KR920008254Y1 - Backlight-compensative circuit in video camera - Google Patents
Backlight-compensative circuit in video camera Download PDFInfo
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- KR920008254Y1 KR920008254Y1 KR2019890020547U KR890020547U KR920008254Y1 KR 920008254 Y1 KR920008254 Y1 KR 920008254Y1 KR 2019890020547 U KR2019890020547 U KR 2019890020547U KR 890020547 U KR890020547 U KR 890020547U KR 920008254 Y1 KR920008254 Y1 KR 920008254Y1
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
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- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
- H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
- H03K17/60—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being bipolar transistors
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K19/00—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits
- H03K19/20—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits characterised by logic function, e.g. AND, OR, NOR, NOT circuits
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
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Abstract
내용 없음.No content.
Description
제1도는 본 고안에 따른 회로도.1 is a circuit diagram according to the present invention.
제2도는 종래의 회로도.2 is a conventional circuit diagram.
제3도는 본 고안에 의한 역광보정시의 파형과 종래의 파형을 비교한 도면.Figure 3 is a view comparing the waveform and the conventional waveform at the time of backlight compensation according to the present invention.
* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings
10 : 셋업레벨제어부 20 : 휘도신호이득제어부10: setup level control unit 20: luminance signal gain control unit
30 : 제1레벨전압설정부 40 : 휘도신호처리부30: first level voltage setting unit 40: luminance signal processing unit
50 : 비교기 60 : 앤드게이트50: comparator 60: endgate
70 : 제2레벨전압설정부70: second level voltage setting unit
본 고안은 비데오 카메라의 역광보정회로에 관한 것으로 특히 휘도신호신호의 셋트업(Set Up)레벨을 올림과 동시에 휘도신호이득을 억제하여 역광보정시에도 밝은 부분에서의 화이트 클립(White Clip)이 일어나지 않도록 한 역광보정회로에 관한 것이다.The present invention relates to a backlight compensation circuit of a video camera, and in particular, raises the set-up level of the brightness signal signal and simultaneously suppresses the gain of the brightness signal so that a white clip occurs in the bright part even during backlight compensation. And a backlight compensation circuit.
종래의 비데오 카메라에 있어서의 역광보정회로는 제2도에 도시된 바와같이 비교기(50)의 비반전단자(+)에 저항(R1)과 콘덴서(C1)로 구성되는 적분회로를 접속함과 아울러 반전단자(-)에는 가변저항(VR1)과 저항(R2,R3) 및 스위치(SW1)를 직병렬 접속하여 상기 비교기(50)의 출력단을 통하여 렌즈의 조리개를 개폐시킬수 있도록 구성하였다.The backlight compensation circuit in the conventional video camera connects the integrating circuit composed of the resistor R1 and the condenser C1 to the non-inverting terminal + of the comparator 50 as shown in FIG. A variable resistor VR1, resistors R2, R3, and a switch SW1 are connected in parallel to the inverting terminal (-) to open and close the aperture of the lens through the output terminal of the comparator 50.
즉, 역광보정시에는 정상시보다 렌즈의 조리개를 더 열어주므로 보고자 하는 피사체를 밝게해줄 수 있었으나, 이 때문에 피사체의 주변이 더욱 밝아져 결국 화이트클립이 일어나게되는 문제점이 있었다.In other words, when backlight compensation, the aperture of the lens was opened more than normal, so that the subject to be seen could be brightened. However, the surrounding of the subject became brighter, resulting in a white clip.
본 고안은 상기와 같은 종래의 문제점을 해결하기 위하여 안출한 것으로 역광보정시 조리개를 더 열어주지않고 휘도신호신호의 셋트업레벨을 올려 주므로서 보고자 하는 피사체를 밝게해줌으로 물론 휘도신호이득을 일정향 이하로 억제해주므로 휘도신호신호가 전체적으로 올라가 밝은 주변이 클립되는 것을 방지할 수 있도록 한것이다.The present invention has been devised to solve the above-mentioned problems. As a result, the brightness of the subject to be brightened by raising the set-up level of the luminance signal signal without opening the iris further during backlight compensation, of course, improves the luminance signal gain. Since it suppresses below, the luminance signal signal rises as a whole to prevent the bright surroundings from being clipped.
