KR100262337B1 - A current controlled fed driving circuit for gray scale processing using the switched resister - Google Patents

A current controlled fed driving circuit for gray scale processing using the switched resister Download PDF

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KR100262337B1
KR100262337B1 KR1019970064941A KR19970064941A KR100262337B1 KR 100262337 B1 KR100262337 B1 KR 100262337B1 KR 1019970064941 A KR1019970064941 A KR 1019970064941A KR 19970064941 A KR19970064941 A KR 19970064941A KR 100262337 B1 KR100262337 B1 KR 100262337B1
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South Korea
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driving circuit
operational amplifier
switched
switched resistor
resistors
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KR1019970064941A
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Korean (ko)
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KR19990043894A (en
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신홍재
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김영남
오리온전기주식회사
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0264—Details of driving circuits
    • G09G2310/027—Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G09G2330/021—Power management, e.g. power saving

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

PURPOSE: A driving circuit for a gray scale processing field emission device of current control type using a switched resistor is provided to reduce the chip size and the power dissipation by varying resistance using a switch, that is, by using one operational amplifier to which a plurality of resistors are connected, which enables to vary resistance in more than 4 different levels. CONSTITUTION: The driving circuit includes a switched resistor(14). The switched resistor is coupled with one terminal of a terminal of voltage follower, controls the current output from the single operational amplifier with response to data applied from outside, so as to perform multiple level gray scale control. The switched resistor further includes MOS transistors(N3,N4,N5,N6) and resistors(R2,R2,R3,R4,R5) which make plurality of sets one by one. The MOS transistors are turned on/off by the data fro outside and are used to vary the resistance as switches. The resistors are coupled with one terminal of the MOS transistors and the other terminals of the resistors are grounded. The plurality of sets are coupled with the voltage follower in parallel.

Description

스위치드 저항을 사용한 전류제어 방식의 계조처리 전계방출표시소자 구동회로Current control type gradation field emission display device driving circuit using switched resistor

본 발명은 스위치드 저항을 사용한 전류제어 방식의 전계방출표시소자(FED) 구동회로에 관한 것으로, 스위치를 통해 저항값을 조절하여 1개의 연산증폭기만으로도 4레벨 이상의 밝기를 조절할 수 있도록 하므로써, 구동회로의 면적을 줄임과 동시에 전력소모를 절감시키는 기술에 관한 것이다.BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission display device (FED) driving circuit of a current control method using a switched resistor. By controlling a resistance value through a switch, the brightness of four or more levels can be controlled by only one operational amplifier. The present invention relates to a technology for reducing power consumption while reducing area.

일반적으로 전계방출표시소자의 구동회로는 전류미러를 통상적으로 이용하여 계조처리를 해오고 있는데, 이는 회로 특성상 약간은 불안정한 출력특성을 가지는 단점이 있다.In general, the driving circuit of the field emission display device has generally been subjected to gradation processing using a current mirror, which has a disadvantage in that the circuit characteristics are slightly unstable.

현재에는 상기와 같은 단점을 보완하기 위해 전류미러 방식 대신 연산증폭기를 사용하여 전계방출표시소자를 구동하고 있는데 이는 제1도에 도시된 바와 같이, 기준전압(Vref)과 노드 1을 통해 피드-백된 전압을 차연산하여 증폭하는 연산증폭기(10)를 통해 출력된 전압은 에미터(11)(일명 '팁'이라고도 칭함)에 직렬로 연결된 N-MOS 트랜지스터(N1)를 턴-온시키고, 이때 컬럼 어드레스 신호 또는 로우 어드레스 신호(S1)에 의해 턴-온/오프되는 N-MOS 트랜지스터(N2)에 온되어 있으면 상기 연산증폭기(10)에서 출력된 전압을 통해 각 트랜지스터(N1, N2)에 전류가 흐르게 된다.Currently, to compensate for the above drawbacks, the field emission display device is driven by using an operational amplifier instead of the current mirror method, which is fed back through the reference voltage Vref and the node 1, as shown in FIG. The voltage output through the operational amplifier 10 for differentially amplifying and amplifying the voltage turns on the N-MOS transistor N1 connected in series to the emitter 11 (also called a 'tip'), where the column When the N-MOS transistor N2 is turned on / off by the address signal or the row address signal S1, current is applied to each of the transistors N1 and N2 through the voltage output from the operational amplifier 10. Will flow.

이때 출력되는 출력전류 I는 노드 1에 연결된 저항(R1)을 통해 Vref/R 값으로 출력된다.At this time, the output current I is output as a Vref / R value through the resistor R1 connected to the node 1.

이에 따라 에미터(11)에서는 전자가 생성되고 이 전자는 게이트(12)에 인가된 고전압(이 고전압은 애노드(13)에 인가되는 전압 보다 낮은 고전압임)에 의해 방출된다.Accordingly, the emitter 11 generates electrons, which are emitted by the high voltage applied to the gate 12, which is lower than the voltage applied to the anode 13.

