KR950003137B1 - Amplifier and display device - Google Patents

Abstract

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Description

Amplifier and display device using same

1 is a circuit diagram showing a first embodiment of the present invention.

2 is a specific circuit diagram of the current amplifier circuit shown in FIG.

3 is a system diagram of a high precision display device according to a second embodiment of the present invention.

4 is a block diagram of the video amplifier 300 (300 ', 300 ") shown in FIG.

5 is a specific circuit diagram of the video amplifier 300 shown in FIG.

6 is a system diagram of a high precision display device according to a third embodiment of the present invention.

7 is a cross-sectional view of the device of the integrated circuitized current mirror circuit 1001 (or current mirror circuit A ₁ in FIG. ₅ ) shown in FIG.

8 is a waveform diagram of an output color signal.

9 is a diagram showing another example of the circuit configuration of the preamplifier 24A and the gain adjusting circuit 24B of the preamplifier 24A.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amplifier and a display device using the same, and is particularly suitable for an amplifier having a high cutoff frequency (that is, capable of processing a wideband signal) and having a high amplification factor and a high precision display device using the same.

It is very difficult to obtain an amplifier with a high cutoff frequency and a high output. Considering the integrated circuit (IC) amplifier, the high cutoff frequency means that the F _T (product of the gain bandwidth) of each transistor constituting the amplifier is high, and this does not reduce the size of each transistor formed in the semiconductor substrate. You must. Naturally, since the minute device has a low withstand voltage, even if the IC operating power supply voltage (Vcc) is high, a large output cannot be obtained like a power amplifier.

On the contrary, in order to obtain a high output, the size of each transistor must be increased. In this case, the parasitic capacitance of each transistor is increased, and the frequency characteristics deteriorate.

In this way, increasing the cutoff frequency of the amplifier and improving the amplification rate were originally limited to each other and to match the characteristics of both.

The inventors have recognized that in the development of high precision display devices, a very large amplifier with an operating frequency band of 200 MHz and an output dynamic range of, for example, 0V to 200V is required. In the prior art, for the reasons mentioned above, it was not possible to obtain an IC miniaturized amplifier that is wideband and generates high power.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an amplifier having a high cutoff frequency and a high amplification factor and a high precision display device using the same.

Representative outline for achieving the object of the present invention described above is briefly described as follows.

The amplifier of the present invention includes a voltage-to-current converting means for obtaining an output current corresponding to an input voltage signal, a current amplifying means for amplifying the output current of the voltage-current converting means, and converting the output current of the current amplifying means to a voltage. And current-voltage converting means.

The current amplification means is made into a semiconductor integrated circuit using a miniaturization process technology, so that the frequency characteristics are very good, and the power supply voltage V _CC1 is about 5V.

In order to carry out a large current amplification despite this low power supply voltage, the following studies have been made on the current amplification means.

That is, a plurality of current amplifiers for multiplying the current I _IN transmitted from the above-described voltage-current conversion means by n times (n≥1, n is an integer) are provided, and the output currents of these current amplifiers are synthesized as a result. To get the current.

More specifically, one current amplifier comprises a current mirror circuit having a ratio of current mirrors (i.e., a current I _IN flowing from a reference transistor to an output current) of 1: n, and the current mirror circuits are arranged in parallel m circuits. By connecting, the output current with large m * n * _IIN is obtained as a result from the commonly connected output terminal.

The ratio n of the current mirror of the current mirror circuit is set to an appropriate value such as n = 32 which sufficiently secures the accuracy of pairing of the current mirror and does not deteriorate the high frequency characteristics of the current mirror.

Next, the output current obtained from the current amplifying means is converted into voltage using current-voltage converting means (impedance means). This current-voltage converting means is provided separately from the above-described IC-amplified current amplifying means, and its power supply voltage V _CC2 is set to be large, for example, 200V.

The following effects are acquired by the above structure.

(1) Substantially the part that amplifies the input signal is ICized using a miniaturization process technology, so that the size of the elements constituting the amplification circuit is very small, and the parasitic capacitance of each element can be minimized. High speed operation is possible and high frequency characteristics are good.

(2) The current amplifying means does not directly amplify a small amplitude input signal to a large voltage, but first (i) converts the input signal (voltage) into a current and obtains a current I _IN corresponding to the input signal. To (ii) n times the current I _IN to obtain nI _IN current, and (iii) several (m) nI _IN currents are current synthesized to finally obtain an output current of m · n · I _IN .

Even if the amplification rate of a small transistor is small, it is possible to prepare several transistors and combine the respective output currents to obtain an appropriate current, and to add the currents together to obtain a large current, so that a very large output current can be obtained without using any high breakdown voltage device. You can get The above-described configuration can be easily achieved by providing a wide aluminum wiring which allows a large current to be finally obtained in the IC.