상기와 같은 목적을 달성하기 위하여 본 고안은 역광보정모드의 선택을 위한 역광보정모드 스위치(SW1), 상기 역광보정모드 스위치(SW1)의 온/오프에 따라 설정전압의 레벨을 가변시키는 제1전압레벨설정부(30), 입력휘도신호(휘도신호)의 레벨을 상기 전압레벨설정부(30)에 의하여 설정된 전압에 의하여 조절하기 위한 셋트업레벨제어부(10), 상기 셋트업레벨제어부(10)에서 레벨이 조절된 휘도신호를 버퍼링한 후에 적분하는 휘도신호처리부(40), 상기 휘도신호처리부(40)의 출력신호와 소정의 기준레벨을 비교하기 위한 비교기(50), 상기 비교기(50)로 부터의 출력신호와 상기 역광보정스위치의 온/오프에 따른 하이/로우레벨의 제어신호를 논리곱연산하기 위한 AND게이트(60), 상기 AND게이트(60)로 부터의 출력신호의 논리상태에 따라 출력전압의 레벨을 가변시키는 제2전압레벨설정부, 및 상기 제2전압레벨설정부의 전압레벨에 따라 상기 셋트업레벨제어부(10)로부터의 휘도신호의 이득을 제어하기 위한 휘도신호 이득제어부(20)를 포함하는 것을 특징으로 한다.In order to achieve the above object, the present invention provides a first voltage for varying a level of a set voltage according to on / off of a backlight compensation mode switch SW1 and a backlight compensation mode switch SW1 for selecting a backlight compensation mode. A setup level controller 10 for adjusting the level of the input luminance signal (luminance signal) by the voltage set by the voltage level setup unit 30, and the setup level controller 10. In the luminance signal processing unit 40, the comparator 50 for comparing the output signal of the luminance signal processing unit 40 with a predetermined reference level after buffering the luminance signal whose level is adjusted to AND gate 60 for performing an AND operation on the output signal from and the high / low level control signal according to the on / off of the backlight compensation switch, and according to the logic state of the output signal from the AND gate 60. When the output voltage level is variable Includes a second voltage level setting unit and a luminance signal gain control unit 20 for controlling the gain of the luminance signal from the setup level controller 10 according to the voltage level of the second voltage level setting unit. It is done.
이를 첨부된 도면을 참조하여 더욱 상세히 설명한다.This will be described in more detail with reference to the accompanying drawings.