상기 애노드(13)에서는 상기 게이트(12)에 의해 방출된 전자들을 홀쪽으로 가속시키며, 이때 애노드(13)의 배면에는 형광막(도면에는 도시하지 않음)이 도포되어 있어, 충돌되는 전자량에 해당하는 광을 발생하여 화상이 표시되도록 한다.The anode 13 accelerates the electrons emitted by the gate 12 toward the hole, and a fluorescent film (not shown) is coated on the back surface of the anode 13 to correspond to the amount of electrons colliding with each other. Light is generated so that an image is displayed.

상기와 같은 기술은 미국 특허 5,157,309호에 이미 공지된 기술로써 더욱 상세한 설명은 생략하며, 상기와 같이 연산증폭기를 사용하는 구동회로는 전류미러 방식에 비해서 안정적인 출력특성을 가지는 장점이 있고, 또한 기준전압값(Vref)을 외부에서 조절하므로써 펄스폭변조방식(PWM)에도 적용이 가능한 잇점을 수반한다.The above technique is already known in US Pat. No. 5,157,309, and a detailed description thereof is omitted. The driving circuit using the operational amplifier as described above has an advantage of having a stable output characteristic compared to the current mirror method, and also a reference voltage. It also has the advantage of being applicable to the pulse width modulation method (PWM) by adjusting the value (Vref) externally.

그러나 상기와 같은 방식의 전류원은 하나의 저항과 하나의 연산증폭기로 구성되어 있고, 전류량을 조절하기 위해서는 입력전압과 저항값을 조정하여 조절하게 된다.However, the current source in the above manner is composed of one resistor and one operational amplifier, and in order to adjust the amount of current, the input voltage and the resistance value are adjusted.

따라서 이 회로를 사용하여 16레벨의 밝기를 조절하기 위해서는 4개의 연산 증폭기와 4개의 저항이 필요하게 된다.Therefore, four op amps and four resistors are needed to adjust the brightness at 16 levels using this circuit.

물론 그 이상의 밝기 조절이나 칼라를 만들때에도 마찬가지이다.Of course, the same can be said for creating more brightness and colors.

이에 따라 연산증폭기의 사용으로 인해 회로가 복잡해질 뿐만 아니라 면적을 크게차지하는 단점이 있다.Accordingly, the use of the operational amplifier not only complicates the circuit but also has a disadvantage of occupying a large area.

본 발명은 상기와 같은 문제점을 감안하여, 스위치를 사용하여 저항값을 조절하는 방식을 통해, 1개의 연산증폭기만을 사용하고 여기에 여러개의 저항을 연결할 수 있도록 하여 4레벨 이상의 밝기를 조절 가능케 하므로써, 면적을 줄임과 동시에 연산증폭기에서 소모되는 전력을 줄이는 것을 목적으로 한다.In view of the above problems, by using a switch to adjust the resistance value, by using only one operational amplifier and by connecting a plurality of resistors to this, by enabling the brightness of four or more levels, It aims to reduce the area and at the same time reduce the power consumed by the operational amplifier.

제1도는 일반적인 연산증폭기를 사용하는 전계방출표시소자 구동회로를 나타내는 회로도.1 is a circuit diagram showing a field emission display device driving circuit using a general operational amplifier.

제2도는 본 발명에 의해 구현된 전계방출표시소자 구동회로를 나타내는 회로도.2 is a circuit diagram showing a field emission display device driving circuit implemented by the present invention.

* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings

10 : 연산증폭기 11 : 에미터10: operational amplifier 11: emitter

12 : 게이트 13 : 애노드12: gate 13: anode

14 : 스위치드 저항수단14: switched resistance means

상기와 같은 목적을 달성하기 위한 구동회로의 구성은, 단일의 연산증폭기와 전압팔로워 수단으로 구성되어, 전류제어방식을 통해 단일 계조처리를 행하는 전계 방출표시소자 구동회로에 있어서,The structure of the drive circuit for achieving the above object is composed of a single operational amplifier and a voltage follower means, in the field emission display device drive circuit for performing a single gradation process through a current control method,

상기 전압팔로워 수단의 일측에 연결되어, 외부에서 인가되는 데이타에 따라 상기 단일의 연산증폭기에서 출력되는 전류값을 제어해, 다수의 계조처리를 행하도록 하는 스위치드 저항수단을 포함하여 구성되고,It is connected to one side of the voltage follower means, it comprises a switched resistor means for controlling the current value output from the single operational amplifier in accordance with the data applied from the outside to perform a plurality of gradation processing,

상기 스위치드 저항수단은 외부에서 입력되는 데이타에 의해 턴-온/오프되며, 저항값을 변화시키기 위해 사용되는 스위치 역할의 MOS 트랜지스터와;The switched resistor means includes a MOS transistor which is turned on / off by externally input data and is used to change a resistance value;

일측은 상기 MOS 트랜지스터의 일측에 연결되고, 타측은 접지상태인 저항으로 일조를 이루며;One side is connected to one side of the MOS transistor and the other side is made up of a resistor which is grounded;

상기 일조의 형태를 전압팔로워 수단에 병렬로 다수쌍 연결하여 구성하는 것을 특징으로 한다.It is characterized in that the configuration of the plurality of pairs in parallel connected to the voltage follower means.