(3) The IC-amplified current amplifying means converts the above-described output current into a voltage by using a separately provided current-voltage converting means, and as a result, large voltage amplification can be achieved.

In addition, when a wide display and high output amplifier is used as a color signal amplifier, a color display device is constructed, the electron beam can be scanned at a very high speed due to its good frequency characteristics, so that a very fine image can be reproduced and a large output dynamic range can be obtained. This allows the electron beam output of each color signal (R, G, B) to be adjusted over a very wide range, so that subtle color differences and subtle luminance differences can be reproduced in the receiving tube, providing a very high-precision display device. have.

The above and other objects and novel features of the present invention will become apparent from the description and the accompanying drawings.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated with an Example.

In addition, in all the drawings for demonstrating an Example, the thing with the same function attaches | subjects the same code | symbol, and the repeated description is abbreviate | omitted.

Example 1

A first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

(a) Overall composition

As shown in FIG. 1, the amplifier of this embodiment has a current amplifier 1 of a voltage-to-current conversion method and an impedance element R ₂₀₀ for converting the output current of the current amplifier into a voltage to obtain a voltage output V _OUT . . In addition, in order to maintain the DC voltage level (bias) of the output terminal B at a predetermined potential V _ref , a negative feedback circuit using the operation amplifier 2 is provided.

Since resistor R ₂₁₀ in FIG. 1 has a large resistance value (for example, 20 kΩ), at point B, the present impedance is large and the potential at point B is approximately equal to the potential at line 13 (ie, V _ref ).

This negative feedback loop is configured when the switch S _W controlled by the clock ψ is closed, _{and the} DC bias is held by the holding capacitor C ₂ when the switch S _W is open. The resistance (R ₂₃₀₎ has its resistance value is set larger as 20kΩ.

The current amplifier 1 is integrated circuit, the power supply voltage V _CC1 is set to 5V, for example, as shown in FIG. 1, and the power supply voltage V _CC2 connected to the resistor R ₂₀₀ for voltage-current conversion. Is set to 200V, for example.

(b) feature points

As described below, the current amplifier 1 is integrated circuit using an ultra miniaturization process technique and does not use any one of the PNP transistors having poor frequency characteristics, and only the NPN transistors are used as active elements.

Therefore, the current amplifier 1 can operate at high speed, has good frequency characteristics, and has a band of 200 MHz or more.

On the other hand, in spite of the low supply voltage V _CC1, and to obtain a large output, first converting the input signal into a current I _IN and to the basis of the current I _IN provided a n a doubling current nI _IN and also of the nI _IN A method of synthesizing m currents and consequently obtaining a large current of n · m · I _IN is adopted. In other words, by gradually amplifying the current and summing the amplified currents, a high output current can be obtained without using any high withstand voltage element (large size element, etc.).

In this embodiment, n = 32 and m = 8 are set, and as a result, an output current of 256 times larger than I _In can be obtained. In addition, as will be described later, this output current is obtained in correspondence with the input signal V _IN . Finally, voltage conversion of this large output current using a resistor R ₂₀₀ results in a high amplified output voltage. The amplifier has a very high voltage amplification factor and a wide output dynamic range.

As apparent from FIG. 1, the power supply voltage V _CC1 of the current amplifier (current amplifier) 1 is set to 5V, and the current-voltage converter (current-voltage converter) 400 shown in FIG. The power supply voltage V _CC2 of is set to 200V. That is, the relationship between the power supply voltage V _CC1 of the current amplifier 1 and the power supply voltage V _CC2 of the current-voltage converting means 400 becomes V _CC1 < V _CC2 .

The reason why the power supply voltage V _CC1 of the current amplifier 1 is set to 5 V is that in the current amplifier 1 operating at 200 MHz, the element size of the circuit elements constituting the current amplifier 1 is made very small and each circuit element This is to minimize the parasitic capacity parasitic. That is, the current amplifier 1 is formed by using a low breakdown voltage element having a small element size without using a high breakdown voltage element having a large element size.

As a result, the circuit elements constituting the current amplifier 1 can operate at high speed and have good high frequency characteristics. As a result, as described later, the current amplifier 1 has a configuration suitable for forming an integrated circuit (IC).

On the other hand, the reason why the current-voltage conversion means 400 is set to 200V the power supply voltage V _CC2 is as follows.

The current-voltage converting means 400 has a function of converting a large current output from the current amplifier 1 into a voltage and outputting it. The output voltage output from the current-voltage converting means 400 is the cathodes K ₁ , K ₂ , of the cathode tube (cathode ray tube: CRT) 500 in the color display apparatus as shown in FIG. It is used as an applied voltage to K ₃ . The voltages applied to the cathodes K ₁ , K ₂ , and K ₃ become the control voltages of the respective electron guns of red, green, and blue, which are three primary colors. Therefore, the larger the change range of the applied voltage to the cathodes K ₁ , K ₂ , K ₃ , that is, the larger the dynamic range of the applied voltage, the more the range of the electron beam output from the corresponding electron gun can be adjusted. This means that the cathode tube 500 can reproduce subtle color differences and subtle luminance differences.