제1도에 도시된 본 고안은 역광보정모드의 선택을 위한 역광보정스위치(SW1)와, 상기 역광보정모스위치의 일단에 접속되어 공급전원(Vcc)과 접지단자사이에 병렬로 접속되는 저항(R1,R2)과 상기 저항들에 직렬접속되는 가변저항(VR1)으로 구성되어 전압의 레벨을 가변시키는 제1전압레벨설정부(30)와, 상기 제1전압레벨설정부(30)에 의하여 설정된 전압레벨에 따라 입력되는 휘도신호(휘도신호)의 셋트업레벨을 제어하기 위한 셋트업레벨제어부(10)와, 상기 레벨제어부(10)에 의하여 레벨변경된 휘도신호를 버퍼링하고 이를 적분하는 휘도신호처리부(40)와, 신호처리된 휘도신호와 소정의 기준레벨과 비교하기 위한 비교기(50)와, 비교기의 비교신호와 역광보정스위치(SW1)의 온/오프에 따른 하이/로우레벨의 제어신호를 논리곱연산하기 위한 AND게이트(60)와, AND게이트(60)로 부터의 출력신호의 논리상태에 따라 출력전압의 레벨을 가변시키는 제2전압레벨설정부(70)와, 제2전압레벨설정부(70)의 전압레벨에 따라 셋트업레벨제어부(10)로 부터의 휘도신호의 이득을 제어하기 위한 휘도신호이득제어부(20)로 구성된다.The present invention shown in FIG. 1 has a backlight compensation switch SW1 for selecting a backlight compensation mode and a resistor connected to one end of the backlight compensation mother switch and connected in parallel between a power supply Vcc and a ground terminal. A first voltage level setting unit 30 configured to change a level of a voltage, which is composed of R1 and R2 and a variable resistor VR1 connected in series with the resistors, and set by the first voltage level setting unit 30. A setup level controller 10 for controlling the setup level of the luminance signal (luminance signal) input according to the voltage level, and a luminance signal processor for buffering and integrating the luminance signal changed by the level controller 10 and integrating the same. 40, a comparator 50 for comparing the signal processed luminance signal with a predetermined reference level, and a comparison signal of the comparator and a high / low level control signal according to on / off of the backlight compensation switch SW1. AND gate 60 for AND operation A second voltage level setting unit 70 for varying the level of the output voltage according to the logic state of the output signal from the drive signal 60, and a setup level control unit according to the voltage level of the second voltage level setting unit 70. And a luminance signal gain control unit 20 for controlling the gain of the luminance signal from (10).
이와같은 구성에 따른 역광보정회로의 동작은 같다.The operation of the backlight compensation circuit according to such a configuration is the same.
통상적인 촬영시에는 역광보정스위치(SW1)가 오프되고 상기 스위치(SW1)와 연동하여 동작하는 제1전압설정부(30)내의 스위치(SW2)도 오프상태로 있게되어 저항(R2)과 가변저항(VR1)으로 정해진 전압에 의해 제3도의 (a)와 같이 셋트업 레벨(NTSC신호에서 일반적으로 7.5IRE)이 결정되고 동시에 제2전압설정부에서도 가변저항(VR3)과 저항(R7)에 의해 휘도신호이득(NTSC신호에서 일반적으로 100IRE)이 결정된다.During normal shooting, the backlight compensation switch SW1 is turned off, and the switch SW2 in the first voltage setting section 30 that operates in conjunction with the switch SW1 is also turned off so that the resistor R2 and the variable resistor are turned off. The setup level (typically 7.5 IRE in the NTSC signal) is determined by the voltage set as VR1 as shown in FIG. 3A, and at the same time, the variable resistor VR3 and the resistor R7 are also set in the second voltage setting section. The luminance signal gain (typically 100 IRE in NTSC signal) is determined.
만일, 역광보정이 필요한 때에는 사용자가 역광보정스위치(SW1)를 온시키면 제1전압설정부(30)내의 스위치(SW2)도 함께 온되어 셋트업레벨은 저항(R1,R2) 및 가변저항(VR1)으로 분압된 전압에 의해 결정되므로 정상시보다 셋트업레벨이 올라가게된다.When the backlight compensation is required, when the user turns on the backlight compensation switch SW1, the switch SW2 in the first voltage setting unit 30 is also turned on together, and the set-up level includes the resistors R1 and R2 and the variable resistor VR1. It is determined by the voltage divided by), so the setup level is higher than normal.
따라서, 셋트업 레벨제어부(10)를 통하여 셋트업레벨이 올라간 휘도신호신호는 휘도신호이득제어부(20)에 입력되는데 이때, 휘도신호신호가 트랜지스터(Q1)와 저항(R3,R4)으로 된 버퍼 및 저항(R5)과 콘덴서(C1)의 적분회로로 구성되는 휘도신호처리부(40)로 입력되어 버퍼링되후에 적분된 신호가 비교기(50)의 비반전단자(+)에 입력된다.Therefore, the luminance signal signal whose setup level is raised through the setup level controller 10 is input to the luminance signal gain control unit 20, where the luminance signal signal is buffered by the transistors Q1 and resistors R3 and R4. And an integrated signal which is input to the luminance signal processing unit 40 composed of an integration circuit of the resistor R5 and the capacitor C1 and then buffered, is input to the non-inverting terminal (+) of the comparator 50.
