device,
FIG. 4 is a block diagram showing a basic configuration of a driving circuit of the image display device, FIG. 5 is a waveform diagram for explaining an operation of a vertical deflection driving, and FIG. 6 is a waveform for explaining an operation of a linear cathode driving circuit. FIG. 7 is a waveform diagram of each drive signal, and FIG. 8 is a waveform diagram for explaining the operation of the horizontal deflection drive circuit. 2,2a ~ 2b ... wire cathode, 3,3 ', 6 ... focusing electrode, 4 ...
Vertical deflection electrode, 5: Beam flow control electrode, 7: Horizontal deflection electrode, 9: Screen, 20: Phosphor, 65: Resistance, 66: Capacitor.

Claims (1)

(57) [Claims] 1. A screen coated with a phosphor which emits light when irradiated with an electron beam, and a line cathode for generating an electron beam for each of vertical divisions of the screen on the screen divided into a plurality of sections. Separation means for separating the electron beam generated by the linear cathode in each horizontal section divided in the horizontal direction and irradiating the screen with the electron beam, and separating the electron beam in the vertical and horizontal directions until the electron beam reaches the screen. A deflection electrode that deflects in a plurality of stages in the direction, and a beam flow control that controls the amount of each pixel on the screen of the screen by controlling the amount of irradiation of the screen with the electron beam separated for each horizontal section. Electrodes, a focusing electrode for controlling the emission size of the electron beam on the phosphor surface by the electron beam, a back electrode for controlling the amount of electron beam from the linear cathode, and the focusing electrode. And a circuit for applying a voltage, a resistor provided between the DC voltage applying circuit and the focusing electrode, an image display device provided with a capacitor between the focusing electrode and the ground.