For the above reasons, the power supply voltage V _CC2 of the current-voltage converting means 400 is higher than the power supply voltage V _CC1 (5V) of the current amplifier 1, for example, a high voltage such as 200V.

(c) specific configuration of the current amplifier;

2 shows a specific circuit configuration of the current amplifier 1.

In FIG. 2, the portion 1000 surrounded by the dotted line is a voltage-to-current conversion circuit for obtaining the current I _IN corresponding to the input signal V _IN . Likewise, the lines 1001 to 100m enclosed by the dotted line represent the current I _IN . The multiplication is a current mirror circuit as a current amplifier.

The large output current I _OUT (I _OUT = m) at the output line l ₂ by wire-connecting the output terminals of these m current mirror circuits at the point C, for example, and performing current synthesis here. N · I _IN ) is obtained.

The circuit operation will be described in more detail as follows.

That is, the input signal V _IN is input to the base of the transistor Q ₂₀₀ along the coupling capacitor C ₁ along the line l ₁ , and obtains a current I _S corresponding to the input voltage at the emitter. Referenced to the current I _S, using a current mirror providing a multiple of the current I _X and the current changing in response to the input signal V _IN by subtracting the current I _S from the current I _X I _N (I _N = I _X -I _S ) is obtained and input into each of the current mirror circuits.

By again using a current mirror circuit (1001) ~ (100m) of the current I _IN n times (32 times), and also by combining the outputs of each of the current mirror circuit (1001) ~ (100m), as a result I _OUT ( I _OUT = m · n · I _IN ).

In order to obtain an output corresponding to the input V _IN accurately and to improve frequency characteristics, the following studies have been made.

That is, as shown in FIG. 2, a plurality of current mirror circuits 1001 to 110m are provided, and each of the current mirror circuits includes a plurality of output transistors (three in this example) for one reference transistor. have.

For the purpose of obtaining only a large current, one current mirror circuit may be prepared, and in the current mirror circuit, multiple output transistors may be provided for one reference transistor to synthesize the outputs of the respective output transistors.

However, in this configuration, the parasitic capacitance between the base and the collector in the output transistor of the current mirror circuit increases, and the high frequency characteristic is significantly deteriorated.

This is evident in light of the IC device structure.

FIG. 7 is a cross-sectional view of the IC device of the current mirror circuit 100 (also (1002) to (100m) is the same) shown in FIG. First, the structure of the current mirror circuit 1001 will be briefly described.

An N-type epitaxial layer 5 is provided on the P ⁻ type substrate 3, and an N ⁺ type buried layer 4 is partially formed between the substrate 3 and the epitaxial layer 5.

N ^- type epitaxial layer has in part a groove 17 is formed and, a bottom portion of the groove and the P ^- by the P ⁺ secretion layer 6 which connects the shaped substrate (3) N ^- type epitaxial layer has several It is divided into island regions of. In this island region, NPN transistors Q ₂₆₀ and Q ₂₇₀ are formed using photolithography techniques, respectively. The thickness of the N ⁻ type epitaxial layer is, for example, 1.7 μm, the depth of the bases 7, 8 of the transistor is 0.7 μm, for example, the depth of the emitters 9, 10 is 0.4, for example. It is micrometer and is very fine IC. Further, the groove 17 partially provided in the epitaxial layer 5 can minimize the diffusion of the separation layer 6 in the lateral direction, and can make the collector series resistance of the transistor very small. As can be clearly seen from the above description, the current amplifier is formed by using an ultra-fine process technology to enable high-speed operation and very high frequency characteristics.

Here, the parasitic stray capacitance C _f between the base and the collector of the output transistor of the current mirror circuit described above is considered. As can be seen in FIG. 7, as the number of output transistors of the current mirror circuit increases, the stray capacitance C _f between the base and the collector and the parasitic capacitance C _p between the collector and the substrate increase. Therefore, in the present invention, the number of output transistors in each of the current mirror circuits is suppressed to a certain value or less to prevent an increase in parasitic capacitance.

Moreover, when there are many output transistors with respect to one reference transistor in a current mirror circuit, the precision of the ratio of the current mirror resulting from the base current of each transistor will arise. In order to prevent this and to obtain an accurate output current corresponding to the input signal V _IN , it is effective to keep the number of output transistors below a certain value.

(d) Study for reducing temperature dependence of bias current in current mirror circuit

In the current mirror circuit shown in FIG. 2, important studies have been made to reduce the temperature dependency of the input current I _IN . That is, the input I _IN of the current mirror circuit represents I _IN = I _X -I _S , and is obtained as a difference between two currents I _X and I _S. In practice, this current I _X and current I _S are supposed to change equally when the ambient temperature of the IC changes (i.e. the temperature characteristics are consistent), and as a result, the input I _IN (I _X -I _S ) is approximately constant.

