KR940005291Y1 - Removing device for iris oscillation of camcorder - Google Patents

Abstract

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Description

Aperture Rash Removal Device for Camcorders

1 is an overall configuration diagram of an aperture control device of a conventional camcorder.

2 is an overall configuration diagram of an aperture oscillation control device of the camcorder of the present invention.

3 is a circuit diagram according to FIG.

Figure 4 (a) is a waveform diagram showing the control characteristics of the conventional DC voltage (V _DC ) and the aperture, (b) is a waveform diagram showing the aperture control according to the present invention.

* Explanation of symbols for main parts of the drawings

1: luminance and chroma signal processing unit 2: buffer unit

3: aperture control unit 4: aperture motor drive unit

5: aperture motor 6: signal processing unit

7: signal level limiting part R1-R11: resistance

D1, D2: Diode C1-C3: Capacitor

Q1, Q2: Transistor OP1: Operational Amplifier

The present invention relates to the control of the aperture (IRIS) of the camcorder (Camcordor), and more particularly to the apparatus for removing the iris oscillation of the camcorder to prevent the repeated opening and closing of the aperture generated when shooting a strong light source or the sun.

In general, an aperture control device of a camcorder generates a luminance and chroma signal processor 1 for generating and processing luminance and chroma signals, and a luminance signal detected by the luminance and chroma signal processor 1, as shown in FIG. A diaphragm for rectifying and integrating the buffer unit 2 and the signal processing unit 6 for receiving and buffering Y and the luminance signal Y buffered in the buffer unit 2 to generate an aperture control control signal. The control unit 3 and the aperture motor driver 4 for generating a signal for driving the aperture motor 5 by using the aperture control signal generated by the aperture control unit 3.

Referring to the operation of the prior art configured as described above, the luminance signal Y generated by the luminance and chroma signal processing unit 1 is applied to the buffer unit 2 and the signal processing unit 6 to process the luminance signal Y. The luminance signal Y through the buffer unit 2 is rectified and integrated in the aperture control unit 3 to output a DC value V _DC corresponding to the average brightness of the image photographed through the lens.

Accordingly, as shown in FIG. 4A, the average value of the luminance signal Y is amplified by comparing the average value of the luminance signal Y with the direct current value (base value) set by the crab motor driver 4 by external adjustment. By using this signal as a negative drive signal of the aperture motor driver 4, the aperture motor 5 is driven by a voltage difference from the positive drive signal (+ V _CC ) of the aperture motor 5. Let's go.

That is, when photographing a subject having a high luminance component, the detected high luminance signal is output through a buffer unit 2 at a high DC value for detection and integration. The DC value is non-inverted and amplified by the diaphragm motor driving unit 4 and output as a (-) drive signal. Since the voltage difference with the (+) drive becomes small, the diaphragm motor 5 is driven in the direction of closing the diaphragm. .

However, such an aperture control device of a conventional camcorder operates to close the aperture for a high luminance image and opens the aperture for a low luminance signal to obtain an appropriate luminance level. When shooting a strong light source (incandescent, lighting) directly, the brightness level is high, so the DC value (V _DC ) integrated in the aperture control unit 3 increases, so that the output value (-drive) of the aperture motor drive unit 4 is equal to the + drive value. In this case, the aperture of the lens is completely closed.

When the iris is completely closed, the luminance level becomes close to zero, and the voltage output by being integrated by the iris control unit 3 is low, so that the output value (-drive) of the iris motor driver 4 and the + of the iris motor 5 are reduced. The voltage difference from the drive value increases, which opens the iris a lot.

Therefore, there was a problem that the diaphragm oscillation phenomenon in which the opening and closing of the aperture is repeatedly repeated.

In order to solve such a conventional problem, the aperture opening and closing oscillation occurring in a zoom lens without an ND filter when taking a strong light source or sunlight is clipped to remove a high level of a luminance signal for controlling aperture during signal processing. A device for removing the diaphragm oscillation of a camcorder, which will be described in detail with reference to the accompanying drawings.