상술한 목적 및 특징들, 장점은 첨부된 도면과 관련한 다음의 상세한 설명을 통하여 보다 분명해질 것이다. 이하 첨부된 도면을 참조하여 본 발명의 실시예를 상세히 설명하며, 종래와 같은 구성은 동일부호를 부여하여 설명한다.The above objects, features, and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

제2도는 본 발명에 의해 구현된 전계방출표시소자의 구동회로에 관한 것으로, 연산증폭기(10)에서 출력되는 전류는 N-MOS 트랜지스터(N1)의 일측에 연결된 스위치드 저항수단(14)에 의해 제어되어 에미터(11)로 흐르게 되는 바, 상기 스위치드 저항수단(14)의 구성은 다음과 같이 이루어진다.2 is related to the driving circuit of the field emission display device implemented by the present invention, the current output from the operational amplifier 10 is controlled by a switched resistor means 14 connected to one side of the N-MOS transistor (N1) And flows to the emitter 11, the configuration of the switched resistance means 14 is as follows.

외부에서 입력되는 데이타(D0∼D3)에 의해 턴-온/오프되며, 에미터(11)로 인가되는 전류값을 변화시키기 위해 사용되는 스위치 역할을 하는 N-MOS 트랜지스터(N3)와, 일측은 상기 N-MOS 트랜지스터(N3)의 일측에 연결되고, 타측은 접지 상태인 저항(R2)으로 일조를 이루며, 이를 통해 하나의 연산증폭기에서 16레벨의 계조처리를 가능케 한다.An N-MOS transistor N3 that is turned on / off by externally input data D 0 to D 3 and serves as a switch used to change a current value applied to the emitter 11, One side is connected to one side of the N-MOS transistor N3, and the other side is formed of a resistor R2 in a ground state, thereby enabling 16 levels of gradation processing in one operational amplifier.

그리고 상기와 같은 일조의 형태가 상기 노드 1에 병렬로 4쌍이 연결되어 스위치드 저항수단(14)을 이룬다.In addition, as described above, four pairs are connected to the node 1 in parallel to form the switched resistance means 14.

상기와 같은 구성의 스위치드 저항수단(14)을 포함하는 구동회로의 전체 동작을 설명하면, 외부에서 입력되는 데이타 중 '하이' 상태인 데이타가 입력되는 N-MOS 트랜지스터가 턴-온되고, 이 N-MOS 트랜지스터의 턴-온 상태에 따라 에미터(11)로 인가되는 전류는 상기 턴-온된 N-MOS 트랜지스터에 연결된 저항값에 의해 결정된다.Referring to the overall operation of the drive circuit including the switched resistance means 14 of the above configuration, the N-MOS transistor to which the data of the 'high' state of the data input from the outside is input is turned on, this N The current applied to the emitter 11 according to the turn-on state of the MOS transistor is determined by the resistance value connected to the turned-on N-MOS transistor.

이를 수식으로 설명하면 연산증폭기(10)와 N-MOS 트랜지스터(N1)로 구성된 전압 팔로워(Voltage Follower)는 궤환을 통하여 일정한 전류가 흐르게 되고, 스위치드 저항단(14)의 등가저항을 A라 하면 이 회로를 통하여 흐르는 전류는 다음과 같다.In this case, a voltage follower composed of the operational amplifier 10 and the N-MOS transistor N1 flows a constant current through the feedback, and the equivalent resistance of the switched resistor stage 14 is A. The current flowing through the circuit is as follows.

스위치드 저항값을 조절하는 스위치인 데이타 입력단자(D0∼D3)로 데이타가 입력되면 즉, 하이신호가 인가되면 저항값이 바뀌게 되어 출력 또한 I = Vref / A로 바뀌게 된다.When data is input to the data input terminals D 0 to D 3 , which are switches for controlling the switched resistance value, that is, when the high signal is applied, the resistance value is changed and the output is also changed to I = Vref / A.