This can be understood by the following equation. In other words,

The following equations are obtained from equations (1) and (2).

If R ₆₁ = R ₆₀ + R ₁₁₀ is selected in the third and fourth terms of equation (3), the term containing V _BE disappears and the temperature dependence of the current I _IN is completely raised. That is, the voltage V _BE between the base and the emitter of the transistor has a temperature characteristic of about -2 mV / ° C., but this temperature characteristic is completely canceled out so that the input current I _IN of the current mirror circuit is safe regardless of the ambient temperature.

Example 2

3 shows the configuration of a high precision display device as a second embodiment of the present invention. The video amplifiers 300, 300 ', and 300 "correspond to the current amplifiers of the voltage-current conversion method shown in FIG. 1, and the I / V (current-voltage) converting means 400, 400' , 400 " corresponds to R ₂₀₀ in FIG. Specific configurations of the video amplifiers 300, 300 ', 300 ", I / V converting means 400, 400', 400 " will be described in detail with reference to FIGS. Explain.

(a) Overall composition

As shown in FIG. 3, the high-precision display device displays digital color signals of red (R), green (G), and blue (B) transmitted from the CPU 100 and the CPU 100. As shown in FIG. D / A converter 200, 200 ', 200 ", I / V converting means 400, 400', 400 " and CRT 500 for converting an analog signal.

The luminance of the image displayed on the CRT is controlled by the applied voltages of the cathodes K ₁ , K ₂ , K ₃ , and the color is determined by the mixing ratio of R, G, and B.

The output lines l ₃ , l ₄ , l ₅ of the D / A converter obtain a high frequency signal of, for example, a band of 200 MHz and are input to the video amplifiers 300, 300 ′, and 300 ″. ), (300 '), (300 ") are each individually integrated circuit into a voltage-current type current amplifier using ultra-fine process technology. The output voltage is obtained by converting the output currents obtained by these video amplifiers into I / V, and these output voltages are applied to the cathodes K ₁ , K ₂ , and K ₃ .

As a result, electrons are emitted from the cathode to emit light of fluorescent elements (not shown) of each color to obtain a desired color image.

Since the scanning line (raster) in this CRT is 1000 lines or more, a very dense image is obtained.

(b) feature points

i) Since each video amplifier is ICized using an ultra-fine process technology, the high frequency characteristic is good. This makes it possible to scan the electron beam at a very high speed.

ii) A large current output is obtained in the video amplifier, and a large output voltage is obtained by finally converting the voltage so that the output dynamic range is very wide. As a result, it is possible to precisely control the voltage applied to the cathode and to express subtle color differences.

iii) Since each video amplifier is individually ICized, crosstalk between R, G and B signals is completely prevented.

(c) specific overall configuration of video amplifiers and I / V conversion means;

4 is a block diagram of a video amplifier and I / V conversion means. 5 is a circuit diagram showing a more specific circuit configuration.

First, it demonstrates according to FIG. In Fig. 4, the IC is able to obtain a composite video signal by two inputs V _IN1 and V _IN2 having two input terminals (① pin and ② pin). (21A) and (21B) is a buffer circuit which receives a signal V _IN1 and V _IN2 signal of the TTL level. The switches S ₁ and S ₂ are controlled by the control circuits 23a and 23b. The outputs of the buffer circuits 21A and 21B are input to the current amplifier circuit 25 of the voltage-current conversion method through the preamplifier 24 (the gain of the preamplifier is variable by the control signal V _c ). do. The output of the current amplifier circuit 25 is converted into a voltage by the I / V conversion resistor R _L of the I / V conversion means 400 provided outside the IC. Transistors Q ₂₀ and Q ₂₂ are provided to prevent oscillation. In addition, in order to stably set the DC bias of the output line l _OUT , a negative environment path composed of resistors R ₇ and R ₈ , an operational amplifier 27a, a buffer amplifier 27b, and a resistor R _A (R _B ) is provided. have.

The switch S3 finished in the negative environment path is controlled by the control circuit 27c, which is controlled by the pedestal level clamp pulse V _D.

The timing at which this pedestal level clamp pulse is applied will be described with reference to FIG.

8 shows the output color signal V _O represented by the output line l _OTT , where "H" is a horizontal synchronization signal. The above-described pedestal level clamp pulse V _D is applied during the period T in the figure, and the potential of the pedestal level P is fixed to the reference potential V _ref2 by performing negative feedback at this time.

(d) specific circuit arrangement of video amplifiers and I / V conversion means;

FIG. 5 shows a more specific circuit configuration of the IC shown in FIG. In Fig. 5, the same reference numerals are given to the same parts as in Fig. 4.