2 is an overall configuration diagram of the diaphragm oscillation removal device of the inventive camcorder, and FIG. 3 is a circuit diagram of an embodiment according to the present invention. As shown in FIG. 3, the chromaticity and luminance signal (Y) is output from a charge coupled device (CCD) output signal. A luminance and chroma signal processor 1 for detecting a signal, a signal processor 6 for processing the luminance signal Y detected by the luminance and chroma signal processor 1, and the luminance signal Y. Q1) and the buffer unit 2 buffered through the resistor R1, and the luminance signal Y buffered by the buffer unit 2 and a capacitor grounded with the diodes D1, resistors R2 and R3. The aperture control unit 3 rectifying and integrating by (C1) and the luminance signal Y integrated by the aperture control unit 3 are input to the non-inverting input (+) of the operational amplifier OP1 through the resistor R4. and the inverting input (-), and supplies the appropriate DC voltage by the variable resistor is grounded (V _R1) and a resistor (R8), the authentication operation Aperture motor driver 4 for non-inverting and amplifying the output of device OP1 as inverting input (-) through capacitor C2 and resistor R6, respectively, and non-inverted and amplified by aperture motor driver 4 In the aperture control device of a camcorder comprising an aperture motor (5) having an output as a negative drive and a power supply voltage (+ V _CC ) as a positive drive to open and close an aperture by a difference between two voltages. The luminance signal Y level through (2) is applied to the emitter of the transistor Q2 by the diode D2 and the grounded resistor R11 and the capacitor C3 at a value of completely closing the aperture, and the transistor ( On the base of Q2), a signal level limiting part 7 that can be clipped to a high level to V _E2 + V _D2 is applied by applying a reference voltage (+ V _CC ) by a resistor R9 and a grounded resistor R10. To configure.

Referring to the operation and effects of the present invention configured as described above with reference to the voltage waveform diagram shown in FIG.

First, the luminance signal Y detected by the luminance and chroma signal processing unit 1 is supplied to the signal level limiting unit 7 via the buffer unit 2, which is supplied from the signal level limiting unit 7. Since the (Y) level is applied to the emitter of the transistor Q2 by the diode D2 and the grounded resistor R11 and the capacitor C3, the on-voltage (D) of the diode D2 as shown in FIG. V _D2 ) is high-cliffed by the sum (V _D2 + V _E2 ) of the DC voltage V _E2 caused by the fixed bias. That is, the high cliff voltage V _D2 + V _E2 may be set to the maximum value of the luminance signal level such that the luminance signal integrated value does not reach the point where the aperture is completely closed.

The luminance signal Y, which is clipped to the high level, is rectified by the diode D1 and then integrated by the resistor R1 and the grounded resistor R3 and the condenser C1, and the operational amplifier through the resistor R4. It is supplied to the non-inverting pressure stage (+) of (OP1), and a reference voltage for adjusting the aperture is applied to the inverting input terminal (-) of the operational amplifier (OP1) through the variable resistor (V _R1 ), thereby non-inverting according to the luminance integral value. The amplification is performed to output the aperture motor drive signal (-drive) so that the luminance level is always constant.

Accordingly, the diaphragm motor 5 receives a power supply voltage (+ V _CC ) to the (+) drive and a non-inverted amplification signal to the (-) drive to open and close the diaphragm according to the voltage difference.

As described in detail above, the present invention has an effect of eliminating the oscillation phenomenon in which the opening and closing of the aperture are repeated without an ND filter or other vehicle blocking device when photographing sunlight or a strong light source.

Claims (2)

A buffer unit 2 and a signal processor 6 for buffering and processing the luminance signal detected by the luminance and chroma signal processor 1, an aperture control unit 3 for rectifying and integrating the buffered luminance signal, and the integration A diaphragm control device of a camcorder comprising an aperture motor driver (4) for comparing an amplified luminance signal value with a predetermined reference voltage and controlling the aperture motor (5) with the non-inverted and amplified DC value, wherein the buffer unit (2) To remove the oscillation oscillation of the camcorder, characterized in that it comprises a signal level limiting unit (7) for limiting the level so that the luminance signal level value detected at is not reached the level at which the opening and closing of the aperture is repeated. Device. The signal level limiting unit (7) of claim 1, wherein the detected luminance signal is applied to the emitter of the transistor (Q2) through the diode (D2) and the grounded resistor (R11) and the capacitor (C3). A device for diaphragm oscillation removal of a camcorder, characterized in that a voltage (+ V _CC ) divided by a resistor (R9) and a grounded resistor (R10) is applied to the base of the transistor (Q2).