여기서, 비교기(50)의 비전단자(-)에는 가변저항(VR2)에 의해 정해진 전압이 입력되어 이 전압값은 휘도신호신호가 화이트클립이 일어나는 레벨(일반적으로 110IRE)의 휘도신호신호를 적분했을때의 DC값이 되도록 조정을 하므로 이 값보다 더 큰 휘도신호가 비교기(50)의 비반전단자(+)에 입력되면 비교기(50)의 출력단으로 하이레벨이 출력되어 결국 앤드게이트(60)의 출력단을 통하여 하이레벨이 출력된다.Here, a voltage determined by the variable resistor VR2 is input to the non-terminal terminal (-) of the comparator 50. The voltage value indicates that the luminance signal signal integrates the luminance signal signal of the level (normally 110 IRE) at which the white clip occurs. When the luminance signal larger than this value is input to the non-inverting terminal (+) of the comparator 50, a high level is output to the output terminal of the comparator 50, and eventually the end gate 60 of the AND gate 60 is adjusted. The high level is output through the output stage.
따라서, 제2전압설정부(70)내의 스위치(SW3)가 온되면서 저항(R6,R7)과 가변저항(VR3)으로 분압된 출력전압은 정상시보다 낮게되고 휘도신호신호가 클립되는 순단 휘도신호이득이 작아져서 클립이 일어나지 않게되다.Accordingly, the output voltage divided by the resistors R6 and R7 and the variable resistor VR3 while the switch SW3 in the second voltage setting unit 70 is turned on is lower than normal and the luminance signal signal is clipped. The gain is so small that no clips will occur.
다시 말해서, 스위치(SW1) 온시 셋트업레벨은 올라가고 휘도신호이득은 억제되어 휘도신호신호의 화이트클립이 일어나지 않게 되므로 제3도의 (c)와 같은 종래의 역광보정시의 파형에 비하여 (b)와 같은 파형의 역광보정을 실시할 수 있게 된다.In other words, the set-up level is increased when the switch SW1 is turned on, and the gain of the luminance signal is suppressed so that the white clip of the luminance signal signal does not occur. Thus, compared with the waveforms of the conventional backlight compensation method shown in FIG. Backlight compensation of the same waveform can be performed.
이상과 같은 본 고안은 역광보정시 휘도신호신호의 셋트업레벨을 올려주므로써 보고자 하는 피사체를 밝게해줌과 동시에 휘도신호신호가 전체적으로 올라가므로 인하여 밝은 주변이 클립되는 것을 방지하기 위하여 휘도신호 이득을 일정량이하로 억제해줄 수 있는 효과가 있다.The present invention as described above increases the set-up level of the luminance signal signal during backlight compensation to brighten the subject to be viewed and at the same time the luminance signal signal rises as a whole, so that the brightness signal gain is prevented from being clipped by a certain amount. The following effects can be suppressed.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019890020547U KR920008254Y1 (en) | 1989-12-29 | 1989-12-29 | Backlight-compensative circuit in video camera |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019890020547U KR920008254Y1 (en) | 1989-12-29 | 1989-12-29 | Backlight-compensative circuit in video camera |
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| Publication Number | Publication Date |
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| KR910013423U KR910013423U (en) | 1991-07-30 |
| KR920008254Y1 true KR920008254Y1 (en) | 1992-11-14 |
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| KR2019890020547U KR920008254Y1 (en) | 1989-12-29 | 1989-12-29 | Backlight-compensative circuit in video camera |
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- 1989-12-29 KR KR2019890020547U patent/KR920008254Y1/en not_active IP Right Cessation
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