The buffer circuits 21A and 21B are composed of an NPN transistor Q ₁ (Q ₄₁ ) that receives an input signal and a current mirror circuit. The switch S ₁ (S ₂ ) consists of a diode Q ₄ (Q ₅ ) using a transistor. Relationship of the switch S ₁ and _a control signal V is as follows.

For example, when the control signal V _a is at the "H" level, the constant current I sent from the constant current source I _S9 drives the base of the transistor Q ₃₈ via the diodes Q ₃₅ and Q ₃₇ to turn on the transistor Q ₃₈ . As a result, the collector of this transistor Q ₃₈ becomes approximately ground potential, diode Q ₄ is reverse biased, and signal transmission is prevented.

On the other hand, when the control signal V _a is at the "L" level, the current sent from the constant current source I _S9 is classified in the direction of the input terminal V _a via the diode Q ₃₄ , and the transistor Q ₃₈ is "off". As a result, the anode potential of the diode Q ₄ is biased by the rising order of the diode Q _4, a diode, a signal transmission is performed by the operation as the level shift means.

The preamplifier 24A consists of a constant current source consisting of a base ground transistor Q ₉ , a transistor Q ₈ and a resistor R ₅ and a load resistor R 4. The base potential of the transistor Q ₈ is controlled by the control voltage Vc applied at the seventh pin, and as a result, the bias current is changed, whereby the gain of the preamplifier is precisely controlled.

Further, another circuit configuration of the preamplifier 24A and the circuit 24B for precisely adjusting the gain of the preamplifier 24A is shown in FIG.

By varying the control voltages V _Q and V _R applied to the transistors Q ₅₆ and Q ₅₇ , which form the differential pairs in the gain precision adjustment circuit 24B, as a result, the current I _X and the current in the preamplifier 24A are changed. The amount of synthesized current of I _Y changes. As a result, the voltage drop generated in the resistor R ₅₁ changes so that gain adjustment is performed. The constant currents I _A and I _B differ in their current amounts.

Since the circuit configuration from the emitter follower Q ₁₀ to the ninth pin, which is the output pin of the IC after receiving the output of the preamplifier, is the same as that shown in Fig. 2, the description of the circuit configuration and circuit operation is omitted.

The voltage-current (V / I) converting means 400 is composed of a load resistor R ₂₁ and transistors Q ₂₀ and Q ₂₁ provided for preventing oscillation.

The negative feedback input is applied to the base of Q ₂₃ of transistors Q ₂₂ and Q ₂₃ that are differentially paired at the pin. The switch S ₃ consists of transistors Q ₂₈ and Q ₂₉ . Paddy-level clamp pulse V _D (“H” level) is input, and the current sent from the constant current source I _SS that has flowed in the ⑫ pin direction now drives the base of diode Q ₃₄ and Q ₃₇坼 transistor Q ₃₂ . This is "on". As a result, the base potential is supplied to the transistors Q ₂₈ and Q ₂₉ constituting the switch S ₃ to perform signal transmission.

The negative feedback signal is fed back to the input signal lines l _3a and l _3b via the buffer amplifier 27b and the negative feedback line l ₁₀ .

Example 3

6 shows another embodiment of the present invention. The circuit configuration of this high-precision display device is substantially the same as in the second embodiment, except that the video amplifiers for the color signals of R, G, and B are integrally integrated with the IC, and the I / V conversion means are integrated with the IC. Is that there is.

By integrated IC of each video amplifier, the temperature characteristics of each amplifier (change in amplification rate when the ambient temperature is changed) coincide.

In addition, since the I / V conversion means is also IC, the display device can be configured more compactly.

IC 401 is manufactured using high breakdown voltage device process technology.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

Claims (57)