예를 들어, 입력단자 D0에 신호가 들어오면 출력전류는 I = Vref /R2가 되고, 입력단자 D0와 D1에 데이타가 입력되면 스위치드 저항단의 저항값 A는 R2와 R3의 병렬 값인 A = (R2·R3) / (R2+R3) 값이 된다.For example, when a signal is input to the input terminal D 0 , the output current is I = Vref / R2. When data is input to the input terminals D 0 and D 1 , the resistance value A of the switched resistor stage is the parallel value of R2 and R3. A = (R2 · R3) / (R2 + R3).

즉, 저항값이 줄어드므로 흐르는 전류는 늘어나게 된다.That is, since the resistance value decreases, the flowing current increases.

한편, 반대로 R3값을 조절하여 흐르는 전류량을 늘일 수도 있다.On the other hand, it is also possible to increase the amount of current flowing by adjusting the value of R3.

만약 R2 와 R3를 동일하게 만든다면 A = R2 / 2 이므로 I = 2Vref / R2로 N-MOS 트랜지스터에 로우 신호가 인가된 것에 비해서 2배의 전류가 흐르게 된다.If R2 and R3 are made equal, A = R2 / 2, so I = 2Vref / R2, and twice as much current flows as the low signal is applied to the N-MOS transistor.

이와 같은 방식을 사용하여 입력단자 D3와 D4에도 신호가 인가되면 이 회로를 통해 흐르는 전류는 조절할 수 있으므로 16 단계의 밝기 조절을 할 수 있는 전계방출표시소자 구동회로에 사용할 수 있다.When a signal is applied to the input terminals D 3 and D 4 in this manner, the current flowing through the circuit can be adjusted, and thus it can be used in the field emission display device driving circuit which can adjust the brightness of 16 steps.

물론 16단계 이상의 밝기를 조절하는 구동회로에도 확장 가능하다.Of course, it can be extended to the driving circuit that adjusts the brightness over 16 levels.

이상에서 상세히 설명한 바와 같이 본 발명은 연산증폭기를 사용하는 기존의 방식에 비해 사용되는 연산증폭기의 수를 줄일 수 있어 전체 설계 면적이 줄어드는 잇점이 있으며, 이에 따라 전력소모 또한 줄일 수 있는 잇점이 있다.As described in detail above, the present invention can reduce the number of operational amplifiers used compared to the conventional method using the operational amplifier, thereby reducing the overall design area, and thus reducing the power consumption.

그리고 이와 같은 전류제어 방식은 전류제어 방식을 사용하는 모든 전계방출 표시소자 구동회로에 사용할 수 있는 장점이 있다.In addition, the current control method has an advantage that it can be used in all the field emission display device driving circuit using the current control method.

아울러 본 발명의 바람직한 실시예는 예시의 목적을 위해 개시된 것이며, 당업자라면 본 발명의 사상과 범위안에서 다양한 수정, 변경, 부가등이 가능할 것이며, 이러한 수정 변경 등은 이하의 특허 청구의 범위에 속하는 것으로 보아야 할 것이다.In addition, a preferred embodiment of the present invention is disclosed for the purpose of illustration, those skilled in the art will be able to make various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the following claims You will have to look.

Claims (1)

단일의 연산증폭기와 전압팔로워 수단으로 구성되어, 전류제어방식을 통해 단일 계조처리를 행하는 전계 방출표시소자 구동회로에 있어서,A field emission display device driving circuit comprising a single operational amplifier and a voltage follower means for performing a single gradation process through a current control method, 상기 전압팔로워 수단의 일측에 연결되어, 외부에서 인가되는 데이타에 따라 상기 단일의 연산증폭기에서 출력되는 전류값을 제어해, 다수의 계조처리를 행하도록 하는 스위치드 저항수단을 포함하여 구성되고,It is connected to one side of the voltage follower means, it comprises a switched resistor means for controlling the current value output from the single operational amplifier in accordance with the data applied from the outside to perform a plurality of gradation processing, 상기 스위치드 저항수단은 외부에서 입력되는 데이타에 의해 턴-온/오프되며, 저항값을 변화시키기 위해 사용되는 스위치 역할의 MOS 트랜지스터와;The switched resistor means includes a MOS transistor which is turned on / off by externally input data and is used to change a resistance value; 일측은 상기 MOS 트랜지스터의 일측에 연결되고, 타측은 접지상태인 저항으로 일조를 이루며;One side is connected to one side of the MOS transistor and the other side is made up of a resistor which is grounded; 상기 일조의 형태를 전압팔로워 수단에 병렬로 다수쌍 연결하여 구성하는 것을 특징으로 하는 스위치드 저항을 사용한 전류제어 방식의 계조처리 전계방출표시 소자 구동회로.A gradation-processing field emission display device driving circuit according to the current control method using a switched resistor, characterized in that a plurality of pairs are connected in parallel to a voltage follower means.
KR1019970064941A 1997-11-29 1997-11-29 A current controlled fed driving circuit for gray scale processing using the switched resister KR100262337B1 (en)

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