An amplifier for processing a video signal, comprising: a first power supply voltage formed on a semiconductor substrate and having a first predetermined voltage level to supply an amplified output current according to an input signal corresponding to the video signal; A second power supply voltage provided outside the current amplifying means and the semiconductor substrate to receive the output current and having a second predetermined voltage level greater than the first predetermined voltage level of the first power supply voltage. And current-voltage conversion means for converting the output current into an output voltage, wherein the current amplifying means generates voltage-current conversion means for generating an input current signal according to the input signal in response to the input signal. A plurality of current amplifying circuits and the plurality of currents coupled to the current converting means, each forming a current signal amplified according to the input current signal It synthesizes the respective amplified current signal formed by the width of the circuit forming the output current, the output current, the current-amplifier including a current supplied to the synthesis means for voltage converting means. 2. The apparatus of claim 1, wherein the input signal is input to the current amplifying means via a coupling capacitor, the current amplifying means and the current-voltage converting means are directly connected by a direct current bias method, and the current-voltage converting means. And an auxiliary feedback means is coupled between the output terminal of the current-voltage converting means and the input terminal of the current amplifying means to maintain the bias of the output terminal of the amplifier. The amplifier according to claim 1, wherein the current-voltage converting means includes impedance means for converting the output current generated by the current synthesizing means into the output voltage. 4. The apparatus of claim 3, wherein the current amplifying means further comprises means for forming a plurality of current signals coupled between the voltage-current converting means and the current amplifying circuit to be applied to the current amplifying circuit. Each one of which is applied to each one of the current amplifier circuits. 5. The amplifier of claim 4, wherein each of the current amplifier circuits comprises means for n times the current signal received by the current amplifier circuit, where n is an integer. 6. The amplifier of claim 5 wherein each of the current amplifier circuits comprises a current mirror circuit having a reference transistor and a plurality of output transistors coupled to the reference transistor such that the flow of their current is controlled by the reference transistor. The method of claim 6, wherein generating a current signal (I _X) is the current signal and one contains have the same temperature characteristic of the current signal generation means for generating a current signal (I _X) also in the in the current mirror circuit The current signal (I _IN ) to be applied to the reference transistor is determined by the difference between the generated current signal (I _X ) and the current signal. 8. The amplifier of claim 7, wherein the reference transistor and the output transistor in the current amplifier circuit are bipolar NPN transistors. A current amplifier formed on one semiconductor substrate, comprising: current-voltage conversion means for generating an input current signal corresponding to the input signal in response to an input signal to be supplied from the outside of the semiconductor substrate, and to the voltage-current conversion means. A current mirror circuit having a plurality of output transistors coupled to the reference transistor, each coupled to form a current signal amplified in accordance with the input current signal, such that a flow of the reference transistor and their current is controlled by the reference transistor. And a current synthesizing means for synthesizing each of the amplified current signals formed by the plurality of current amplifier circuits and the plurality of current amplifier circuits to form a synthesized current, and supplying the synthesized current to the outside of the semiconductor substrate. Current amplifier. 10. The apparatus of claim 9, further comprising means for coupling between said voltage-current converting means and said current amplifier circuit to form a plurality of current signals intended to be applied to said current amplifier circuit. A dog amplifier is applied to each one of the current signals. The method of claim 9 wherein generating a current signal (I _X) is the current signal and one contains have the same temperature characteristic of the current signal generation means for generating a current signal (I _X) also in the in the current mirror circuit The current amplifier (I _IN ) to be applied to the reference transistor is determined by the difference between the generated current signal (I _X ) and the current signal. 10. The current amplifier of claim 9, wherein the reference transistor and the output transistor of the current amplifier circuit are bipolar NPN transistors. A current amplifier formed on one semiconductor substrate and processing an image signal, the current amplifier generating an input current signal according to the input signal in response to an input signal corresponding to the image signal supplied from the outside of the semiconductor substrate. Coupled to a voltage converting means, said voltage-current converting means, each forming an amplified current signal in accordance with said input current signal, and coupled to said reference transistor such that the flow of a reference transistor and their current is controlled by said reference transistor. A plurality of current amplifier circuits including a current mirror circuit having a plurality of output transistors, and amplified current signals formed by the plurality of current amplifier circuits to form a synthesized current, and the synthesized current is converted into the semiconductor. Current synthesizing means for outputting to the outside of the substrate and phase with the voltage-current conversion means Means for forming a plurality of current signals coupled between the current amplifier circuits to be applied to the current amplifier circuits, wherein each one of the current signals is applied to each one of the current amplifier circuits. . 13. The method of claim 12, generating a current signal (I _X) is the current signal and one contains have the same temperature characteristic of the current signal generation means for generating a current signal (I _X) also in the in the current mirror circuit And a current signal (I _IN ) to be applied to a reference transistor is determined by the difference between the generated current signal (I _X ) and the current signal. 13. The current amplifier of claim 12, wherein the reference transistor and the output transistor in the current amplifier circuit are bipolar NPN transistors. A system comprising a CRT for displaying an image and a driving circuit coupled to the CRT and used for displaying the image on the CRT, wherein the driving circuit is an input signal corresponding to the image to be displayed on the CRT. A first power supply voltage having an input signal supply means for supplying a first supply voltage and a first power supply voltage having a predetermined voltage level and supplying an output current amplified according to one of the input signals and the predetermined power supply voltage; And a current supply voltage converting means for supplying a second power supply voltage having a predetermined voltage level that is greater than a voltage level of and converting the amplified output current into an output voltage to be applied to the CRT. A plurality of amplifiers coupled to receive and amplifying the input signal, the current amplifying means being configured to respond to the input signal. A voltage-current conversion means for generating an input current signal according to a call, a plurality of current amplification circuits coupled to the voltage-current conversion means, each of which forms an amplified current signal according to the input current signal, and the plurality of current amplifications And current synthesizing means for synthesizing each amplified current signal formed by the circuit to form a synthesized current, and supplying the synthesized current to the current-voltage converting means. 17. The system according to claim 16, wherein said input signal supply means comprises a central processing unit for supplying a signal which is the basis of said input signal. 17. The apparatus of claim 16, wherein the input signal supply means is coupled between the central processing unit and the amplifier for supplying a digital signal corresponding to the image to be displayed on the CRT and inputting the digital signal to the input. A system comprising a D / A converter to convert the signal. 17. The system of claim 16, wherein the current amplifying means is formed on an IC, and the current-voltage converting means is provided separately from the outside of the IC. 17. The apparatus of claim 16, wherein the input signal is input to the current amplifying means through a coupling capacitor, the current amplifying means and the current-voltage converting means are directly connected by a direct current bias method, and the current-voltage converting means. And an auxiliary feedback means is coupled between the output terminal of the current-voltage converting means and the input terminal of the current amplifying means to maintain the bias of the output terminal of the amplifier. 20. The system of claim 19, wherein the negative feedback means is controlled by a pedestal level clamp pulse of the input signal. 17. The system of claim 16, wherein the plurality of amplifiers are formed on an IC independently of each other. 17. The system of claim 16, wherein the plurality of amplifiers are formed on one semiconductor substrate. 17. The system of claim 16, wherein each current-voltage converting means of the amplifier is formed on one semiconductor substrate. 17. The apparatus of claim 16, further comprising an analog switch circuit for selectively transferring a predetermined one of the plurality of input signals, wherein the analog switch circuit controls its signal transfer by controlling its anode potential by a control transistor. A system comprising a diode consisting of a controlling transistor. 25. The electronic device of claim 24, wherein the current-voltage converting means includes impedance means for converting the synthesized current generated by the current synthesizing means into the output voltage signal, and the CRT emits electrons having energy from the cathode. And a fluorescent member for emitting light corresponding to the energy of the emitted electrons, wherein the energy of the electrons is controlled by an output voltage signal generated by the impedance means. 17. The apparatus according to claim 16, wherein said amplifying means further comprises means for forming a plurality of current signals to which said voltage-to-current converting means are coupled between said current amplifier circuits and to be applied to said current amplifier circuits, each of said current signals. One of which is applied to each one of said current amplifier circuits. 27. The system of claim 26, wherein the current amplifying means is formed on an IC, and the current-voltage converting means is provided outside the IC. 25. The system of claim 24, wherein each of the current amplifier circuits comprises means for n times the current signal received by the current amplifier circuit, where n is an integer. 29. The system of claim 28, wherein each of the current amplifier circuits comprises a current mirror circuit having a reference transistor and a plurality of output transistors coupled to the reference transistor such that the flow of their current is controlled by the reference transistor. 30. The method of claim 29, generating a current signal (I _X) is the current signal and one contains have the same temperature characteristic of the current signal generation means for generating a current signal (I _X) also in the in the current mirror circuit The current signal (I _IN ) to be applied to the reference transistor is determined by the difference between the generated current signal (I _X ) and the current signal. 30. The system of claim 29, wherein the reference transistor and the output transistor in the current amplifier circuit are bipolar NPN transistors. A system for outputting an output voltage signal intended to be coupled to a CRT displaying an image, the system comprising: an input signal supply means for supplying an input signal corresponding to the image to be displayed on the CRT; A current supply means for supplying an output current amplified in accordance with one of the input signals, coupled to a first line to which a first power supply voltage having a predetermined voltage level is to be supplied, and the predetermined power supply voltage; A current coupled to a second line to be supplied with a second power supply voltage having a predetermined voltage level greater than a voltage level of to convert the amplified output current into one of the output voltage signals to be applied to the CRT- And a plurality of amplifiers each having a voltage converting means and coupled to receive the input signal and amplifying the input signal. Is coupled to the voltage-current conversion means for generating an input current signal according to the input signal and the voltage-current conversion means in response to the input signal to form a plurality of current signals each amplified according to the input current signal. And a current synthesizing means for synthesizing each of the amplified current signals formed by the current amplifier circuit and the plurality of current amplifier circuits to form a synthesized current, and outputting the synthesized current to the current-voltage converting means. 34. The system according to claim 33, wherein said input signal supply means comprises a central processing unit for supplying a signal which is the basis of said input signal. 34. The apparatus of claim 33, wherein the input signal supply means is coupled between a central processing unit for supplying a digital signal corresponding to the image to be displayed on the CRT and between the central processing unit and the amplifier to input the digital signal. A system comprising a D / A converter to convert the signal. 34. The system of claim 33, wherein the current amplifying means is formed on an IC, and the current-voltage converting means is provided separately from the outside of the IC. 34. The apparatus of claim 33, wherein the input signal is input to the current amplifying means through a coupling capacitor, the current amplifying means and the current-voltage converting means are directly connected by a direct current bias method, and the current-voltage converting means. And a negative feedback means is coupled between the output terminal of the current-to-voltage converting means and the input terminal of the current amplifying means to maintain the bias of the output terminal of the output terminal. 37. The system of claim 36, wherein the negative feedback means is controlled by a pedestal level clamp pulse of the input signal. 34. The system of claim 33, wherein the plurality of amplifiers are formed on an IC independently of each other. 34. The system of claim 33, wherein the plurality of amplifiers are formed on one semiconductor substrate. 34. The system of claim 33, wherein each amplifier is formed on one semiconductor substrate. 34. The apparatus of claim 33, further comprising an analog switch circuit for selectively transferring a predetermined one of the plurality of input signals, wherein the analog switch circuit carries out its signal transfer by controlling its anode potential by a control transistor. A system comprising a diode consisting of a controlling transistor. 42. The apparatus of claim 41, wherein the current-voltage converting means includes impedance means for converting the synthesized current generated by the current synthesizing means into the output voltage signal, and the CRT is adapted to an output voltage signal generated by the impedance means. Electron emission means for emitting electrons having their energy controlled by the cathode from the cathode and a fluorescent member for emitting light corresponding to the energy of the emitted electrons, wherein the energy of the electrons is an output voltage signal generated by the impedance means; System controlled by 45. The apparatus according to claim 44, wherein said amplifying means further comprises means for forming a plurality of current signals to which said voltage-to-current converting means are coupled between said amplifying circuits and to be applied to said amplifying circuits. A dog is applied to each one of said amplification circuits. 34. The system of claim 33, wherein the current amplifying means is formed on an IC, and the current-voltage converting means is provided outside the IC. 42. The system of claim 41 wherein each of the current amplifier circuits comprises means for n times the current signal received by the current amplifier circuit, where n is an integer. 45. The system of claim 44, wherein each of the current amplifier circuits comprises a current mirror circuit having a reference transistor and a plurality of output transistors coupled to the reference transistor such that the flow of their current is controlled by the reference transistor. The method of claim 45, wherein generating a current signal (I _X) is to have the same temperature characteristics and 1 of the current sinhojung and also includes a current signal generation means for generating a current signal (I _X), wherein in the current mirror circuit The current signal (I _IN ) to be applied to the reference transistor is determined by the difference between the generated current signal (I _X ) and the current signal. 46. The system of claim 45, wherein the reference transistor and the output transistor in the current amplifier circuit are bipolar NPN transistors. A current amplifier formed on one semiconductor substrate and processing an image signal, comprising: a first terminal to which an input signal is applied from outside of the semiconductor substrate corresponding to the video signal, and the first terminal to receive the input signal A current amplifying means coupled to and supplied with an amplified output current according to the input signal, a second terminal to which a current-voltage converting circuit to be coupled to the outside of the semiconductor substrate is coupled and to which the amplified output current is applied; A third terminal coupled to receive an output voltage to be applied in the current-voltage conversion circuit, and coupled between the third terminal and an input terminal of the current amplifying means, thereby biasing the bias voltage of the output terminal of the current-voltage conversion circuit. And negative feedback means for maintaining at a predetermined potential, wherein the current amplifying means is in accordance with the input signal in response to the input signal. By a plurality of current amplifying circuits and a plurality of current amplifying circuits which are coupled to the current-voltage converting means for generating an input current signal, each of which is coupled to the voltage-current converting means to form a current signal amplified according to the input current signal. And a current synthesizing means for synthesizing each formed amplified current signal to form a synthesized current, and supplying the synthesized current to the current-voltage converting means. 51. The apparatus of claim 50, further comprising switching means coupled between an output terminal of the negative feedback means and the input terminal of the current amplifying means to selectively form a feedback loop, wherein the switching means is controlled by a predetermined pulse. Current amplifier. 55. The current amplifier of claim 54, wherein the current-voltage converting means includes impedance means for converting the synthesized current generated by the current synthesizing means into the output voltage. 52. The apparatus of claim 51, wherein said amplifying means further comprises means for forming a plurality of current signals coupled between said voltage-current converting means and said current amplifier circuit to be applied to said current amplifier circuit. One of the current amplifiers applied to one of the amplifier circuits. 51. The current amplifier of claim 50, wherein each of the current amplifier circuits comprises means for n times (where n is an integer) the current signal applied to the current amplifier circuit. 53. The current amplifier of claim 52, wherein each of the current amplifier circuits comprises a current mirror circuit having a reference transistor and a plurality of output transistors coupled to the reference transistor such that the flow of their current is controlled by the reference transistor. The method of claim 53, wherein generating a current signal (I _X) is to have the same temperature characteristics and 1 of the current sinhojung and also includes a current signal generation means for generating a current signal (I _X), wherein in the current mirror circuit The current amplifier (I _IN ) to be applied to the reference transistor is determined by the difference between the generated current signal (I _X ) and the current signal. 55. The current amplifier of claim 54 wherein the reference transistor and the output transistor in the current amplifier circuit are bipolar NPN transistors.

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